VETC 101 – Equines
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Equus – Latin name for horse (original Mongolian horse (from Asia) kept in Bronx zoo)
o Equus caballus – the domestic horse
o Equus asinus – donkeys
o All descended from eohippus from 45,000,000 years ago (small horse)
Aging
o Horses are considered to become one year older on January first
o This derives from the racing industry, which divides horses into age groups
Sizing
o Horses are measured (for height) by way of “hands”
o A hand is 4 inches
o Horses are measured from the ground to the withers
o Approximate sizes of groups of breeds:
 Miniature – under 8 hands
 Pony – 10-14 hands
 Light – 14-17 hands
 Draft – 17-19 hands
Taking a part
o Carpus – wrist (Knee)
o Poll
o Withers
o Pastern
o Fetlock
o Stifle (gaskin)
o Hock – tarsis (ankle)
o Croup
Breeds
o American miniature horse – Teeth are “normal” size; thoracic limbs are foreshortened
 Dwarf – out of proportion
o Shetland pony – Wide-set eyes, relatively short limbs
o Thoroughbred – Powerful hindquarters; “high-strung”
o Clydesdale – Long, rounded muzzle, long hair over hooves (feathering)
o Blood characterisitic
 Hot blooded animals (Arabians, thoroughbreds) have a faster metabolism
 Cold blooded animals have slower metabolic rates (draft horses)
 A cross of these is considered a warmblood (Hanoverian)
 Hanoverian – Like a light horse but without the heavier musculature
o Tennessee Walker – special gait characteristic
Babies
o Foal – newborn to January first
o Suckling – still nursing
o Weanling – most foals weaned at 3 – 6 months old
Age-related names
o Colt, filly – a male or female (respectively) up to about 2 years old
o Stallion – intact male at two or three years old
o Gelding – neutered male
o Mare – female at 2 or 3 years old
o Broodmare – pregnant female
o Yearling – one year old
o Aged, or mature – over 4 (larger breeds) or 5 (smaller breeds) years old
Donkey and mule
o Donkey and zebra can mate with domestic horses
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o The cross of a horse and a donkey produces a mule
o Generally, mules are sterile
o Donkey: jack – male and jenny – female
o Mule: mule and hinny
o Equus zebra: Grevy’s (round ears), Burchell’s
The uses of horses
o Competition (show, racing)
o Pleasure (riding, “pasture ornament”)
o Work (particularly draft horses, donkeys)
o Competition
 “Equestrian event” is the general term
 Dressage: formal, looks at obedience and beauty of form
 Hunter/jumper competition: obstacle courses, speed
 Polo
 Rodeo
o Racing
 Turf: on grass (in Great Britain the track is run back-wards)
 Soil: Kentucky Derby, etc.
 The above are done at a gallop; harness racing is done at a trot or other pace
 Dangers of racing
 Dehydration: racing horses can lose two gallons of sweat per hour
 Sweating heavily causes a horse to be lathered
 Hyperthermia – fever
 “Tying up” (“Monday morning disease”) – build up of lactic acid causes them to tense up
o Pleasure
 Types of riding tack: English, Western (with pommel)
 Dressage is usually done with English tack
o Gait
 Walk: four beats, equal time between steps
 Trot: two beats, diagonal legs hit ground simultaneously
 Pace: two beats, legs on same side hit ground together; faster than trot
 Standardbreds have the pace as a “natural” gait
 Gallop: The fastest gait, four beats
 Not symmetric; the first foot that hits the ground is called the lead; horses can have a
left lead or right lead
o Breeding – typically single births, rarely they will have twins
 Horses are seasonally polyestrous; in this country, the mare will be in heat every 21 days in
spring and summer
 Broodmare: pregnant female; said to be in foal
 11 month pregnancy. So foal season is when: early spring
 Waxing: As the colostrum starts to flow, just prior to birth, a wax-like material is noted on the
nipples
 The mare can come back into heat in 7-12 days; the first heat after birth is called “foal heat”
(but generally cannot get pregnant at this time)
 The next heat is 21 days later (usually last a few days)
 Maiden: a mare who has not had a foal yet – Also refers to a horse, male or female, running its
first race (or racing without having won)
 Ruffian – triple crown winner (female) usually males and females do not race together
 “Get”: progeny (foal)
 Stand at stud: provide sperm
 Teaser: the male a broodmare is paraded past to see if she is in heat
 Fertilization: natural cover or AI (artificial insemination). Some breeds are not permitted to use
AI (thoroughbreds)
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Breed registries (“stud books”) allow owners and potential clients to follow the animal’s
progress
Housing
 Pasture, corral (paddock), stall
 Box stall: large enough for horse to turn around and lie down
 Opposite is tie/standing stall
 Riding arena
Feeding a horse
 Monogastric herbivore – 1 stomach, doesn’t eat meat
 Cecal digestion – horses ferment food in cecum, large intestine begins and small intestine ends.
 Fiber, especially cellulose, is supplemented by grains and occasional fruit and vegetables
 And then there’s the water
 A 1000 lb. horse needs 5 to 10 gallons of water a day
 A particular problem occurs in winter, when water troughs may freeze over
Equine dentistry
 Horse’s teeth are hypsodont (grow throughout life)
 Wolf tooth: a small sharp tooth that serves no real purpose, and is usually removed
 Floating teeth: filing off “points”
 Buccal – over growth of tooth near cheek
 Lingual – “ “ near tongue
Restraint
 Approach slowly, usually from the left
 While the horizontal pupil gives a wide range of vision, the fact that the eyes are on opposite
sides of the head means that an approach directly from the front can scare him/her
 A halter is used to catch and hold the horse
 Twitch – Applies enough pressure to release endorphins and relax the animal
Hooves and farriers
 Hooves grow at a regular rate; they need to be “shaped” (filed down) on a consistent basis
 Proper hoof health will extend the life of a horse, and help prevent laminitis
 Laminitis stance – head forward, down, neck extended, stance is wide apart
 Laminitis
 The laminae are the tissues that support the wall of the hoof
 If they become inflamed, or if the blood supply is interrupted, the laminae are damaged
 Associated with lameness and hoof distortion
 Chronic condition is known as “founder”
 Lameness exam
 A good routine part of a physical exam, and the particular area of expertise for equine
practitioners and technicians
 Horseshoes
 Generally only used if the horse will be spending time on a hard surface, or used for
work or racing, or has a specific medical problem
 Shoes can be metal or rubber
 There are corrective shoes for special problems
Preventive care
 Regular physical exams – TPR (temp, pulse, respiration over 1 minute)
 Vaccinations, Hoof care, Dental care
 Parasite control
 Ectoparasites and endoparasites can have a major effect on equine health
 Bots (fly larvae), Strongyles (GI worm)
 Important vaccines: Rabies, Tetanus, Eastern (or Western) encephalomyelitis, and West Nile
disease, Rhinopneumonitis/influenza, Equine viral arteritis (inflammation of arteries)
 EIA – Equine infectious anemia: spread by biting a sick horse (or a carrier), usually involving a
mosquito or biting fly. Not Treatable!
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Test: Coggins test
Required at most horse shows and competitions (including the Olympics)
Treatment is quarantine or euthanasia (a Chinese vaccine is available; it is of
questionable use)
Common horse health issues
 Colic – not a diagnosis, just means abdominal pain
 Can be as simple as gas, as complex as intestinal torsion
 Signs can include rolling on the ground, anorexia, sweating, anxiety
 There may be a nutritional component to colic
 Treatment of colic – fluids
 COPD
 Chronic obstructive pulmonary disease; AKA “heaves”
 Usually from allergies, or viral disease; commonly seen in race horses
 Heave line – on bottom of the belly from breathing.