- The disease caused by WNV produces polioencephamyelitis with lesions in the mid brain, progressing to the hindbrain and distally through the spinal cord. [10]
- The only non neurological sign is fever. [7]
Clinical
signs of 28 horses diagnosed withWNV
at the Ontario Veterinary
College. Based on a table from [5]
| Clinical
Findings |
# of
Horses |
| Ataxia |
28
(100%) |
| Weakness |
23 (82%) |
| Muscle
Fasciculations |
14 (50%) |
| Fever |
13 (46%) |
| Hypersthesia |
11 (39%) |
| Depression |
10 (36%) |
| Recumbent |
10 (36%) |
| Cranial Nerve
Deficits |
3 (11%) |
| Urinary
Dysfunction |
2 (7%) |
| Survived |
16 (57%) |
Common Clinical
signs:
- Sudden or progressive ataxia
- Listlessness
- Hyperexcitability
- Depression
- Apprehension
- Muscle Fasciculations
- Paresis/Paralysis (most commonly of the hind limbs but may affect all four)
- Circling
- Head pressing
- Blindness
- Paresis progressing to a non ambulatory state and coma
- Facial nerve paralysis resulting in and inablilty to eat, a result of damage to Cranial nerves VII, IX and XII