VTS257: Lg Animal Diseases & Nursing

1. Horses
Equine
Mule
- hybrid, cross between horse and
donkey
- Infertile

2. Horse terminology
• Horse- generic term for any equine, intact
male 5 yrs of age or older
• Colt- intact male 4 yrs old or less
• Gelding- castrated male at any age
• Rig/ridgling- male with one or both testicles
absent from scrotum
• Mare- female 5 yrs of age or older
• Filly- female 4 yrs of age or younger

3. • Foal- either sex from birth to weaning ( 4-6
mo)
• Weanling- either sex from weaning to 12
months of age
• Yearling- either sex 12-23 mo
• Maiden- a horse of either sex that has not
won a competition, female that has not had a
foal

4. • Hand- horses height is measured in hands at
the highest fixed point, the withers, one hand
is 4 inches
• Near side- left side of horse
• Far/off side- horses right side
• Cold blooded/hot blooded- refers to
temperament of the horse
• Stallion- intact male

5. Colors of Horses
• Bay
- Brown haircoat
- Black mane and tail
- Black points, muzzle, distal limbs
- +/- dorsal stripe

6. • Chestnut/sorrel
- red, copper colored coat
- Same colored mane, tail or flax colored mane
and tail
• Grey
- dapple, flea bitten
- All grey horses are born dark, black, lighten
with age

7. • Black
- Very rare color, no brown hair on muzzle,
flanks, medial limbs
• Dun, buckskin
- Tan to honey color, black mane and tail
- Black points, dorsal stripe
- +/- horizontal stripes on limbs

8. • Palomino
- Cream to dark honey colored haircoat
- White mane and tail
- No black markings
• Roan
- White hairs interspersed in coat, color does not
change significantly with age
- Red roan- chestnut base coat
- Blue roan- black or grey base coat

9. Head Markings
• Star
• Strip
• Snip
• Blaze
• Bald face

10. Leg markings
• Coronet
• Half pastern
• Pastern
• Sock
• stocking

11. Identification
• Tatoo
• Freeze brand- applied with liquid nitrogen,
hair grows in white
• Heat brand- heated iron, hair does not grow
back
• Microchip- in middle 1/3 of neck in nuchal
ligament
• Foal certificates- detailed physical description

12. Common Breeds
• Quarter horse
• Paint horse
• Arabian
• Thoroughbred
• Appaloosa
• Morgan
• Tennessee walker
• Standardbred
• Draft horse

13. Draft horse breeds
• Clydesdale
- feathers, blaze, mostly bay, Budweiser horses
• Belgian
- Chestnut to palomino, blaze
• Percheron
- black, dappled
Ponies
Shetland, Hackney

14. Psychology of prey animals
• Safety
- If a horse does not feel safe, its handler is not
safe
- Training, interaction with a horse cannot
progress if horse feels unsafe, if frightened
- Physical punishment, installation of fear is not
an appropriate training technique

15. • Food:
- Bribing a horse with food is no more effective
than buying a misbehaving child food to get
him to settle down
- Food may be used as a reward for correct
behavior but care must be taken

16. • Comfort:
- Training zone
- Given a choice, horse will choose comfort
- Horses do not seek approval the way dogs do,
if they do something right its because they see
a benefit for themselves in the behavior

17. • Defenses:
- flight, evasion
- Biting
- Kicking
- striking

18. Physiology of Prey animals
• Gastrointestinal- continuous gastric acid
secretion, permits constant, continuous
ingestion of small amounts of feed, grazing
• Musculoskeletal
- Stay apparatus- permits horse to sleep
standing up, horse appears larger to predators
and its ability to flee is enhanced
- Nuchal ligament- allows horse to hold head up
without muscular effort, energy

19. • Reproductive
- Stage II labor is less than one hour
- Foaling occurs 12-3 am
- Foal is ambulatory, able to keep up with herd
within 6 hours of birth

20. Sensory Capabilities of the horse
• Vision
1. monocular, single eye field of vision
- Depth perception is based on memory
- Unable to triangulate to identify size or
distance of unfamiliar items
2. binocular, two eye field of vision
- ears, eyes rotate forward
- 65 degrees

21. 3. Color perception
- Dichromatic
- Red, blue and gray
4. Night vision
- Rods predominate in retina
- Acute, better than humans and most
predators night vision

22. 5. Hearing
- Ears swivel independently
- Can precisely locate origin of sound,
triangulation
- Can listen in several directions at once
- Ear position indicates what horse is listening
to

23. 6. Olfactory
- Recognition of other herd members, humans
- Recognition of reproductive status of horses in
the herd
7. Tactile
- Grooming behavior establishes social bonds
and hierarchy within the herd

24. Interaction with the horse
1. Equine body language
a. Warning signals/threatening behavior
- Pinning ears, baring teeth
- Turning hindquarters toward intruder, lifting
hind leg
b. compliant/non threatening behavior
- Ears forward, head in neutral position, chewing

25. • Human body language
- Eye contact with the horse acknowledges horses
presence
- Maintaining eye contact is a sign of dominance,
be careful who you challenge
- Physical approach, approach diagonally, to the
shoulder, least threatening,
- Physical contact, contact trunk before limbs
- Let hand tell horse where you are going
- Push, don’t pull

26. General Terms
• Tack- equipment
• Cinch girth- holds saddle on, some horses able
to puff chest out so girth can get loose
• Bit- part in mouth
• Shod- put shoes on, having shoes on
• Sulky- special racing cart
• Hunter- jumps fences
• Float- filing teeth

27. • Cribbing and windsucking- take top teeth and
put them on a hard surface, uses neck muscles
just right to suck in air.
• Weaving- going back and forth in place
• Furlong- distance measured on a racetrack
• Cover- stallion breeds the mare
• Whirl- cowlick on head

28. Restraint Basics
• Safety- the individual restraining the horse is
responsible for the safety of all persons
present
• Halter- allows you to control the horses head,
if you can control the head, you can control
the horse

29. Lead Shank
• Never tie yourself to a horse
• Never leave a lead shank on the ground
• Applications
a. Chain over nose
b. Chain over gums, not appropriate for leading
a horse

30. Tying
• Always use a quick release knot
• Always tie at or above head level
• Use tie length that will not permit horse to get
a leg over slack and get entangled

31. Twitch
• Induces release of endorphins, duration of effect 15
minutes
• Not appropriate for procedures of longer duration
• Long handled twitch
Skin Twitch
• Grabbing hold of skin over shoulder, diverts horses
attention
• Redirects horses apprehension, anticipation, does not
induce endorphins, just distraction
Ear Hold
• Useful for steadying the head

32. • Center of gravity
- Make it physically difficult for horse to kick, rear
or evade
- In order for a horse to rear, he must shift all his
weight onto his hind legs
- Prevent weight, prevent rearing
- Horse at rest carries 60% of his weight on front
legs, increasing speed increases the %
- To keep him from rearing, keep him moving

33. Stocks
• Most commonly used for reproductive
procedures
• Rectal palpation, ultrasound, AI, embryo
transfer
• Still requires a handle at the head
• Always be aware of your position with respect
to rigid immoveable structures

34. • Breeding hobbles- prevent mare from kicking
stallion during breeding
• Tail tie- useful in anesthetic recovery and
management of neurologic patients
• Sling- useful in neurologic patients, rescue
situations, management of starvation cases
- Introducing horse to sling must be done
carefully as flight response is very strong

35. Equine Dentistry
• Age determination
- Educated guess regarding age of horse
- Wear patterns affected by diet, behavior,
anatomic abnormalities, trauma
- Teeth do not grow, they continually erupt over
horses lifetime
- Healthy horses die of old age because of tooth
loss, inability to access nutrients
- NOTE: upper molars extend into frontal sinus

36. • Deciduous incisors erupt
I1- 6 days
I2- 6 weeks
I3- 6 months
• Adult incisors erupt at, and wear at
- I1- 2 ½ years 3 years
- I2- 3 ½ years 4 years
- I3 – 4 ½ years 5 years

37. Cups Disappear
• Upper I1 6 years
• Upper I2 7 years
• Upper I3 8 years
• Lower I1 9 years
• Lower I2 10 years
• Lower I3 11 years

38. Occlusal surface of incisors changes
from retangular to triangular as horses
age
• Galvaynes groove (I3)
- Appears 10 years
- Extends ½ down tooth 12 ½ years
- Extends entire tooth 15 years
- ½ way gone 17 ½ years
- Gone 20 years

39. Incisor Angle
• Becomes more acute as a horse ages
• Caps- decidous teeth that remain present on
the erupting surface of adult teeth
• Canine teeth- found almost exclusively in
males
• Wolf teeth- first premolars, normally extracted
when a young horse is trained to accept bridle

40. • Bars- toothless region on mandible between
incisors and molars. The bit sits here. Site
where oral meds are given
• Eruption bumps- rounded boney
enlargements palpated on bottom of lower
jaw when adult molars are erupting. Normal
in 2-4 yr olds. Not painful
• Parrot mouth- overbite, impairs horses ability
to tear off grass or bite pieces of hay.

41. Locomotion/lameness
• Locomotion
- bipedal- 2 legged, center of gravity thrown
forward, limb extended to break the fall
- Quadripedal- 4 legged, wheelbarrow effect (
60%, 40% weight distribution)

42. Gaits
• Walk
- 4 beat gait
- No suspension phase
- LH, LF, RH, RF
• Trot/jog
- symmetrical, 2 beat gait
- 2 legs bearing weight at once
- Suspension phase ( all 4 legs off ground)
- LH/RF RH/RF ( legs on one side move in unison)

43. • Pace ( standardbred only)
- LH/LF RH/RF ( legs on same side move in unison)
• Canter/lope
- Asymmetrical 3 beat gait, 1 foot down, 3 feet
follow
- Lead foreleg, single leg loaded with entire body
weight
- When circling, the horse should be on the inside
lead
- LH- RH LF RF

44. • Tennesse Walkers is a manufactured gait

45. Hoof Care
• No foot, no horse
• 90% of lameness is in the foot
• Hoof management
- sanitation, moisture control
- Hygiene: hoof pick, hoof maintenance,
shoeing, trimming interval
- Footing: weight must be born on hoof walls,
not sole, deep sand can bruise foot

46. Horseshoeing
• Protection
• Traction
• Support
• Therapeutic/orthopedic correction
- Angle
- Toe length
- Increased support
- Weight adjustment

47. Lameness evaluation
• Passive evaluation- pointing a limb, reluctance
to move
• Gait analysis- best performed at a trot,
straight line and circling in both directions
- Head nod: horse alters center of gravity to
decrease weight load on painful leg
- Sound of horses hooves striking hard
pavement at trot may indicate uneven weight
load even without head nod

48. • Palpation: cardinal signs of inflammation
- Rubor- redness
- Dolor- pain
- Tumor-swelling
- Calor- heat
• Diagnostic nerve blocks- gait eval after block
• Radiology- bone evaluation

49. • Ultrasonography- soft tissue evaluation
• Nuclear scan- injection of radioactive material
and detection of distribution in tissues
- Note: feces, urine, bedding radioactive for 24
hours, special disposal license
- Hot imaging: radioactive nucleotide
accumulates in areas of bone remodeling
- Cold imaging- absence of radioactive material,
ex cold spot in lung due to abcess

50. Common Lamenesses
• Buck shins- tearing or damage to soft tissue in
front of cannon bone
• Splints- lateral and medial to cannon bone
- Additional bone growth on splint bone and
soft tissue between splint bone and cannon
bone caused by trauma

51. • Suspensory ligament injury
- Supports fetlock, ( ankle)
- Harder to heal
- Rest is key
• Bowed tendons
- Can happen with overexertion
- Similar to sprained wrist in humans
- Ruptured tendon is very bad
- Cold therapy and supportive wraps, blistered,
fired, laser, ultrasound and magnets

52. • Osselets
- Injuries to front of fetlock joint
- Bulging and round
- Excessive trauma and tearing of soft tissue
• Ringbone
- Boney growth in pastern area in the joints
- Foot swollen around coronary band
- Low ringbone is just below fetlock
- High ringbone sometimes resembles splint

53. • Sidebone
- Involves coffin bone
- Calcifies due to traumatic injury
• Grease heel
- Irritation of skin caused by dirt, wet
environment
- Infection of sebaceous gland

54. • Gravel hoof
- Irritation to sole of hoof on white line
- Irritation or separation causes infection which
comes out at coronary band
• Sole abcess
- Trauma to sole and infection
• Thrush
-bacteria that live in horses hoof, similar to foot rot
- Chlorox and water to clean feet and stalls

55. • White line disease
- Bacteria in white line of horses hoof
- Sloughs hoof wall and shoe
• Navicular disease
- Navicular bone behind coffin in hoof
- Horse acts like he is walking on glass
- Correct diet, correct shoeing

56. • Laminitis
- Founder
- Inflammation of sensitive lamellae of hoof
- Coffin bone rotates downwards
- Mild to extensive
- Shoeing to help correct

57. Treatment terms
• Freeze- liquid nitrogen
• Fire- electrical iron, pin fire to cause irritation
and healing
• Neurectomy- denerving foot to make horse
“sound”, very dangerous
• Corrective shoeing- changing angles of feet
and legs

58. Treatments
• Adequan
- Inhibit lysosomal enzymes
- Reduce synthesis of prostaglandins
- Stimulate production of hyaluronic acid
- Create chondroprotection

59. • Legent ( sodium hyaluronate)
- Increases lubrication
- Decreases prostaglandins
- Stimulates production of hyaluronic acid
- Systemic or in joint

60. • Corticosteroids
- Relief from pain and inflammation
- Stabilizes lysosome membrane
- Decreases vasodilation to decrease edema
and fibrin deposition
- Decreases neutrophils
- Decrease prostaglandins

61. Equine Colic
• A symptom, not a diagnosis
• Abdominal pain
• Causes
- Gastrointestinal
- Uterine contractions, abortion, foaling, uterine
involution post foaling
- Urethral, cystic calculi, peritonitis
- Administration of PGF2alpha
- Referred thoracic pain, myocardial infarction, pleuritis
- Testicular torsion

62. • Clinical signs
- sweating, pawing
- Looking at flanks
- Frequent lying down then getting back up,
sometimes violently
- Rolling, stretching out as if to urinate
- Straining to urinate or defecate

63. GI tract of horse
• Protection
- Physical barrier to keep outside in and inside
out, immune function
• Elimination
- waste, non-digestible materials, bile, bacteria,
parasites, water
• Absorption of nutrients, water
• Secretion of digestive enzymes, water

64. 24 hours maintenance intake
• Horse consumes2-3% of body weight in
roughage ( 20-30 lb/1000lb bw)
• Horse consumes 10-15 gallons of water a day

65. GI diseases that can result in colic
• Inflammation
- Gastric ulceration
a. foals- secondary to stress, concurrent disease
b. Adults- management related
- enteritis: viral
- Potomac horse fever- bacterial
- Typhlitis, inflammation of cecum, parasitic
(tapeworms)

66. • Displacement without displacement ( gas
colic)
- Often weather related
- Decreased barometric pressure> increased gas
volume ( boyle’s law)

67. • Obstruction
- ingesta-impaction-associated with decreased
water intake
- Parasites, ascarids
- Meconium- foals swallow amniotic fluid with
meconium
- Enteroliths in older horses, often form around
a foreign body

68. • Displacement without strangulation
- Pelvic flexure displacement
- Right dorsal displacement
- Left dorsal displacement

69. • Displacement with strangulation
- hernia: umbilical, inguinal, scrotal
- Epiploic foramen entrapment, mesenteric tear
- Strangulation lipomas
- Intussesception- altered segmental peristalsis
often secondary to diarrhea or parasitism
- Volvulus, torsion

70. • Ishemia/ischemic necrosis ( without
displacement) thromboembolic colic
• Rupture
- Gastric perforation due to ulceration or bots
- Intestinal colonic rupture secondary to
ischemia

71. Diagnosis of colic
• Diet
- type, amount, quality of feed, frequency of
feeding
- Change in diet????
• Exercise
- Type
- Frequency, intensity, pattern of exercise
- Changes in exercise

72. • Deworming
- frequency, product used
- Reliability of administration
- Fecal exams to detect small resistant
strongyles

73. • Management
- Housing in groups or individually, competition
for feed can lead to bolting food
- Pasture vs stall
- Sand lot
- Water supply, quality

74. • Reproductive status
• History of previous colic episodes
• Behavioral abnormalities such as cribbing,
eating habits
• Level of management, monitoring

75. Physical exam for colic
• Temperature
- >105 inflammatory disease ex. Enteritis
- 99-100.8 normal, does not rule out serious
disease
- <99 hypovolemic shock, devitalized tissue

76. • Pulse
- <44 normal does not rule out serious disease
- 48-66 pain, +/- cardiovascular compromise
- >60 severe pain, shock, circulatory collapse
• Respiration
- 12-16 normal, does not rule out disease
- >24 pain, increase due to visceral distension with
gas or fluid
- Acid base imbalance due to electrolyte loss
- Hypoxia due to cardiovascular collapse

77. • Mucus membranes
- Color
- Hydration, moist vs tacky
- Capillary refill time
a. <2 sec normal
b. >2 sec, delayed, >4 severe cardiovascular
collapse

78. • Abdominal auscultation- presence or absence
of gut sounds
• Pain assessment/characterization
- Intermittent vs constant
- Severity
- Response to analgesics

79. • Rectal exam by vet
• Nasogastric reflux- quantity, color/odor, ph
• Abdominocentesis- belly tap
- Total protein
- Cellularity
- Bacteria
• PCV or hemocrit

80. Treatment for colic
• Surgical treatment of a medical case is highly
counterproductive
• Medical treatment of a surgical case of colic is
fatal

81. Medical treatment
• Fluid management- gallons IV, fluid of body
trapped in intestines due to no reabsorption,
monitor PCV for overhydration
• Pain management
a. Banamine
- NSAID
- Potent analgesic, can mask surgical colic,
- Binds endotoxins,
- PO, IV, IM

82. b. Phenylbutazone
- NSAID
- Contraindicated in GI disorders
- Associated with ulceration of GI tract
- PO, IV, never IM or SQ

83. c. Xylazine ( rompun)
- Potent sedative and analgesic
- IV or IM
d. Butorphanol ( torbugesic)
- Potent analgesic, some degree of sedation
- IV
- Controlled substance

84. e. Detomidine ( dormesedan)
- Potent sedative and analgesic
- IV

85. Return of GI function
• Lubricants, surfactants, cathartics
- Mineral oil, lubricants
- DSS dioctyl sodium succinate, surfactant
- Magnesium sulfate ( epsom salt) cathartic
• Intestinal protectants
- Kaolin pectin
- Pepto bismol useful in diarrhea, 1ml/lb every
4-6 hours

86. • Antibiotics?
- Judicious selection due to gut permeability
and altered flora
- Don’t use oral with compromised gut function

87. Surgical correction
• Correct displacement
• Decompression
• Enterotomy
• Resection and anastomosis
Post surgical complications
- Abdominal wall herniation
- Peritonitis
- Adhesions, stenosis
- Chronic malabsorptive disorder
- Chronic diarrhea, soft feces
- Founder ,laminitis
- Chronic recurrent colic

88. Equine Diseases
• Rabies
- virus, infects CNS
- Transmitted when bitten by infected animal
- Signs: inability to swallow, colic, abnormal
behavior, “just not right”
- Prev: vaccination
- TX: none
NOTE: assume rabies first

89. • Equine Viral Rhinopneumonitis
- Signs- may abort, mild upper respiratory
disease, watery discharge
- prev: vaccination, must be repeated because
the vaccine has a short duration, during
pregnancy vaccinate at 5, 7, 9 month
- TX: supportive

90. • Equine influenza
- Viral disease
- Trans: inhale infective material in droplets
- Signs: sudden fever, weak, cough with watery
discharge from nose

91. • Tetanus
- Cl. Tetani invades an open wound
- Signs: muscle spasms, sawhorse, 3rd eyelid
protrudes, nervous
- Tx: none
- Prev: vaccination

92. • Lyme disease
- Borrelia burgodorferi
- Signs: fever, lameness, swollen joints,
- Dx: signs, blood tests, history of ticks
- Tx: antibiotics and antiinflammatory
- Prev: tick control

93. • Equine Infectious anemia ( swamp fever)
- Viral disease of horses
- Signs: anemia, fever, weakness, eventual
weight loss, legs swell, lower abdomen swell
- DX: Coggins test ( necessary for sale,
movement of horses) REPORTABLE
- Trans: horse flies, mosquitos, lice
- TX: none, euth, isolation

94. • Strangles
- Streptococcus equi
- Signs: throat swelling, infection, fever, abscess
in mandibular lymph nodes
- Trans: secretions from abscess
- Tx: penicillin until abscesses dry up

95. • Equine protozoal myeloencephalitis
- Sarcocystis neurona
- Signs: ataxia
- Trans: ingest parasite in feed
- Tx: NSAIDS, DMSO
- DX: western blot test

96. • Eastern Equine Encephalitis
- Viral
- Trans: mosquitoes
- Signs: behavior change, unsteady, seizures and
death
- Tx: none
- Venezuelan and Western EE as well

97. • Vesicular Stomatitis
- viral, resembles foot and mouth
- Trans: ?
- Signs: ulcers, blisters in mouth
- TX: supportive
- DX: isolate virus from lesion
- REPORTABLE

98. • Navicular disease
- Ulcer on navicular bone in foot,
- Caused by surface, shoeing problems,
heritable
- Signs: won’t put weight on heel, toe walker
- Tx: shoes and soft ground

99. • Potomac horse fever
- Bacterial Ehrlichia risticii
- Trans: arthropods
- Signs: slight fever, anorexia progresses to high
fever, projectile watery diarrhea for 10 days
- DX: antibody test
- Prev: vaccination

100. • Equine viral arteritis
- Viral
- Signs: swelling of lower legs, abdomen,
sheath, mm of eyes, nasal discharge, fever
- Prev: vaccination

101. • West Nile Virus
- Viral
- Signs: ataxia of rear legs and eventually go
down
- Trans: mosquitoes
- Prev: vaccination

102. • Chronic obstructive Pulmonary disease COPD
- Reaction to fungal spores on hay or straw
- Signs: roaring, heave line
- TX: steroids, inhalants, injectables

103. • Neurologic Equine Herpes Virus
- Equine herpes virus
- Signs: respiratory illness, fever, nasal
discharge, cough
- 80% of horses over 2 are carriers
- Shed when stresses

104. • Neurologic syndrome of EHV
- weakness, ataxia, hind end paralysis
- Mutation led to neurologic form
- Restrictions placed on horse travel
- 30-50% euthanized
- Shed virus in nasal secretions
- Quarantined farms

105. • EHV vaccination
- Killed vaccine does not prevent neurologic
form
- Modified live vaccine, Rhinoimmune, may
protect from neurologic form
- Rhinoimmune recommended for exposed and
stressed horses, every 90 days with events or
3, 5,7 , 9 mo. of pregnancy

106. • Founder/laminitis
- causes: toxemia, carbohydrates, trauma,
- Signs: lameness
- DX: stance, pulses, hoof testers at toe, rads
- Tx: address cause, shoeing, NSAIDS

107. • Wobbler Syndrome
- Cervical vertebral instability
- Young 4-24 months, rapidly growing
- DX: history, neuro exam, rads, myelography
- TX: stabilize vertebra, euth

108. • Tying up, Rhabdomyolsis, Monday morning
disease
- Cause: high grain diet, over exercise, no cool
down
- Signs: stiff, sore gait, sweating
- Dx: serum CPK, myoglobinuria
- Tx: NSAIDS, rest,

109. • Idiopathic Laryngeal hemiplegia (roaring)
- Paralysis of left side of larynx
- Signs: exercise intolerance, inspiratory noise
- Dx: history, signs, atrophy of laryngeal muscle
- TX: depends on use, surgery

110. • Exercise induced pulmonary hemorrhage
- Rupture of blood vessels in lungs
- Throroughbreds, standardbreds
- cause: trauma, exercise
- Dx: epistasis post exertion
- TX: furosemide, blood pressure meds

111. • Sarcoid
- Neoplasia or viral
- Signs: ulcerated nodular mass on trunk/neck
- Tx: immunotherapy, surgical debridement

112. • Melanoma
- Neoplasia of gray horses
- On perineum, penis, muzzle, periocular
- Dx: presentation
- TX: cryosurgery, cimetidine

113. • Proud Flesh
- Granulation tissue out of control, usually on
lower limbs
- Tx: topical digestive enzymes, trypsin, surgical
excision and skin grafts

114. • Recurrent uveitis, moon blindness, periodic
opthalmia
- Cause unknown or leptospirosis
- Signs: red, painful eye, conjunctivitys, tearing,
blepharospasm, anterior chamber cloudy, +/-
cataract, - corneal stain
- Tx: topical corticosteroids