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Little Bucks Miniature Equines
EquineStudies
I would like to share some of my assignments(my own work) I did when studying to attain my certificate III in Equine Husbandry at TAFE Trenayr Campus ,near Grafton NSW. 2004/2005
I unfortunately cannot seem to add my pictures with the text , if anyone wants a full copy of my work I can email it to you.
Oestrous Cycle
Birth
Effects of Shoeing
The Integument
Disease Control
Parasite Control
Endurance Riding
Stay Apparatus
Cold Blood Warm Blood Hot Blood
Oestrous Cycle of the Mare
The primary sex glands of the mare are the ovaries located in the abdominal cavity between the last rib and the point of the hip, suspended by the cranial part of the broad ligament of the uterus called the mesovarium. The ovaries contain many thousands of eggs or ova; she is born with her full quantity of ovaries, and will never produce any more during her life. They are released in a precisely orchestrated sequence of events controlled by several interacting hormones. The oestrous cycle commences when the mare is approximately one and half years old and continues throughout her life.This sequence is called the Oestrous Cycle.
The Oestrous cycle of the mare is initiated by a portion of the brain called hypothalamus acting through the pituitary gland located at the base of the brain. The pituitary gland produces follicle stimulating hormone (FSH). This hormone brings about development of a follicle in the ovary. These normally occur singularly, the Graafian follicle (one dominant follicle) in the mare but sometimes can develop several. The follicle can be viewed by the Veterinary via a rectal scan and is seen at different sizes depending on the stage of development, but resembles a blister on the surface of the ovary. The follicle contains an ovum and is lined with specialised cells that produce the Oestrogen, estrogenic hormones, estrone and estradiol. These hormones have a two fold effect .In the mare they bring about the period of sexual desire called estrus or heat and initiate the changes in cellular lining of the uterus to prepare it for the attachment of the fertilised ovum. Through a feed back mechanism, as oestrogen levels peak and the follicle reaches maturity, further production of FSH is inhibited and in its place, Luteinizing hormone (LH) is produced by the pituitary. LH brings about rupture of the follicle, release of the ovum, (ovulation) and counteracts oestrogen to terminate signs of heat. It also initiates development of the corpus luteum or yellow body at the site of the ruptured follicle. The corpus luteum, through production of progesterone, plays an essential role in the attachment and maintenance of the fertilised ovum. It also overrides and counteracts further FHS production temporarily. If the mare becomes pregnant, additional progesterone is produced that prevents resumption of the oestrus cycle for the duration of the pregnancy.Pregnant Mare Serum Gonadotrophin (not part of the oestrous cycle) is produced by the foetal side of the placenta, and is an important hormone to test for conformation of pregnancy. If pregnancy dose not occur, some 14-16 days later, and no egg has arrived at the uterus, it releases a substance called Prostaglandin which destroys the corpus luteum, switching of the progesterone production. The pituitary stops LH and starts FHS levels will then again begin to rise and the entire cycle is repeated. A typical oestrus cycle lasts 21 days and consists of approximately 5 days of oestrous and 16 days of dioestrous.Mares are seasonally polyestrus with a breeding season in spring and summer and having a period during the year when they are sexually inactive. This is called anoestrous and coincides with winters shorter daylight length and lowered plain of nutrition. The commencement of the breeding season is stimulated by the environmental changes; lengthening daylight hours (photoperiod) the ending of winter and beginning spring with better pasture growth and quality, and a rising plain in nutrition. Environmental changes at both ends of the breeding season trigger hormonal responses. Specifically, the hypothalamus in the brain releases Gonadotrophin Releasing Hormone (GnRH) which in turn initiates hormone release from the pituitary gland. These hormones drive all the activities of the reproductive tract. The induction of estrus in mares is facilitated not only by endogenous and environmental factors, but also by exogenous factors and stallion stimulation by odour, sight, sound or touch. The complete natural stimulus is evidently of a Gestalt nature with olfactory, ocular, auditory and tactile stimuli being supplied by association with an active stallion. The phenomenon has been termed biostimulation and is especially effective during the transition from non-breeding season to breeding season.
Physiological changes in the mare include;
Proestrus The period during which the follicle is enlarging, concurrently there is an increase in the growth cells and cilia lining the oviduct, in the blood supply to the uterine lining (endometrium) and in the amount of mucus produced in the vagina. Oestrogen levels are increasing and the corpus luteum from the previous cycle is rapidly getting smaller. Oestrous The Pineal gland is responsible for the synthesis of melatonin and effects the development of the gonads, changing the amount of hormone secreted with variations in daylight length, affecting the mare in spring as oestrus activity begins.The oestrus period, during which the mare is receptive to the stallion and will stand to be mounted (Lasts approximately five/ six days) the uterus is contracted, the cervix is dilated and drops to the pelvic floor, and the mucus in the vagina is copious. Ovulation or release of the ovum occurs soon after the period of oestrus. Diestrus A period of approximately 16 days, during which the corpus luteum is developing and producing progesterone. This hormone brings about what might be described as a return to the status quo. The oestrogen levels drop rapidly and the uterus becomes soft and relaxed.
Anoestrus Absence of oestrus .Anestrus normally occurs, of course, if the mare is in foal or during the non breeding season. A seasonal period of sexual inactivity usually present in mares over the winter period with little uterine or ovarian activity taking place. The reproductive system shuts down and has a dormant cycle.
Behavioural changes in the mare include Oestrous.
During the oestrus period the mares behaviour changes she maybe irritable or sluggish and not perform as well as usual, squealing or kicking out if touched .The mare is ready to mate and will seek out and accept the stallion, she will show signs of oestrus, holding her tail up, stalling –frequent urinations, winking of the clitoris and a straddling posture. Her usual routines of behaviour are disturbed during overt estrus and typically there is a reduction in ingestive and resting behaviour, while locomotor, investigative and vocal behaviour is increased. The hormone responsible for this behaviour is Oestrogen from the Graafian follicle that are circulating through the blood stream, changing the behaviour of the mare and showing physical signs that the mare is in season.Oxytocin is another hormone present at the time of oestrus and is responsible for the uterine contractions that aid in the sperm transportation to the egg.Diestrus During diestrus the mare is uninterested and non receptive to the stallion and displays this to him by laying back the ears, switching the tail, biting, striking, kicking aggressively with general attempts to get away from the stallion.
The hormone responsible for this diestrus behaviour is progesterone being produced by the developing corpus luteum.
ReproductiveSystem The reproductive system changes during oestrus to facilitate pregnancy by relaxing and dilation of the cervix and lowering to the pelvic floor. There is a greater increase of blood engorgement to the mucus membranes giving a richer pink colour and the vulva becomes suppler. The cellular lining of the uterus thickens to prepare it for attachment of the fertilised ovum and mucus in the vagina is copious. Capillary action and muscular contractions in the uterus and oviducts help to transport spermatozoa through the genital tract quite rapidly. The mare’s temperature is slightly elevated.During diestrus the cervix again tightens and closes to guard against infection and vaginal mucus decreases again. The vulva and the mare’s temperature returns to normal.
Bibliography From Breeding to Weaning. 1999. Dwight G. Bennett, D.V.M., Ph.D. Keeping Livestock Healthy. 1994. N. Bruce Haynes, D.V.M The Behaviour of the Horse. 1997. Andrew F. Fraser, Professor of Veterinary SurgeryBlacks Veterinary Dictionary.1988 A & C BlackThe complete Equine Veterinary Manual. Tony Pavord BVSc MRCVS & Marcy Pavord. TAFE notes 2004
TAFE notes
Keeping livestock Healthy
Keeping Livestock Healthy
TAFE notes
Keeping Livestock Healthy
Complete Equine Veterinary Manual
Keeping Livestock Healthy
TAFE notes
The Behaviour of Horses
Keeping Livestock Healthy
Keeping Livestock Healthy
Keeping Livestock Healthy
The Behaviour of Horses
Blacks Veterinary Dictionary
TAFE notes
From Breeding to Weaning
From Breeding to Weaning
Keeping Livestock Healthy
The Behaviour of Horses ,Andrew F. Fraser
The Behaviour of Horses ,Andrew F. Fraser
The Normal Birth
During the birth, there are three distinct stages of the delivery of the foal.
First StageThe first stage of birth is very much like colic. The uterus of the mare starts to make preliminary, weak contractions. She will be generally uncomfortable ,may be anxious and begin sweating, showing signs of pain such as, pawing at the ground, looking around at her flanks,(pictured) flehmen posture, lifting her hind leg ,tail raised, and may repeatedly lay down and get up. The signs appear in increasingly intense phases, between which the mare may rest or eat. The muscles in the uterus wall bear down on the foal in waves passing towards the cervix, which dilates. The mare may pass frequent small amounts of urine and faeces. The fetal legs and head are propelled into the birth canal, flexing and extending, then the fore body twists into the dorsal position. This change in position places pressure on the cervix area and may force the outer fetal membranes; the chorion, into the vagina, which is sometimes seen protruding from the vulva and resembles a thick white balloon. This stage may last several minutes to several hours; this can also occur hours, days or weeks before foaling and be repeated several times in preparation of the birth. Finally the chorionic fluid is released through the birth canal and actually helps to lubricate it. It is referred to as the mare’s water breaking.
The Second StageAfter the water breaks, the second stage of foaling begins .The mare begins pushing her foal out, and the contractions of the abdomen becomes more obvious .The mare generally spends most of the second stage lying on her side, although she typically will get up and move around once or twice. When the mare strains, all four feet might come of the ground. The amnion then appears at the vulva followed by a foot, visible through the transparent amnion, then a second foot and the muzzle of the foal. With a few more strong contractions the front legs head and shoulders of the foal pass through the vulva. At this stage the movements of the foal usually break the membranes, if not it should be ruptured to allow the foal to breath. The hips and hindquarters are usually delivered quickly and easily with one final effort completing the second stage of foaling.The delivery is usually complete within 15 to 20 minutes after the second stage begins.
Third StageThe final stage of the birth is the passing of the afterbirth. The mare may show some signs of straining to pass the inside out placenta approximately one to six hours after the foal. The mares pituitary gland releases oxytocin; which is associated with the passing of the afterbirth, and causes the let down of milk for the new born foal to suckle.
Post Foaling careIn the first twelve hours after birth the mare and foal are observed to guard against any problems.The foal is watched closely to ensure all is well, particularly the removal of any membranes from the mouth and nasal area to enable him to breath freely, and if any are remaining should be immediately removed. The umbilical cord should be allowed to separate itself and then be treated by immersion in iodine, or chlorhexidine solution to disinfect the stump to prevent introduction of infection to the foal. The foal must pass meconium, which is a dark rubbery type of dung collected in the rectum, colon and cecum during its time in the womb. Foals often have a problem passing meconium, particularly colts. Studs now routinely give enemas to all new born foals ensuring the easy passage of meconium.
A TAT (tetanus anti toxoid) injection is also given immediately to the foal as a standard procedure. These three things are done to the foal even before he can stand, giving him the best possible start to life.The mare is checked for any tear to her vulva, and attended to if necessary. She is then totally washed down with a mild antiseptic solution, to cover any area the foal may touch when seeking out the teats ,particularly the mammary glands this is a precautionary procedure to prevent the ingestion of any germs to the new born’s delicate immune system.
A sample of the colostrum is taken to test to ensure suitable high levels (greater than 20) of antibodies in the colostrum for the new born. If levels are too low, a substitute from the colostrum bank can be fed to the foal.By now the foal is actively searching for the teat to have his first drink, it is advisable to watch and ascertain that the foal is indeed suckling well, and the mare has bonded with the foal and is allowing the foal to suckle. It is of paramount importance he receive this first milk, colostrum, high in antibodies.Dr John Madigan at the University of California at Davis, an expert in neonatology, suggests that prior to the ingestion of milk, the intestine of a new born foal is an open door for harmful bacteria to enter the blood stream. In addition to providing antibodies to protect the foal against disease, the colostrum closes that door so micro-organisms can no longer enter at will. During the first few hours the foal should suckle frequently and vigorously to get as much colostrum as possible, as after 12 hours, the mare’s supply of colostrum is mostly depleted, and the foal’s intestine is no longer capable of absorbing many antibodies. Suckling refers to the behaviour of the dam while feeding the young foal. Since the mares mammary gland is not very accessible the foal is required to extend and rotate it’s head and neck while retaining it’s “parallel and opposite” position with the mare. To facilitate this mare has a nursing posture in which she flexes her hind limb on the opposite side to the foal. The effect of this is to tilt her pelvis slightly in a way that the udder is directed at the foal as it sucks. It appears that the udder tilting coincides with the milk letdown.
Information RecordingThe information regarding the birth of the foal should be recorded for future reference and should include; Attendants name, mares I.D. name and brands, Time water breaks, time and date of birth.Placenta time delivered, condition and weight.Sex of the foal, colour and description including white markings.Sir of the foal.Time stood, suckled, colostrum level reading .Immunoglobulin G test (IgG) Meconium passed.Any abnormalities.Any other relevant comments, regarding the birth and bonding between mare and foal. General HealthAs often as possible observe the interactions of the mare and foal, the foals level of alertness, movement, and general conformation and the well being of both.The mare should be offered plenty of fresh water, bran mashes, hay or green foods three times a day, for the first couple of days then gradually increase back to her regular diet.Both need to be monitored for the seven days to alleviate any problems.Such as;Endometritis in the mare will be evident by a vulval discharge and needs vet attention to swab and give appropriate treatment.Mastitis evident by 47swelling, heat and pain of the udder, vet treatment will be necessary.
Diarrhoea, even a mild case in any foal can quickly become severe and lead to irreversible dehydration in neonates.
Milk Reflux, if milk comes out a foal’s nose during or after suckling he should be examined. Perhaps it could be nothing more than a greedy eater, but it could also be a sign of a severe problem, such as a cleft palate.
Umbilical cord within 24 hours after birth the umbilical remnant appears as a dried stump and in most cases falls off at about 1 to 2 weeks .A sign the foal needs veterinary assistance is the dripping of urine from the stump of the umbilical cord. In addition to blood vessels the cord contains the urachus, which, during foetal life, carries the foal’s urine to the placenta. At birth, the urachus should close. However occasionally the urachus fails to close or reopens and drips urine after the foal is born. This is referred to as a patent urachus. In many cases it will seal off with no treatment; however it may indicate all is not right with the foal. Sometimes the foal isn’t sick because his urachus is patent: his urachus is patent because he is sick. He should be examined by a Veterinarian to determine if there is a deeper problem.
Worming The internal parasite of most concern to neonates is the large round worm Parascaris equorum. Foals are highly susceptible to this parasite, which grows rapidly and can rupture a foal’s small intestine. Treatment is recommended at one and two months of age. By the time the foal is four months of age and joins a regular herd a programme for control of strongyles and other internal parasites should be implemented.
BibliographyFrom Breeding to Weaning .1999 .Dwight G. Bennett, D.V.M., Ph.D.TAFE Notes 2004The Behaviour of the Horse.1997. Andrew F. FraserThe Horse the complete guide to horse breeds and breeding.1986. Jane KiddGlenlogan Stud work experience 2004
From Breeding to Weaning.
The Behaviour of the Horse
The behaviour of the Horse
My Photos from Glenlogan Stud
The Behaviour of the Horse
Effects of Shoeing
“In his natural environment, on soft grassy plains, the horse’s foot serves him well .It grows sufficiently to replace horn worn down by daily wear and tear and provides enough grip for him to move about quite freely at all his natural paces. When the domesticated horse is trained as a riding mount or as a work, draught horse, he is subjected to unnatural stresses and strains associated with working , man compounds these problems by applying shoes.” Says, Monty Mortimer. It is not natural for a horse to wear shoes, but when man started using horses its feet began to wear away quicker than the horn could grow, making shoeing, for protective measures necessary. Shoeing a horse so his feet are disturbed as little as possible is a great art. If too much horn is removed to make the hoof fit the shoe instead of the shoe fit the hoof ,the weight bearing surface will be disturbed and change ,it also changes if the hoof is allowed to grow to long ,increasing the angulation of the joints and putting more strain on them. Dr. Hiltrud Strasser from A Lifetime of Soundness, states “Normal movement of the unshod horse wears down the lateral walls, heels and toes of the hoof naturally, this is not possible if the hoof is shod…and the hoof still grows while the shoe is on, contracting the foot and creating unnatural angles in the foot.”Healthy hooves of wild horses demonstrate 30 degrees angle at the hairline with ground parallel coffin bones and low heels .Coffin bone measurements show a consistent 45 degree angle on the front surface of the fore foot coffin bone and 55 degree angle on the front surface of the hind foot coffin bone.
(Demonstrated in the photos by Dr Strasser and Sabine Kells)
Below Left; Front hoof with 30 degree hairline and 45 degree toe angle. Above Right; Hind hoof with 30 degree hairline and 55 degree toe angle.Photos .Dr Strasser and Sabine KellsSolar view of uncontracted hoof.
The weight bearing points of the correctly shortened heels lie outside a line from the frog apex to the outer curve of the bulb, the properly trimmed bars also lie along this line.Photo. Dr Strasser and Sabine KellsHoof Mechanism - Above: Rear view of a hoof on a glass plate. Non-weight bearing (left), weight bearing (right). The healthy hoof expands upon weight bearing. The alternation of expanded hoof form on weight bearing to narrowed hoof form during the flight phase of the hoof (“hoof mechanism”) constitutes the pumping mechanism that aids the circulatory system and the heart, as well as transforming 60-80% of impact forces in a biological shock absorption system; this can only function properly with correct hoof shape. Photos .Dr. Strasser and Sabine Kells. The shape of the natural unshod hoof has passive and active wear areas with a large frog active upon weight bearing, a straight angle of hoof growth with undistorted hairline, short toes approx. 3”- 3. ½” and low heels of approx. ½” -1”.Soles and bars are naturally worn down through contact with terrain.The shape of the shod hoof consists of a passive narrow frog as only the shoe is active preventing the frog from contact with the earth, longer toes and higher heels. The soles are more scooped out by the farrier.
With the addition of shoes to horses hooves, ·
The walls cannot wear and maintain normal length and shape , additionally, an incorrect trim cant be worn away and added unnatural stresses on the hoof as walls get too long.· The Hoof mechanism and the circulatory pump in the foot is impaired as the feet of all equine act as miniature blood pumps assisting the hearts circulation through the establishment of Hoof mechanism, which is the repeated process of the weight bearing foot descending so the sole flattens as the hoof walls expand, allowing the 3rd phalanx to descend and the solar corium to fill with blood. The blood is then expressed upward when the foot is non weight bearing. Shoes inhibit and even prevent this important process occurring naturally, resulting in poor circulation, causing brittle and poor horn growth, no feeling and cold feet. With growing hoof wall restricted by shoes, the only direction things can go is up. High solar vaults begin to pinch the solar corium against the 3rd phalanx .The bars are forced upward against the deep flexor tendon and the navicular bone, bruising the coronary corium. Shoes can cause bruising of the navicular area and contraction of the heel.· There will be restricted blood circulation causing insufficient frog growth and natural desiccation of the frog from microbes and bacteria occur at a greater rate than the impaired growth causing thrush.· The vibrations from shoes destroy hoof walls and damages living tissue ,according to studies by Luca Bein ,showing that vibrations at 800 Hz on living tissue destroys the capillaries at the end of blood vessels. The vibrations of shoes are similar and destroy the solar corium.· A horse will lose 70 to 80% of natural shock absorption, and movement of the sole, creating incredible hammering on the bones and joints .A shod horse walking has three times the impact of an unshod horse trotting.· The horse can no longer break over naturally, resulting in inflammation of the corium and the lateral cartilage, tendons and ligaments and associated joints are affected on break over as when the shod horse tries to sharply turn on soft ground only to have the shoes dig into the ground, because of the added traction he stumbles and trips because he can no longer feel the ground.· Metal shoes do not give the amount of traction on slippery ground, pavement or rocks as unshod hooves. A natural barefoot uses the skid break action of the bars, suction- cup effect upon weight bearing, and the ability to “feel” the ground as an all- terrain tool.· The added weight of shoes (800g) is enough to throw the natural centrifugal forces out of sync and cause tearing of ligaments, tendons, and cartilage. Over time shod horses develop combinations of several kinds of contractions including contractions of the sole, heel, bulbs, coronet and bars; these deform the foot and eventually cause pain in the hoof. All affected by the incorrect shoeing methods of poor farriery workmanship due to a lack of enforced standards of the farrier industry. There are many poor examples of shoeing due to ignorance, neglect all exasperating the problems shoeing already causes. · The hoof grows at a rate of about 6mm per month, taking some nine months to grow from coronary band at the top to the toe at the bottom.· Nails destroy the hoof walls through vibration. They introduce infection via bacteria microbes and ammonia; they damage the corium, dry out the hoof wall and weaken the hoof wall. The nails being metal conduct heat and cold, so on a very cold day the nails conduct cold into the core of the hoof, lowering its temperature .The natural hoof insulates against the cold. · As the holes in the hooves left from nails don’t heal up, they leave the hoof venerable to bacteria as well as temperature extremes .Nail holes in the hooves affect the horn buy exposing this protective surface resulting in the horn becoming brittle. If a nail is driven in too high it will damage the sensitive laminae, may cause bruising and set up inflammation.· The contracting effect of the shoes increases day by day, since the hoof grows continually, not straight down but in a conical shape. The hoof grows in width, but the shoe dose not: after a month, the hoof grew by one centimetre, in length and in width: with a shoe, only in length, forcing a constriction in the corium. Worldwide Awareness of the effects of shoeing has now prompted horsemen to rethink the standard practice of shoeing, because of various sources of research it has been found1. Shoeing causes the hoof to become contracted.2. Shoeing causes a deviance of the normal laminae structure.3. The impact forces with each shod step are much greater, and the vibration of the shoe is damaging.4. The circulation of blood is decreased through shoeing.5. The side walls, at the widest part of the hoof, have to be able to move outward. All of these are Veterinary professionals.The effects of shoeing on the basic biomechanical function of the hoof and lower limb of the horse, in my opinion, both before and after researching the subject are mostly detrimental to the horse. However there are circumstances when having the horse shod is a necessary factor, such as a sporting horse, eg racing or for remedial gain to redress damage to hooves.According to Monty Mortimer “Consideration must be given to the breed of horse, the condition of the hoof ,the health of the horse, the comparison between the stabling environment and the terrain of competition.”
BIBLIOGRAPHY
The internet
YvonneWelz2004
Dr Hiltrud Strasser and Sabine Kells
Lisa Ross Williams. Healthy hooves the natural way.
Bracy Clarke London Veterinary College
Bracy Clarke Scientist London Veterinary College
Dr. C.C. Pollit University of Queensland
The Integument
The integument is the skin, hair and hooves of the horse. It is the largest and one of the most fascinating organs in the horse’s body and it is the only organ you can actually see.The skin waterproofs, cushions and protects the rest of the body. It has many vital roles to play in the efficient functioning of the healthy horse. The most critical role is maintaining a barrier against innumerable infections and infestations; it helps the body retain its vital fluids, plays a crucial role in temperature control and houses the sensory nerves. The general functions of the skin are: Provide a protective barrier from trauma, sun, chemicals and infectionHair and hoof production, a very important structural componentTemperature regulationVitamin D productionProvision of shape form via elasticity of the skinSensory organs. On the surface, hair is the first part of the integument we see is Hair (discussed in detail)is produced from within the skin, originating in the subcutaneous layer. Hair consists of a root, embedded in the skin, and a shaft, projecting from the skin surface. The root ends in a soft whitish enlargement, the hair bulb, which is lodged in an elongated pit in the skin called the follicle. Hair grows upward from the base of the follicle at a rate of about 1/3 millimetre a day. Blood vessels arranged in a small protrusion, known as a papilla, extend up in to the follicle and the root of the hair and nourish it. Attached to each follicle is a tiny muscle called the erector pili. This muscle is under the control of the autonomic nervous system and under certain conditions, such as cold, it contracts to stand on end to provide extra insulation for the horse. Individual hairs are composed of dead epithelial cells containing keratin arranged in columns around a central core. These cells also contain varying amount of the dark pigment melanin, which is responsible for the colour of hair, with age less pigment is deposited, so hairs tend to become white. Hair dose not grow continuously but has two phases and is produced in the follicle during the growing phase called Anagen, the follicle then passes into a resting phase and all growth stops, this is called Telogen, with time the follicle reverts back again to the Anagen phase and a new hair is formed .As the new hair emerges from within the follicle the old one is shed. The horse has two patterns of hair growth: body hair growth, which is synchronised resulting in seasonal shedding with increase day length or extra growth in winter and mane, and tail hair growth, which is not synchronised and consequently dose not produce seasonal shedding. Hair is lifeless.
The Layers of the Integument are; The Epidermis, The Dermis and The Subcutis The Epidermis is the most superficial layer of the skin, a transparent, thin top layer that covers the entire outside of the body. It provides the first barrier of protection from invading foreign substances. The principal cell is called a Keratinocyte, which contains a tough insoluble protein called keratin.The epidermis is subdivided into five layers or strata:The Stratum GerminativumThe SpinosumThe Stratum GranulosumThe Stratum LucidumThe Stratum Corneum The epidermis has no blood supply and therefore the cells appear dry and flat. The epidermis contains numerous nerve endings, detecting warmth, cold, light and touch. Hooves are also derived from the epidermis in a similar way as hair. Hoof grows at a rate of 6mm per month, growing slower in a cold environment as well as dry weather when adequate moisture is not present in the hoof wall. Also the chestnuts found on the inside of the front and rear legs of the horse are of a similar composition.
The base layer of the Epidermis is called the Stratum Germinativum.
This layer is three to five cells thick; cell mitosis occurs here, and it is also the layer in which pigment- producing cells called melanocytes are found. They produce the pigment melanin, which is responsible for absorbing the dangerous ultraviolet light .Sunlight stimulates the manufacture of melanin and leads to the production of vitamin D in the skin – essential for the absorption of calcium from the gut and the maintenance of bone density.The Stratum Spinosum is the next layer which is eight to ten cells thick and is and is made up of flattened cells with spiny projections. The Stratum Granulosum is three to five cells thick and it is here that keratin is produced a waxy substance that forms a tough surface layer in the outer most epithelial cells.The Stratum Lucidum a thin clear, keratin- rich layer three to four cells thick, which is the thickest on areas such as the dorsal trunk. The outer most layer is the horny layer the Stratum Corneum. Most of the cells in this layer being between twenty five to thirty cells thick are dead; it takes about two weeks for the cells to reach the surface, where they are sloughed off .Thus the skin is in a constant process of renewal. The Stratum Corneum is the main barrier to skin infection; if bacterium, virus or fungus manages to penetrate this layer, dermatitis may follow. The Dermis is the layer below the epidermis, and is the most important part of the skin It is essential for a rich and bright hair coat, and healthy skin. Assuming the important functions of thermoregulation by way of dilation and constriction of blood vessels to cool off or warm up the blood and affect the horse’s temperature according to climate and other influencing factors, exercise or illness.The Dermis has two zones a reticular layer and a papillary surface.The dermis layer is quite thick and is composed of a mass of interwoven collagenous fibres. The Dermis contains mostly fibroblasts which are responsible for secreting the collagen, elastin and ground substance that give the support and the elasticity to the skin.Also present are immune cells that are involved in defence against foreign invaders passing through the epidermis. It houses nerve endings for sensing touch, pain, pressure hot and cold .Nerve impulses travel to the brain via nerves and pathways in the spinal cord, alerting the brain of the sensation and allowing it to take appropriate action.In the Dermis are tiny sweat glands that secrete sweat, a salty watery fluid, as sweat evaporates it cools the body surface helping prevent overheating.Sebaceous glands open into the hair follicle to release sebum that lubricates and waterproofs the hair and skin, the combined secretions of the two glands provide a natural film that protects the skin from damage by water, chemicals and micro-organisms. Vascular network supply the avascular epidermis with nutrients and the white blood cells also help keep the skin clear of infection. Lymph veins are also located here, which is where the body’s immune system mounts the first defence against infection. A chemical gel, known as “ground substance” binds the dermis together, allowing for the passage of salts, nutrients and cells from dermal blood vessels into the epidermis. The subcutisThe subcutaneous layer beneath the dermis lies over skeletal muscles, and performs the function of feeding, excreting and heat exchange. This layer is composed of elastic and fibrous connective tissue known as adipose tissue. The panniculus muscle, the sheet of skeletal muscle that separates the skin from the rest of the body tissue, lies at the bottom of the subcutaneous layer. It is the muscle that twitches the skin to dislodge a fly and it generates heat by persistently contracting in a movement we call shivering.The mammary glands are modified sweat glands of the skin adapted for nourishing the foal. The eyes are also (excluding the retina) derived from the skin. A major health condition affecting the skin of the horse is caused by Dermatophytosis or Ring Worm. Two groups of fungi are responsible, Trichophyton and Microsporum.The signs include lesions that can appear anywhere but particularly sweat areas (that gives a good food source for the fungus) typically, small circular lesions progress to thick crusts and hair loss, lesions are not normally itchy.Treatment would include isolation of infected horse. Clip and wash the entire affected horse repeatedly with an anti-fungal preparation until the infection has resolved. Antibiotics can be administered. Dispose of all hair and crusts that may be removed and disinfect stables, all tack and rugs etc. Each horse should have its own tack and grooming equipment for prevention of spreading to unaffected horses.
Disease Control
Responsible management of a horse stud, most definitely includes monitoring of horses for any signs of disease. The introduction of any new horse to the stud is to be carefully monitored. It would be most wise to isolate the new horse, well away from other horses, in special isolation yards, for a period of time to be sure it has not introduced any disease to the already healthy stock. Viewing the horse’s vaccination and worming program with the owner and if unknown or unvaccinated the horse should be isolated and the updating or implementation of a program will ensure reduced risk of introduction of diseases. All vaccinations should be recorded (example next page).Prevention, by way of vaccinations, and parasitic anthelmintics, is the most effective measure in dealing with disease.Vaccinations are available to provide protection against;TetanusStrangles Equine influenzaEquine herpes virus (EHV, or Rhinopneumonitis)Equine viral arteritis (EVA) all of which are serious or fatal diseases.Horses should be routinely immunised against those diseases from which they are most at risk in the region where they live. Staff should be proficient in horse husbandry, especially disease management procedures, ensuring any suspect health problems are noticed and dealt with immediately. Specially allocated, isolation areas with yards and stables (run independently of the main stables) should be available to move sick animals away to promptly, from healthy stock. Infection symptoms and TPR , capillary refill ,mucous membrane colour and hydration test, should be taken and recorded to monitor the horse’s disease. One staff member is to deal with the infected horses, with strict hygiene measures used, especially washing hands and boots, thereby reducing possible spreading of the disease.With all disease cases the stable which contained the infected horse should be steam sterilised thoroughly covering all possibly surfaces and removal and destruction of bedding and not forgetting sterilisation, of equipment, rugs, tack etc. or paddocks rested for an indefinite period. Young stock on the property, being most susceptible, should be grouped together and offered the cleanest pastures to graze on reducing the risk of parasite infection. Implementing all procedures of parasite management relating to my Assignment 1 of horse Health & 1st Aid to this assignment ,rotation of paddocks and wormers etc. High risk horses for example, pregnant mare in last trimester, mares with foals at foot, weanlings and yearlings are most at risk to disease, as their immunity is lowered or reduced and haven’t built up a high enough resistance to diseases ,again immunisation should be current. These horses should be paddocked together within a similar group. Stallions also are at risk, because a temperature reduces the viability of the sperm and therefore rendering him useless for a period of time.
Tetanus protection is absolutely essential for all horses, it occurs when a wound becomes infected with bacterial spores of Clostridium tetani. These spores germinate multiply and produce a very powerful, toxic poison which affects the nerves and leads to spasms of muscles. Closing of the third eye lid, ears pricked, dock raised and progressive paralysis leading to death by exhaustion and inability to breath. Tetanus is highly fatal and contagious. Some cases of tetanus occur from wounds so small they are not noticed. Any case should be isolated well away from healthy stock .A Vet will be required to confirm the disease and attend an administer assistance to the horse and advise of nursing methods. He will also notify the disease control authorities.For all horses and foals ,three months and older, the primary vaccination course consists of two injections ,four weeks apart, followed up by a booster one year later. Boosters are recommended every three to five years thereafter.
Strangles is caused by a bacterium, streptococcus equi, which is extremely contagious , that induces acute respiratory disease, the first signs are increasing depression, high temperature over 39oC, cough and a mucoid nasal discharge rapidly becomes mucopurulent, then purulent. Strangles is spread by direct contact with the pus and nasal discharge. The glands behind the ears & in the angle of the jaw& between the arms of the lower jaw become swollen and tender and the horse will stand with head outstretched and rigid. The horse has loss of appetite with an inability to swallow due to pain of swollen glands. Glands continue to swell and when abscess burst, releasing quantities of pus most cases rapidly improve. Very young or old horses are at greater risk with complications often following, causing abscess formation in the lungs or brain or lymph nodes of the abdomen. Isolation of effected horse is necessary to prevent spreading. The Vet will be required to attend to the horse and confirm the disease and advise of nursing methods. He will also notify the disease control authorities.Vaccination is available and is administered as follows;First vaccine, second vaccine, two weeks later, third vaccine, two weeks later then First booster twelve months after, then annually .It is also available as a 2in1 with tetanus.
SalmonellosisInfection is by Salmonella typhimurium .Stress is also involved in the development of the disease and diarrhoea is common following the stress of surgery or after a long journey. The bacteria are capable of living in the gut of an apparently normal horse and are excreted in the faeces of these horses, companion horse become infected through eating contaminated feed or bedding. Therefore isolation is necessary. Initially acute diarrhoea, colic and discomfort a fever 39oC+, heart and respiratory rate rises, the horse becoming weak and very depressed; the release of endotoxins into the system through damaged mucosa causing profound shock, septicaemia might also develop.A vet will be required promptly to administer intravenous fluids and other appropriate medications and advise of nursing methods and attention to hygiene.
EHV Rhinopneumonitis It is a herpes virus (types EHV 1 & EHV 4) and cause respiratory disease, abortion, and neurological problems in horses.EHV3 is associated with the venereal disease known as coital exanthema. A high temperature and slight clear nasal discharge with head and neck glands sometimes becoming enlarged .The clear discharge becomes mucopurulent, thick grey /yellow and smelly as secondary infection takes place. The virus is spread and is present in nasal exudates, expectora, blood and faeces in affected animals during the febrile stage. The virus is also abundant in fetal membranes, fluids and all tissue of the aborted fetus affected with EHV. Close contact between individuals or contact with fresh secretions is usually necessary for transmission of the virus. , the only way of controlling the spreading is by prompt isolation.Vaccinations are available called Rhinomune and Duvaxyn EHV1, 4, but with a short coverage period and shots must be given every 3-6 months. It dose prevent the virus from multiplying.Veterinary assistance will be required and drugs administered.
Equine influenza A severe acute respiratory disease .The virus gains entry through the nasal mucosa and attacks the lining of the respiratory tract causing damage and eventual death of large areas of the mucosa. The older horse developing a high temperature, a clear nasal discharge and a cough and in the absence of secondary infection, clear up in a week or so although it takes about three weeks for the damaged mucosa to repair. The heart muscle and liver cells can also be damaged by the virus infection. Young animals become very ill and sometimes die, although death is more usually due to pneumonia caused by secondary infection. Good ventilation in stable situation is necessary.Veterinary assistance may be required especially is a secondary infection is evident.Vaccinations are available with an immunity period of 10-15 months. In conclusion any major disease outbreak is notifiable to the Department of Agriculture, which the attending vet will be bound by law to notify. The horse enterprise will be put under quarantine, no horses allowed to leave or enter the property until the disease threat has passed and the property is given the all clear from The Department of Agriculture.The best possible way to prevent spreading of disease when an out break has happened is by isolating the sick horse and the implementation of strict hygiene methods as I’ve discussed previously.
Bibliography Blacks Veterinary Dictionary Geoffrey P. West MRCVS 1985 The complete Equine Veterinary ManualTony & Marcy Pavord The Horses Health A to Z Peter D Rossdale & Susan m Wreford 1998 Keeping Livestock HealthyN. Bruce Haynes D.V.M
Parasite Control
Good grassland management is the first stage in controlling horse parasites, as worm larvae are repeatedly ingested by the horse grazing on infected grass. This can be achieved in several ways. Rotating paddocks (if available) to rest the grass by allowing a recommended minimum two month spell. Rotational grazing with cattle or sheep, which are susceptible to different parasites, helps to clear the ground by breaking the life cycle of parasites that affect the horse. Regularly, and at best, daily, collection of manure. (Thus removing any possible reinfection from ingestion).The collected manure can be removed to a remote spot away from grazing pasture, and allowed to compost. Free range chickens are an asset, as they scratch through the manure, spreading it about they expose any worm eggs to the destructive effects of the sunlight. Supplying feed bins and racks to keep feed and hay off the ground is a good practice. Water troughs should be high enough to be protected from fecal contamination and regularly cleaned along with excellent hygiene and sanitation of yards and stables. The practice of ploughing and reseeding of pastures, harrowing, or slashing when hot and dry, or dry and frosty, thereby keeping grass short ,so there is no tall grass to trap moisture favouring egg development. Being aware of stock numbers is important, so pastures are not overstocked. Removal of any bot eggs with a knife or their destruction by applying kerosene will prevent the eggs being ingested by the horse, thus preventing internal infection. Regularly washing of the anus, and or the application of the chosen anthelmintic to remove any pin worm eggs is also a beneficial. All these methods are really methods of sanitation, which is the key to control of internal parasites. All these combined, will all contribute to reduce the parasite factor on a horse enterprise
Internal Parasites Roundworm: Parascaris equorum
A large, white worm <50cm long. Adult worms lay large numbers of infective eggs which are climatically resistant.Larvae are ingested through grazing, bedding or water.They penetrate the intestinal wall and migrate via the blood stream through the liver staying a few days before migrating to the lungs where they move into the alveoli, causing copious nasal discharge and coughing. They are then coughed up and re-swallowed and then mature in the small intestines. The larvae develop in the fore part of the small intestines for 8-10 weeks until reaching maturity. They then begin to lay eggs which pass into the faeces and onto the pasture. Signs are poor appetite, rough coat, and pot belly, intermittent and scouring coughing when the larvae migrate through the lungs.
Dictyocaulus arnfieldiThe normal host of the lungworm is the donkey .The lungworm lay large numbers of eggs which contaminate the pasture for many years, similarly the eggs are ingested while grazing, hatch out in the intestine and then the larvae migrate to the lungs- but remain here as immature worms, unable to complete their life cycle, but quite able to cause disease.Signs include a chronic, irritating cough that alters very little, with no nasal discharge and little effect on appetite or condition.
Threadworm: Strongyloides westeriA very small, fine, worm commonly found in the small intestine of foals, and can be responsible for diarrhoea (in very young foals) Becoming infected by L3 larvae present in the mare’s udder and excreted in the milk. It can infect the foal via the milk as soon as 4 days from birth, and (develop full patency during the next two weeks). They can also be contracted through the skin by direct contact with the mare .The inhibited larvae lay dormant in the mares muscle or udder, when in late pregnancy the “immuno suppressed” –reactivates the larvae, passing on to the foal. It is the presence of these worms that cause diarrhoea ,not the foal heat of the mare. Adults develop an immunity to the worms. Signs can cause diarrhoea in young foals.
Large Strongyles: (3 Types of) the most common and dangerous
Strongylus vulgarisThe adult worm lives in the intestine, and here the female lays eggs which pass out to the pasture. In 1-2 weeks larvae hatch and infective worm larvae are picked up while grazing, entering the digestive system they penetrate the intestinal wall and migrate to small blood vessels that supply the gut. In the large Mesenteric Artery they grow for several months buried in the arterial wall (undergoing further development) then migrate again to the large intestine where they burrow into the wall and hibernate for a further six weeks. When they emerge as adults they start feeding on the lining of the large gut, where they damage considerable mucosa and blood vessels. Signs spasmodic colic, rapid weight loss, depression and fever and in large numbers chronic anaemia and with the damage done to intestinal mucosa, upset the body’s fluid balance, causing diarrhoea.
Large and small Strongyles Small Strongyles: 40-50 types
Cyathostomes
Eggs are laid throughout the year, hatching in faecal matter, and in warm, wet conditions spread to adjacent foliage, reaching infective stage within a week. Cold dry weather slows down this stage .Once ingested they burrow into the wall of the intestine and undergo further development for a variable period. Then they emerge from their cysts and gradually mature into adults in the lumen of the large intestine.Signs can cause severe diarrhoea and large infestations may cause colic. Immature stages form cysts in the gut wall and when they hatch out in large numbers the result is severe scouring.
Pinworms: Oxyuris Equi A Large intestinal worm the adult females migrate to the anus to lay their eggs in masses and their activity can cause intense irritation under the tail, shown by the rubbing their backside against a tree or post. Signs obvious rubbing, resulting pruritus can lead to emaciation in severe cases, unsightly bare patches on the tail and hindquarters.
Bots: Gasterophilus Bots are larval (maggot & cocoon) stages of bot flies. Large, noisy, hovering, bumble bee type, adult flies lay their eggs on the hair of the forelegs and abdomen of the horse. The eggs are tiny yellow / orange coloured and cemented tightly to the hair, remaining there until the warmth and stimulation of the horse licking, grooming action they hatch. The larvae ride on the tongue and embed them selves in the mucosal lining of the mouth. After a period they migrate to the stomach remaining here for up to ten months then passing out in the faeces onto the pasture. The adult flies hatch out late in spring ready to renew the cycle.Signs Eggs present on hair. External Parasites
Ringworm: Dermatophytosis
two types Trichophyton and MicrosporonRound crusty scab appears which multiplies & develops to cover a large area .Caused by a fungal invasion of the skin cells and hair follicles (no worm involved)(Unable to research life cycle)Signs Development of “ring” lesion on the skin.
Lice: Biting louse Damalina and Sucking louse Haematopinus
Lice are small wingless parasites which live on the skin in the coat of the horse. Eggs are laid on the body, cemented to the hair There is no pupal stage although several moults take place and hatch in 20 days, the young louse is identical except in size to adult louse. Sucking lice are found at the base of the mane and tail and biting lice are commonly on the lower parts of the body .They are killed by dry heat .Signs poorness of condition ,itching and loss of hair.
Control Measures
A worming programme should also be stragically carried out in conjunction with the good practices of pasture management to minimise the infestation on the ground. Rotating (between the 3 drug groups) of wormers every 12-18 months to avoid resistance. A stock management book recording all horses, should contain worming programme information regarding wormer type given, dose rate relating to weight (accurately assessed by weight tape or body weight formulae) and date, it is important to be kept up to date. With the administration of a wormer the horse is best confined to a yard for a period of 24-48 this way you can visually see any worms in the manure and it is easy to dispose of the contaminated manure. Faecal egg count is also a good tool and is widely used in the livestock industry, to monitor stock for internal parasites; it gives an indication of pasture contamination.
Herbs are another method used in the control of worms; traditionally there are a number of herbs with worming properties. These include monthly treatments of: Wormwood is used for the treatment of threadworms and roundworms. Garlic is used for the treatment of roundworms, pinworms, tapeworms and hookworms. Aloes are for all other types of worms. All are extremely helpful in assisting the horse to repel external parasites such as ticks.
I myself do use natural remedies daily mixed in feed rations such as,
copper sulphate- sulphur - apple cider vinegar - garlic and seaweed meal.
BibliographyVictoria Ferguson 2004Equine Herbalist Complete Equine Veterinary ManualTony Pavord BVSc, MRCVS& Marcy Pavord Blacks Veterinary DictionaryGeoffrey P. West MRCVS 1985 The Horses Health A to ZPeter D. Rosedale & Susan M. Wreford 1993 TAFE notes
Ancare Equine Health Care Technical Assistance 2004
Endurance Riding
I have chosen Endurance riding (long distance) as an Equine sport that interests me. Endurance rides cover a course of between 25-165 km + in a day or up to 480 km in five days in 96 km stages through the country side. Stringent veterinary checks to monitor the horse’s health and fitness take place at intervals over the entire course and entry is limited by qualifying rides, which are universally adopted. The ideal conformation of the endurance horse would include; A flowing joint of the neck and head with a good length of rein Wide and deep girth with well developed rib cage for heart and lung capacity Ample width and depth of chest Good sloping well muscled shoulders Forelegs well muscled, squarely set, & fairly straight from top of leg to the hoof Visibly defined elbows standing clear of the ribs Strong back with good length proportional to the body Well muscled, short loins Well developed quarters, strong gaskins and strong clean hocks Very straight cannons, clean fetlocks and correctly angled pasterns and Good feet. The Arabian horse breed truly sparkles in endurance riding, having been bred for centuries to travel through the harsh desert terrain for days on end, the Arabian was built for endurance. This Arabian Stallion exhibits good all round conformation. He has the required flowing join of the head to neck, which is strong and flexible and has a good length of rein, this is important to achieve lightness and balance with no restriction of movement.If incorrectly attached, the horse lacks suppleness of movement and this would unbalance the whole horse with regards to equilibrium.The position of the head at the neck and throatlatch should be well angled, with a good width between the throatlatch and lower jaw so there is no breathing restrictions.As evident in the picture below.
The girth and ribs should be amply wide and deep for provision of the heart and lung capacity (as below) If these are restricted the horse’s ability to cope with the extra cardiovascular and lung expansion, would make it physically impossible for the horse to cope. A horse with a good conformation will have a greater girth measurement than his height.His shoulders need to be well muscled with a forward 45-degree slant this gives the horse (as above) freedom of movement, allowing the horse to work to maximum capacity, and act as shock absorbers as the majority of weight is borne by the forehand therefore an undesirable, upright shoulder with a minimum of angulation between scapula and humerus, produces a shortened stride and is prone to jarring, so the limb is more predisposed to concussion related injuries. His chest needs to be reasonably broad and muscular as below, if the chest is narrow, there would be leg interference, and can indicate poor stamina and respiratory problems, and if to ample a rolling type of stride makes for an uncomfortable ride.
The forelegs need to be well muscled, set squarely and straight from the top of the leg through to the hoof as in figure 3 & 4Viewed from the front the forearm bone and the cannon bone, through to the hoof should be in a straight line, with the knee centred between.This is necessary so there is no leg interference during stride, such as brushing or plaiting. Any defects affect movements, leading to sore ligaments, swelling in joints and muscle tension through out the leg and chest area.The cannons need to be very straight with clearly defined tendons behind them and not off set, boots would be needed to support the area to help minimise any tendon strains. They should not have defects as in figure 1 ,2,5 & 6 because any deviation inwards or outwards of any of the bones or joints places increasing strain on muscles ,tendons and ligaments, sufficient to cause temporary or permanent damage.
The fetlock joint should be clean, not puffy or swollen such as windgalls shown here.
This type of injury is due to wear and tear and fetlock strain and would “vet out” an endurance horse. The Pasterns, ideally should have a 45 to 50 degrees angle (below right) the same angle as the shoulder blade and proportional to the rest of the leg, being neither too short (see below left) resulting in too much concussion and jarring of the leg structure from a choppy stride, or to long (see below left) resulting in ligament and tendon strains.
The elbows (Ulna) need to be well defined and stand clear of the rib cage obviously so not to interfere with the body of the horse.(as below)A strong back is essential for endurance riding as a saddle is used throughout the many hours of the ride, if it were if too long it could be subject to inflammation and strain and is also likely to have weaker loins and possible kidney problems therefore having a reduced weight carrying ability. The loins have the least structural support, so need to be well muscled. A short back from withers to croup restricts the action and, if disproportionately short can result in action faults or deviations and gives a “rough” ride. A strong back is evident on this horse. The quarters need to be well developed for athletic performance and need to be well muscled for propulsive, driving power. The horse needs to have good length of hindquarters to enable him to get his legs under his body for bigger movement and more power and if too short, the horse has a reduced length of stride.The Gaskin need to strong as it originates most of the muscle action needed for the hock and foot movements.
Excellent feet are essential. Well conformed and well balanced feet are vital for long term performance, and should be remembered that the balance of the foot be assessed in conjunction with the conformation of the limb above it ,and, taking into account the effects of the transference of bodyweight and forces of movement via the limb to the ground. Medial and lateral balance of the hoof should be clearly visible. Good farriery is a must as shown above. If the horse has badly conformed feet such as the broken hoof –pastern axis(shown below) tension is created both the tendons and ligaments .Tension on the digital flexor tendon over a long period of time can develop into pathological changes such as navicular disease, due to the increased pressure on both the navicular bursa and bone. One specific conformational fault of an endurance horse would be Ewe neck.This is when the neck appears to be set on upside down. This may be entirely due to poor conformation and or exaggerated by the hands of the rider .The neck should be bent at the poll (atlas) and any bend further down the neck (swan neck) is undesirable because it also restricts the neck from carrying out its correct function as a balancer and the higher than normal head carriage, makes for an uneasy, uncomfortable ride. The cervical bones of the neck do not form a straight line from the poll to the wither, but curve gently downwards and then turn upward again to join the body at the withers. If the horse is ewe necked or becomes ewe necked when ridden, it is the mastiodo humeralis muscle which is over developed. The muscles which should be developed to obtain correct head carriage are the splenis and the serratus Magnus. The rhomboideus is the crest which should be developed but not overly. The first two bones of the neck, the atlas and axis, often need chiropractic attention as does the point where the neck joins the withers. Acupuncture also may assist . The use of rings or martingale as a riding aid could assist with lowering of the head carriage by keeping the head low reducing muscle build up underneath. Alternately the horse and rider need to practice exercises and should perform work with long-low outline, correctly produced by riding the horse forward with a very light contact and keep him up on the bit with the legs, done on long straight lines with large half or quarter –circle corners and long changes of direction at a walk and rising trot .This is continued until the horse relaxes his frame into the position required and keeps a regular tempo. The ewe necked horse must carry out this type of exercise for many months.A second conformation fault, contracted heel due to poor conformation (upright pasterns) and can also be caused by incorrect shoeing. An upright pastern dose not absorbs concussion well giving a choppy stride with a jarring action and concussing the leg. If a result of poor shoeing it is easily corrected by changing to a more knowledgeable farrier who will remove the shoes, allow the toes to grow a little and cut back the heels to widen the hoof again. If congenital the farrier can still help but cannot be expected to alter drastically the conformation of the foot. The ideal conformation of the endurance horse as discussed above is very necessary to enable the horse to effectively compete at his optimum performance capabilities and facilitate him to complete the course in a fit and healthy state. It also makes a comfortable ride for the competitor. A horse with conformation faults has to work much harder and will usually “Vet out” of contention. As the stringent vet checks during the course will easily pick up any problems
Bibliography
The Arabian Horse History, Mystery and Magic By Thames and Hudson 1998 Encyclopaedia of the HorseDavid Broome CBE 1998 The Amateur Horseman Margaret Clarke 1988 Ultimate Horse Care complete veterinary guideJohn McEwen Bvet ,MED, MRCVS 2000 Horse Owners HandbookPenny Swift 2003 The new Encyclopaedia of the HorseDorling Kindersley 2000 Complete encyclopaedia of HorsesJosée Hermsen 1998 Equestrian Horse Care Essentials Magazine 2003 Tina HowlandEndurance Horse competitor and breeder Rocarnee Lodge Arabian Stud McKee’s Hill 2004
Stay Apparatus
“Horses can stand on their feet for long periods, without obvious stress, much longer than other domestic animals,” says Dr. Gerald Pijanowski, professor of morphology at the University Of Illinois College Of Veterinary Medicine at Urbana. ”This enables them to rest and doze and still be prepared to take flight in a second’s notice, if need be. If they were lying down when a predator arrived, the time taken to get to their feet and flee could cost them their lives.”This is all possible due to the “Locking” mechanism of the fore and hind limbs and is known as the Stay Apparatus.The term “stay apparatus” is applied to the arrangements of ligamentous tissue in the fore and hind limb muscles, which support the joints and so, diminish muscle fatigue. The efficient use of this apparatus is considered to help the horse stand for very long periods of time, without any obvious stress to the horse, for example, the London Horse Guards that stand in one spot for two hourly guard duties.The stay apparatus is a system of muscles, tendons and ligaments in the horse’s legs that work together with the suspensory apparatus to allow the horse to “lock” its leg joints with no muscular effort. This co-ordination stabilises the leg and allows the horse to sleep while standing up. Several features of the equine leg anatomy allow horses this advantage; They are; the front stay apparatus , hind Stay apparatus, reciprocal apparatus, and the locking mechanism of the stifle joint.
The Front Stay apparatus is composed of many of the ligaments and tendons of the fore-limb. Stabilisation of the fetlock is created by the flexor tendons, the sesamoidean ligaments and the suspensory ligaments. Extra strength is added to the deep digital tendon by the carpal check ligament. The flexor tendons support the fetlock from the back, and the suspensory ligament, front extensor tendons and the sesamoidean ligaments support the joint from the front, preventing flexion of the joint and collapsing of the leg. The carpus is stabilised by the radial check ligament and the configuration of the bones of the carpus. Minimal muscular activity is needed to hold tension on these ligaments and tendons. This allows the horse to balance its weight on its legs almost as if they were legs of a chair. The Hind Stay Apparatus is also composed of many tendons, ligaments and muscles, but the main component is the ability of two muscles, the Quadriceps Femoris and the Tensor Fasciae Latae, to pull the patella over the medial trochlear ridge (inside ridge) of the femur. This locks the stifle, and through the reciprocal apparatus of the hind leg, also ‘locks’ the hock and fetlock joints. The locking mechanism of the stifle and the reciprocal mechanism together, allow the horse to put weight on one hind limb at a time while it rests the other. The “locking mechanism” consists of the loop formed by the junction of two patellar ligaments with the patellar and the bony projection of the lower end of the femur. The patella is thus firmly secured and the joint is locked in an open or extended position. It can be unlocked quickly by reversing the motions that locked it. The reciprocal apparatus a peculiar modification to the hind limb of the horse, it consists of muscles on opposite sides of the tibia, which are largely and entirely tendinous. The muscle on the cranial surface is the fibularis tertius. It is attached proximally to the femur between the trochlea and the lateral condyle. Distally this tendinous structure bifurcates, both divisions inserting in the tarso-metatarsal region. The fibrous structure and attachments of the fibularis tertius muscle ensures that normally flexion of the stifle joint must be accompanied by flexion of the hock. When the patellar lock is activated, immobilising the stifle, and hock, all are fully locked only when the horse puts most of its weight on that limb. The other rests on the tip of the hoof. This posture can be recognised because the resting hip sags lower than the supporting one. No muscle activity is necessary for the joint to remain immobile. To release the mechanism, the weight is taken by the other limb and the quadriceps femoris muscles draw the patella proximally .It is then twisted slightly laterally and returned to the trochlear groove.. The tendinous tissue included in the “Stay Apparatus “of the hindlimb. The structures of the forelimb “Stay Apparatus” involved are: Biceps brachii tendons (both origin & insertion) Lacertus fibrosis tendon Radial carpal extensor tendon Common digital extensor tendon Serratus ventralis muscle (thoracic portion) Triceps muscle (long head) Superficial digital flexor tendon & superior check ligament Deep digital flexor tendon & inferior check ligament Suspensory ligament & its branches Distal, collateral and intersesamoidean ligaments Tendinous tissue included in the “Stay Apparatus” of the forelimbThe lacertus fibrosis is a long tendinous band running through the biceps brachii and the fascia (connective tissue) of the forearm. It ends by merging with the radial carpal extensor tendon. Its function is to assist the stay apparatus by stabilising the knee, keeping it from buckling forward. These structures work together to hold the legs in a normal standing position. For example, the serratus ventralis muscle supports the horse’s body weight, which would normally flex the shoulder; but the biceps brachii tendons and the triceps muscles prevent this action by extending it. The superficial digital flexor tendon and the Deep digital flexor tendon help by fixing the elbow joint .Of course ,the bones from the elbow to the fetlock are situated in a more-or-less straight line , so it takes very little effort (by the lacertus fibrosis) to stabilise them. The fetlock joint, through its distal sesamoidean ligaments , is under constant heavy strain created by the horse’s body weight. The suspensory ligaments and its branches, as part of the stay apparatus, hold it securely in the normal standing position.
Distal part of the limb showing the “Stay Apparatus” The “Stay Apparatus” which enables the horse to sleep while standing , is an important feature for the horse ,as its immense body weight dose not allow for lying down for any length of time on one side,(during this time the lower lung dose not function efficiently and muscles become cramped.) and so the horse has adapted well utilising the“Stay Apparatus”.
Bibliography
The Horses Health from A to Z Peter D. Rossdale & Susan M. Wreford1998
Ultimate Horse Care John McEwenB Vet Med MRCVS2000
Internet Research; Equine Research USA
Cold Blood
Warm Blood
Hot Blood
The Coldblood horse is a large bovine type horse (some pony breeds are included) originally breed in the colder climatic areas of the world in the Northern hemisphere where harsh cold temperatures prevail.Coldbloods range in size from 15hh to 17+hh as well as some pony breeds. Coldbloods are characterised by relatively short backs and limbs and rounded body. They are a heavy set, stronger breed, with a thick crest and substantial muscular short neck, running into deep oblique shoulders, which are wide enough to carry a collar for harness purposes. The head is large and broad, convex or straight profile face with large soft eyes and small ears. They have small and narrow nostrils and long air passages to warm cold air which could otherwise chill the lungs and heart. They have large hooves with feathers around the feet and have a thick mane and tail with a thick coat creating insulation from the colder climate. The quarters of this Coldblood horse are well rounded with very powerful and muscular legs. One type of Coldblood ,the Shire horse was breed principally in the UK. It descends from the English Great Horse of the Middle Ages, which inturn was derived from the heavy horses brought into England after the Norman Conquest. Those horses were descendants of the primitive, Coldblood Forest Horse. The big heavy draught horse did not appear in Britain until the end of the 16th century, when the Great Horse, no longer required to carry heavy knights in full armour, was used to haul heavy wagons, coaches, drays etc. where great pulling power is needed. The Coldblood was utilized as a “work horse” The conformation of its great size with a short thick neck, strong short legs and powerful quarters and shoulders gave the horse a slow but enduring power and stamina to do manual labor. The placid temperament also assists the horse by saving energy which conserves heat and insulating body fat. The passive, docile nature of the large Coldblooded horse is a great asset to man, because of the type of work asked of the horse eg: harness work. He is a reliable docile and gentle “Work Horse”. The Coldblood displays substance. Slow moving with a steady gait is typical of the Coldblood horse; he is not a quick and agile horse. The length of stride is enormous due to the largeness of his limbs and range of motion. The heavy boned skeletal system of the Coldbloods is reflected in the overall body weight of this type of horse averaging between 1000 and 500kgs depending on breed. The long bones of the body are found in the limbs, the cannon bone for instance is much denser and wider than in comparison to that of a hotblooded horses, finer cannon bones.(This is my assumption I was unable to find specific information through research) He has a massive muscular system to support his large body weight which provides him with the capability to perform heavy physical tasks.He has evolved with well developed slow twitch muscle fibres for enduring muscle lasting power, to be capable of the daily draught tasks asked of him. Some Coldblood horses are, Ardennais, Boulonnais, Percheron, Suffolk, Shire, Clydesdale, Brabant, Noriker, Dutch Draught and Friesian.
The Warmblood horse is a blending of the Coldblood, from cold, harsh climatic regions, and the Hotblood horse from hot, arid climatic regions. The term Warmblood usually indicates that the horse has some eastern blood in its pedigree.
The evolution of the Warmblood came about Two centuries ago when European breeders were producing horses and bred, to satisfy a need for a general purpose agricultural horse that could be a coach horse or even as a cavalry remount and, more recently for different sporting possibilities in today’s competitive world. Warmbloods vary in conformation depending on their precise ancestry, but breeders have long aimed to combine the class and athleticism of the Arab and the Thoroughbred and the toughness and dependability of the Draught horse.
Warmbloods range in size from 15hh to 17hh+ with varying conformation depending on the breed of horse.
The temperament of the Warmblood horse is calm, sensible, versatile and intelligent, making it an ideal dressage and show jumping horse.
The versatility of the Warmblood horse is evident in the many differing events they compete in, whether it is dressage where the superb precise movements of different gait for example lateral passes of the dressage horse and collected and extended paces are on display or the athletic ability of the agile show jumper or steeple chases, where a variety of stride is needed.
The size of the skeletal system of the Warmblood is somewhere in between the Hotblood and the Coldblood and comparative to the particular bodyweight of the bred. The heavier built Warmblood, Trakehner, 16hh – 17.2hh has an overall heavier skeletal system than another, Dutch Warmblood, 15.3hh -16.3hh.
The cannon bone is again in the middle range not as thick as the Coldblood horse, but not as fine as the Hotblood horse. (This is my assumption as I was unable to find specific information through research)
The muscular make up of the Warmblood horse has evolved between breeds and again varies, depending on the discipline chosen. A Dutch Warmblood show jumper would have well developed Fast twitch muscles to enable it to have sudden bursts of speed needed for quick muscular effort for jumping, where as a Gelderlander carriage horse used in driving competitions would have well developed slow twitch muscles for endurance purposes.
The conformation varies within the Warmblood breed, but usually exhibits strongly muscled, broad quarters and well developed loins with well formed strong hocks for propulsion when jumping. The shoulders are powerful but not sufficiently sloped for great galloping ability. The head is sometimes described as plain. The Warmblood was developed for athletic and different sporting possibilities e.g. dressage, show jumping, eventing and cross country.
Some Warmblood horses are Swedish Warmblood, Selle Français, Hanoverian, Holstein, Trakehner, Oldenburg, Gelderlander and Camargue.
The Hotblood horse is an ancient very pure-bred dating back to the point of domestication, about 6000 years ago. The evolution of the Hotblood horse was from the deserts of Middle East where poor food and harsh, hot and arid climate prevailed, producing a small, fast horse that is both strong and tough. Needing to lose body heat easily, they have fine coats and thin skin with blood vessels near the surface to allow heat to radiate out through the skin. The fine coat and mane and tail assist this. The head of the Hotblood type is short and relatively narrow with large nostrils, allowing hot air to be rapidly breathed out. The ears which hold plenty of blood, are large to dissipate heat, their necks and bodies are often long and oval-shaped, again to facilitate heat loss as compared to the rounded body, of the Coldblood, for conservation of heat. Long legs and tail held away from the body also assist air circulation and heat loss. Such horses sweat freely as a way of evaporating heat.
The Arab, as one example, has a small physique with a tapering head, concave –dished face with long ears and large dark eyes. It shows great presence with its high head and tail carriage, with an almost floating action. It is famous for its stamina.
The Hotblood varies in size between 14.2hh and 16hh + and depending on the breed display differing conformation traits.
The Hotblood horses have an alert temperament which makes them more active than the Coldblood and therefore expend more energy. They are also excitable, and can have a highly strung nature but they also exhibit courage and gentleness, are intelligent and kind.
Most Hotblood horses are industry orientated, such as Endurance riding or Thoroughbred racing etc. and as such are bred to cover as much ground as possible .The gait of the thoroughbred horse has a natural extended action with a smooth trot and an impressive gallop and excellent jumping ability.
Hotblood horses are finer boned and lighter bodyweight than the other two groups, with a greater angle of skeletal pivot points, for quick escape from predatory animals. For example the location of the rotation point on the scapula decides the characteristic action of the forelimb, when rotation occurs near the wither, the foot swings in a longer arch to cover more ground.
The size of the cannon bone of the Hotblood horse is the finest of the three types, the diameter is the smallest in relation to Coldblood and Warmblood.(This is my assumption as I was unable to find specific information through research)
Developed muscles of the rump and shoulder, set on a long body using frequent large strides efficiently converts fast twitch muscles into powerful fast strides. The more, fast twitch fibers a horse has, the more rapid his movement will be and a faster tempo can confirm agility.
The Hotblood was further developed within the “racing” industries e.g. steeple chasing, races and endurance rides .It has enormous strength and endurance qualities, the Thoroughbred the fastest in the world, assisted by conformational points such as lightly built frame, powerful hind quarters and shoulders and long legs giving extra propulsion and a long neck to assist with balance and stride all cover more ground. The Hotblood displays quality.
Some Hotblood Horses; Arab, Thoroughbred, Barb, Akhal-Teke, Anglo Arab.
As discussed previously the three key groups, Warmblood, Coldblood and Hotblood horses were developed through different evolutionary paths, because of geographical restraints. A need for mankind’s use of horses by breeding and cross breeding between the three groups to fulfill a specific need or purpose within the horse world; be it work, play or sports. One type and breed of horse would be more suited to specific roles than others because of conformational characteristics of that breed for .e.g. a heavy Draught horse would be consistently last place at the races, or a light agile Arab would be of no use in a harness ploughing a field. “Horses for courses”
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