Equine: Nervous System

Question 1

What is equine viral encephalitis?

Answer 1

“sleeping sickness”
EEE, WEE, WNV (core vx)
Viruses spread by mosquitos, profound depression/lethargy secondary to brain inflam
rare bc of vx, poor prognosis to graveWh

Question 2

What is equine herpes virus-1

Answer 2

Mild respiratory, abortion storms, severe neurological signs such as lethargy, marked fever, dec anal and tail bone, urine dribbling, ataxia, dog-sitting, recumbency

Question 3

What do you do with EHV-1? Treatment?

Answer 3

QUARANTINE!
tx by general nursing care, sling, anti-inflam and corticosteroids

Question 4

How can you tell the difference btw EHV1 and equine viral encephalitis

Answer 4

EHV1 affects back end more, lots of anal and tail bone loss

Question 5

How does rabies affect horses?

Answer 5

transmission thu saliva of infected animals (ex. foxes, skunks, bats)
bites on muzzle or distal limb
would present with vague neurological symptoms such as generally bizarre behave, aggression, altered vocalization, hypersalivation
ANY HORSE W/ HYPERSALIVATION HAS RABIES - unless proven otherwise
always fatal

Question 6

What is tetanus? What is the other name for it?

Answer 6

‘Lockjaw”
caused by clostridium tetani infection, it is endemic in soil, horses are particularly vulnerable
infection occurs when there is a break in the skin (wounds, surgery)

Question 7

What are the signs of tetanus?

Answer 7

Agitation, stiff “saw-horse” stand, “pump handle” tail, prolapses third eyelid, spasms when sartled, stiff muscles
HYPERSALIVATION - DDx rabies!!

Question 8

How do you treat lockjaw?

Answer 8

with supportive nursing care, high doses penicillin, high doses tetanus anti-toxin, muscle relaxant

prevent with core vx

Question 9

What is cervical vertebral malformation? What is the lay term?

Answer 9

“wobblers”
malformation of the cervical vertebrae by compression of spinal cord or primary/secondary to arthritis
in yg and rapidly growing horses
also middle - geriatric horses
usually present for a non-specific lameness - stepping on own feet, stumbling/falling, progressive ataxia

Question 10

How can you diagnose wobblers, is it progressive?

Answer 10

radiographs, myelogram - areas of spinal cord compression
stabilization surgery

usually progressive - severely affected horses cannot be ridden

Question 11

How does trauma affect neurosensory?

Answer 11

Facial paralysis - muzzle pulled to opposite side of injury, secondary to injury ex post-sx if halter left on
Suprascapular nerve at point of shoulder - “sweeny” - atrophy of infra and suprascapular nerves, unstable shoulder when walking, seen in harness horses with poor fitting collar, horse hits shoulder against fence post/tree

Question 12

How is the neurologic exam performed? What should you keep in mind safely wise

Answer 12

ALWAYS PAY CLOSE ATTENTION! Very ataxic horses can easily fall over and hurt you
1. cranial nerves
2. walk on the straight
3. walk in tight circles
4. tail pull
5. walk over poles/curb
6. straight line w/ head elevated
7. backing up
8. blind folded

Question 13

What dz are vx’s available for

Question 14

What are common symptoms of horses infected with the neurologic form of EHV-1? Why should these horses be placed in quarantine

Answer 14

lethargy, marked fever, dec anal and tail tone, urine dribbling, ataxia, dog-sitting, recumbency. Quarantine bc HIGHLY TRANSMISSIBLE

Question 15

What are two major differentials of a horse presenting with hypersalivation

Question 16

Why should a horse with wobbler syndrome not be ridden?

Answer 16

Because of ataxia, usually progressive