Nervous Flashcards
Describe some abnormal symptoms that may be observed in the head
-Depression, aggression, circling, head pressing
-Blindness
-Nystagmus
-Drooping muzzle, ears, eyes
-Difficulty eating/swallowing, noisy breathing
-Protruding tongue
How is a horse determined to be blind?
-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)
What is nystagmus?
Abnormal movement of the eye, characterized by rapid, repetitive, involuntary up and down, side to side, or circular movement.
What are some abnormal symptoms that may be observed caudal to the head?
-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
What sorts of diagnostic tools may be utilized when determining the cause or pathology of neurological disease?
-Radiographs with a myelogram
-MRI (magnetic resonance imaging)
-CT (computed tomography) scans
-Nuclear scintigraphy
-CSF tap
-Electromyography
What is Cervical Vertebral Malformation (CVM or Wobblers)? How might it occur?
-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
How is Wobblers diagnosed?
Clinical signs
-Ataxia
-Weakness
-Radiographs with or without a myelogram
How is wobblers treated?
-Dietary changes
-NSAIDs
-Surgery
How serious is wobblers? What complications may occur?
-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
What is EHV-1 (Equine Herpes Virus or Rhinopneumonitis)?
A serotype of EHV that attacks the nervous system, is transmitted through saliva, respiratory secretions and feces.
How is EHV-1 diagnosed?
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
How is EHV-1 treated?
Supportive care:
-NSAIDs
-Fluids
-Prevention of decubital ulcers
-Bladder catheterization
Can the EHV-4 vaccine prevent EHV-1?
There is no vaccine labelled for the prevention of EHV-1, but they may offer SOME protection
How serious is EHV-1? What complications may occur?
-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
What is West Nile Virus? How is it transmitted? What kind of vector are humans and horses considered to be?
-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
