Equine Behavioral Disorders + Botulism

Question 1

What is the most common source of botulism toxin in horse feed?

Answer 1

Round-bale hay (anaerobic fermentation) > square-bale hay

Question 2

What type of botulism is most common in wound and toxicoinfectious botulism?

Answer 2

B (soil, east coast)

Question 3

What type of botulism is most common in forage poisoning botulism?

Answer 3

B (soil, east coast) and C (caracasses in feed)

Question 4

ABX choice for wound or toxicoinfectious botulism

Answer 4

Potassium penicillin

Question 5

Why should you never administer Procaine Penicillin-G for botulism?

Answer 5

Procaine / aminoglycosides potentiate NMJ blockade! -> worsens clinical signs

Question 6

Cerebrum signs vs brainstem signs?

Answer 6

Cerebrum: dullness, BLINDNESS, SEIZURE

Brainstem: dullness, ATAXIA, CRANIAL NERVE dysfunction

not mutually exclusive!

Question 7

What is the reservoir host of equine viral encephalomyelitis? The vector?

Answer 7

birds = reservoir host,
mosquitoes = vector

Question 8

Hallmark sign of viral cause (e.g., EVE)?

Answer 8

Fever

Question 9

When should you vaccinate for EVE?

Answer 9

vector season dictates –> SPRING

Question 10

Three forms of rabies? What form does aggression form?

Answer 10

1.Dumb
2. Furious - aggression, seizures, tremors
3. Paralytic

Question 11

Process for submitting brain to rabies lab?

Answer 11

Remove brain from skull -> sagittal incision -> half chilled to state lab, other half in formalin -> state lab runs fluorescent antibody test

Question 12

Pathogenesis of WNV? Main clinical signs?

Answer 12

virus resides in wild birds -> transmitted to equine (incidental host) and human hosts via mosquitoes

Sudden onset of dullness and inappetence, pyrexic, MUSCLE FASCICULATIONS

Question 13

Neuro signs of WNV?

Answer 13

muscle fasciculations, weakness, ataxia, hyperesthesia, blindness; may progress to recumbency

Question 14

Antemortem vs postmortem dx of WNV?

Answer 14

ante: serum antibodies via IgM-capture ELISA

post: definitive! RT-PCR and/or CSF

Question 15

How is WNV prevented?

Answer 15

VACCINE (annual in temperate climate semi-annual in subtropical climate)

Question 16

Definitive dx for bacterial meningitis in foals?

Answer 16

CSF analysis via spinal tap

Question 17

Neonatal encephalopathy (NE) categories 1 vs 2?

Answer 17

1: uncomplicated foal delivery, sudden onset of neuro signs within first 36 hours

2.: abnormal foal delivery

Question 18

Foal with NE usually has signs of brain dysfunction, including (4):

Answer 18

Question 19

How is NE diagnosed?

Answer 19

presumptive (young, sudden onset of signs); favorable response to tx

Question 20

What makes prognosis for foal with NE poor (3)?

Answer 20

Foal born with dystocia, failure of IgG, fails to respond to tx