Neurological Disorders in Adult Cattle Flashcards
Hx taking of neuro in cattle?
Onset/duration.
Individual/outbreak.
Age.
Calving status.
Nutrition/management system.
Access to poisons?
Impact of season?
Distant exam?
Demeanour.
MSK signs - standing/recumbent, ability to walk, gait.
Central deficits.
Clinical exam.
General:
- many neuro conditions also have effects on other organ systems.
- differentials will often include conditions w/ systemic signs.
- may guide tx and px.
TPR, hydration status, rumen function, pyrexia.
Neuro exam.
Cranial nerve deficits.
Revise neuroanatomy - which deficits are seen w/ damage to which nerves.
Can be quick and simple!
What cranial nerve does looking at facial symmetry tell you abut?
Cranial nerve VII - facial nerve.
What signs may tell you about a deficit in nerve XII - hypoglossal, nerve IX - glossopharyngeal, neve VIII - vestibulocochlear.
Head tilt (vestibulocochlear), lingual paralysis (hypoglossal), drooling, inability to swallow (glossopharyngeal).
Testing facial sensation.
Tap or poke face.
Tests the trigeminal nerve.
Menace response.
Tests ability to see and ability to move eyelids.
PLR.
Difficult in FAs as need to get the environment dark enough.
Other eye abnormalities?
Nystagmus or strabismus.
Peripheral nerve assessment.
Sensation.
Motor control.
Other diagnostics in neuro cases?
Haematology - WBCs.
Biochemistry.
Serology.
(CSF analysis).
What aetiology types are seen in cattle neuro cases?
Infectious, traumatic, metabolic, toxic.
- Listeriosis aetiology.
- Listeriosis epidemiology.
- Listeria monocytogenes.
- gram +ve.
- facultative anaerobe. - Sporadic cases or outbreaks.
Listeriosis pathogenesis?
Spoiled feed:
- poorly preserved silage.
- soil content.
Exposure to soil.
Entry via oral mucosa»_space; trigeminal nerve»_space; brain stem»_space; meningoencephalitis.
2 week delay between ingestion and signs.
Also abortion / uveitis.
Listeriosis clinical signs.
Depression.
+/- pyrexia.
Neuro signs dependent on cranial nerves affected by micro-abscesses.
- Trigeminal nerve – weakness in masticatory muscles.
- Facial nerve – drooping ear, eyelid, muzzle (asymmetrical appearance).
- Vestibulocochlear nerve – head tilt, ataxia, circling.
- Glossopharyngeal and vagus
– dysphagia.
- Hypoglossal – protrusion or weakness of the tongue.
+/- weight loss.
+/- dehydration.
Dx of listeriosis?
Clinical signs.
CSF? Proteins and WBCs.
PM for definitive.
Tx of listeriosis.
Nursing care - dehydration / ability to eat.
NSAIDs.
Systemic ABX.
- G +ve.
- Cross BBB.
- high dose penicillin.
Px of listeriosis?
Depends on speed of dx and severity of signs.
May have some permanent neuro deficits.
Note: zoonosis - milk from infected cows should be discarded.
What is BSE?
Bovine Spongiform Encephalopathy.
“Mad Cow Disease”.
Rare but notifiable, so important!
BSE clinical signs?
Vary in severity.
Proportional to degree of stress.
Can have temporary remission.
Behaviour changes:
- Apprehension (86% of cases).
- Change in temperament (78%).
– aggression.
Nervous signs:
- hyperaesthesia (75%).
– kicking at milking.
- compulsive licking.
- nibbling response when scratched
- bruxism.
- ear tremors / twitching.
HL motor deficits.
- ataxia, hypermetria, paresis, knuckling, stumbling, recumbency.
Loss of BC in face of usually normal appetite.
Dx and management of BSE?
Clinical signs.
Exclusion of other DDx (esp. hypomagnesaemia).
Contact APHA if suspicious.
PME.
Pathogenesis of brain abscess?
Either originates from:
- dehorning sinusitis.
- haematogenous spread from another site of infection (e.g. lameness).
Typically gram +ve anaerobes.
Abscess development usually slower in onset than acute meningoencephalitis.
Brain abscess clinical signs?
Location determines signs.
Cranial nerve deficits.
Head-pressing.
Depression.
Central blindness.
