Horses Flashcards
The ability to extend the hock while flexing the stifle is characteristic diagnostic feature of what condition?
Peroneus tertius rupture disrupts the stay apparatus- when intact, this muscle prevents this motion,. Also mentioned: jerking movement as leg moved forward
Horse % dry matter protein
12% (1.3 g/kg, 40g/1000kcal)
Most common cause of maxillary sinusitis
Tooth root abscess (first molars)
Strangulating lipoma signalment
15-20, gelding, obese
Enterolith formation food, type of lith
Alfalfa hay in California; mg ammonium phosphate
Findings: fiddleneck consumption
megalocytosis, bridging portal fibrosis, biliary hyperplasia of liver. (pyrrolizidine alkaloid)
Findings: yellow star thistle
nigropalladial enecephalomalacia- loss of upper motor gnglia leading to loss of inhibition and dystonia (impossible to eat)
Shaker foal syndrome- infectious agent
Clostridium bolulinum pre-formed toxin ingestion only
Shake foal syndrome pathophys
spore toxin blocks acetylcholine at NMJ+ flaccid paresis/paralysis
Shaker foal syndrome CS
weak tongue, weakness, flaccid paralysis, resp depression that cna lead to death
Cerebellum- responsible for
coordination (range, rate, strength of movement), balance, posture
CP deficits are on the ____ side of a brain lesion
Same
Brain region w/ CS: intention tremor, hypermetria, hypometria, ataxia; normal mentation
Cerebellum
What side is the lesion on compared to fast-phase of nystagmus
Fast phase away from lesion
Lesion/head tilt association
Same side
Name two ddx for symmetric ataxia, weakness, limb spasicity, toe dragging
EDM or CVM (wobblers)
Dx EDM
no definitive test, low Vit E suggestive
Club foot pathophys
(flexural deformity of DIPj) - d/t DDF tendon contracture
Most common cuase of bacterial keratitis in horse
Psuedomonas- gram negative (less: e. coli, staph- gram +)
Cantharadin tox- effect
Endotoxic shock and renal failure (blister beetle toxicity)
Agent in Tyzzers Dz
Clostridium piliforme (aka bacillus piliformis)- (the only gram - clostridium!)
Cause of Theiler’s Dz
4-10 weeks post Tetanus antitoxin most commonly (plasma blood)
What is bog spavin
Chronic synovitiswith bilateral effusion of tibio-tarsal joints
What is bone spavin
osteoarthritis of the hock
What important structures are in the guttural pouch
Internal and external carotids, cranial sympathetic trunk, CN 9, CN 7
Blocked by palmar digital
50-70% of the palmar surface of the foot including most of DIPj (except proximodorsal)
Blocked by abaxial sesamoid
Foot and PIPj, skin over palmar pastern and distal dorsal pastern
Blocked by low four point
entire MCPj (fetlock) and distal
Blocked by high four point
metacarpal region, entiere MCPj and digit structures
Tx keratitis with typical agent
Tx with aminoglycoside like tobramycin (Gram neg- Pseudomonas)
What agent/disease is most likely to cause pulmonary abscess, what age is this common
Rhodococcus Equi pneumonia- foals 2-6 months
Dx: Increasing forelimb lameness and short, choppy gait, swelling over fetlock, pain on flexion
Osselets
What are osselets, cause
Inflammation of the periosteum on dostal distal epiphyseal surface of MC3 and fetlock (usually bilateral), chronic stress injury from running
CS, pathophys purpura hemorrhagica
Type III (Ag-Ab complex) usually from strep equi equi, S. e. e. vax or resp pathogens; aseptic necrotizing vasculitis –> hemorrhage, edema, sloughing
Breed predilection- equine night blindness and recurrent uveitis
Apaloosa
Fescue toxicity
prolactin suppresion, thickened placenta, dystocia, agalactica
Red maple tox
heinz body anemia
St John’s Wort tox
Photosensitization, hepatotoxicity
CS EHV-3
papules, pustules, ulcers to external genitalia (including balanoposthitis- prepuce)
Pathophys of all EE’s
mosquito –> lymph spread–> 5d
How can you artificially start breeding season
16 hours of light, 60 days before breeding
What causes sheared heels, tx
heel asymmetry from foot/gait imbalance; corrective shoeing and supportive bar shoes
Ataxic/hypermetric 5-10 d post turnout: MOA, Px
GABA receptor de-inhibition - resolve within days of removing from rye/bermuda grass
Stringhalt agent
sweet pea, dandelion- when both hind affected (trauma cause of unilateral)
Cauda equina syndrome- MOA
Autoimmune
Breed: OA malformation
Arabians
Breed: cerebellar abitrophy
Arabians
Meningitis- age, agent
neonates, secondary to bacteremia
Most common CNS tumor
Lymphoma
Most common tumor in greys
Melanoma
Transmission, breed, signalment of Recurrent Exertional Rhabdomyolysis (RER)
Autosomal dominant with variable expression in nervous 2-3y TB- a degenerative change in myofibers
Tx Recurrent Exertional Rhabdomyolysis
Low carb, high fat - NO high grain- predisposes; less stress
HYPP (hyperkalemic periodic paralysis) breed, transmission, MOA
Fancy QH (paint/appaloosa)autosomal dominant, muscle membrane sodium channels–> weakness, collapse, fascic THIRD EYELID
Chronic mgmt of HYPP
Acetazolamide K-wasting diuretic; genetic test!
Ddx RER; dx, tx
Polysaccharide Storage Myopathy (PSSM)- mm. biopsy- necrosis/atrophy, increased glycogen; reduce stall rest, train gradually, increase fat/decrease soluble carbs