Nervous

Question 1

Describe some abnormal symptoms that may be observed in the head

Answer 1

-Depression, aggression, circling, head pressing
-Blindness
-Nystagmus
-Drooping muzzle, ears, eyes
-Difficulty eating/swallowing, noisy breathing
-Protruding tongue

Question 2

How is a horse determined to be blind?

Answer 2

-no menace reflex (the horse will not flinch when a hand is quickly brought towards its face)
-no pupillary light reflex (a horse’s pupil will not contract when a bright light is shined on it)

Question 3

What is nystagmus?

Answer 3

Abnormal movement of the eye, characterized by rapid, repetitive, involuntary up and down, side to side, or circular movement.

Question 4

What are some abnormal symptoms that may be observed caudal to the head?

Answer 4

-Ataxia (lack of coordination)
-Weakness in the limbs
-Lack of proprioception (awareness of the position and movement of the limbs in space)
-No cutaneous trunci reflex (horse’s skin does not twitch when pinched between the thoracic and lumbar vertebrae
-Single limb abnormalities

Question 5

What sorts of diagnostic tools may be utilized when determining the cause or pathology of neurological disease?

Answer 5

-Radiographs with a myelogram
-MRI (magnetic resonance imaging)
-CT (computed tomography) scans
-Nuclear scintigraphy
-CSF tap
-Electromyography

Question 6

What is Cervical Vertebral Malformation (CVM or Wobblers)? How might it occur?

Answer 6

-A malformation of the cervical vertebrae puts pressure on the spinal cord causing neurological abnormalities.
-Usually identified between six months and three years of age
-Linked to orthopedic disease, may have nutritional and hereditary components
-Occurs comorbidly with arthritis in older horses

Question 7

How is Wobblers diagnosed?

Answer 7

Clinical signs
-Ataxia
-Weakness
-Radiographs with or without a myelogram

Question 8

How is wobblers treated?

Answer 8

-Dietary changes
-NSAIDs
-Surgery

Question 9

How serious is wobblers? What complications may occur?

Answer 9

-Performance-limiting. ~70% of horses operated on will improve, but only around half will be able to perform as athletes

-Trauma arising from a fall or other accident due to ataxia

Question 10

What is EHV-1 (Equine Herpes Virus or Rhinopneumonitis)?

Answer 10

A serotype of EHV that attacks the nervous system, is transmitted through saliva, respiratory secretions and feces.

Question 11

How is EHV-1 diagnosed?

Answer 11

Clinical signs:
-Ataxia (lack of coordination) or recumbency (lying down and unable to rise) ~6-12 days after exposure
-Loss of bladder function

-Presence of an outbreak
-Antibody titres
-Detection of virus in respiratory secretions

Question 12

How is EHV-1 treated?

Answer 12

Supportive care:
-NSAIDs
-Fluids
-Prevention of decubital ulcers
-Bladder catheterization

Question 13

Can the EHV-4 vaccine prevent EHV-1?

Answer 13

There is no vaccine labelled for the prevention of EHV-1, but they may offer SOME protection

Question 14

How serious is EHV-1? What complications may occur?

Answer 14

-Outbreaks are very likely as ~90% of exposed horses will become ill
-Mildly affected horses can recover without complications, but mortality can be as high as ~40%

-Permanent gait alterations
-Permanent loss of bladder function

Question 15

What is West Nile Virus? How is it transmitted? What kind of vector are humans and horses considered to be?

Answer 15

-A viral disease, first introduced to the eastern United States in 1999 before rapidly spreading westwards.
-Birds and mosquitos
-Dead-end hosts, meaning the virus does not accumulate in high levels, so cannot be passed on to other birds and mosquitos

Question 16

How is West Nile Virus diagnosed?

Answer 16

Clinical signs:
-Ataxia (lack of coordination)
-Hindlimb paralysis
-Seizures (uncommon)
-Coma
-Tremors around nose and lips

-Antibody levels (high levels could be due to recent vaccination)
-Virus isolation from blood or CSF

Question 17

How is West Nile Virus treated?

Answer 17

-Supportive care
-NSAIDs

Question 18

How serious is West Nile Virus?

Answer 18

-Mortality rates were once ~35%
-Vaccination has drastically decreased mortality

Question 19

What similarities are there between West Nile Virus and Eastern Equine Encephalopathy(EEE)/Western Equine Encephalopathy(WEE)?

Answer 19

-Both viruses cycle through birds and mosquitos
- EEE and WEE are rarely seen due to extensive vaccination efforts
-Most tetanus vaccines include EEE/WEE (“I need to vaccinate my dear horsey for tetanus, eastern, and western”)

Question 20

What is tetanus? What organism causes it? What organisms are the most susceptible?

Answer 20

-A fatal disease caused by a toxin released from bacteria that live in soil and enter the body through a wound (especially a deep puncture wound by a filthy object, eg. a rusty nail)
-Clostridium tetani
-Horses and humans

Question 21

How is Tetanus diagnosed?

Answer 21

Clinical Signs:
•Stiff, progresses to full body rigidity
•Lips pulled back
•Nostrils flared
•Lockjaw

•History of a wound (especially punctures)
•Horse is not vaccinated

Question 22

How is Tetanus treated?

Answer 22

•Antitoxins
•Antibiotics
•Sedation and anti-convulsants
•Intensive nursing
•Quiet environment

Question 23

How serious is Tetanus? What complications may occur?

Answer 23

•Survival is possible but it can be fater in as little as 5-10 days
•Euthanasia recommended for severe cases

•Further injury can occur due to the horse being unable to stand or function normally