Neurological disease of cattle Flashcards
What part of the CNS is responsible for conscious functions?
Brain
What part of the CNS is responsible for cranial nerve functions and breathing?
Brainstem and cranial nerves
What part of the CNS is responsible for unconscious control of proprioceptive functions and coordination/smoothing of movements?
Cerebellum
What part of the CNS is responsible for limb movement and strength?
Spinal cord
Carrying limbs suggests what type of problem - orthopaedic or neurological?
Orthopaedic
Dragging limbs suggests what type of problem - orthopaedic or neurological?
Neurological
Shortened stride/step suggests what type of problem - orthopaedic or neurological?
Orthopaedic
Increased step length suggests what type of problem - orthopaedic or neurological?
Neurological
Circling usually indicates a lesion in what part of the CNS?
Brain
Asymmetrical cortex lesion
Falling over usually indicates a problem in what part of the CNS?
Cerebellum
Head-pressing normally indicates what problem?
Increased cranial pressure
Or encephalitis
What is the difference between tremors and spasms?
Tremors - rapid contractions of muscle groups AND their antagonists
Spasm - sudden intense contractions of muscle groups
What is extended muscle cramp called?
Tetanus
What is spasticity? What lesions does it occur with?
Increased muscle tone
Brain stem or spinal cord lesions
What is the difference between paresis and paralysis?
Paresis - still able to move (but weakened movements)
Paralysis - unable to move
What can be used to percuss the head, vertebrae and pelvis?
Finger - head
Fist - vertebrae in neck
Percussion hammer -rest of vertebrae and pelvis
If blindness occurs due to a lesion in the cortex, how are the menace response and iris reflexes affected?
No menace response
Iris reflex normal
What is the palate reflex?
Pressing palate
Normal response is palate should open
What nerve does the palate reflex and jaw drop test?
Trigeminal nerve
If a cow cannot close one eyelid, has a lower lip hanging and cannot close one side of their mouth, what cranial nerve is most likely to be affected?
Facial nerve
What is the anal reflex?
Thermometer in rectum - should case contraction of external anal sphincter
The patella reflex and radoiocarpal extensor reflex should be checked in what age cows?
Calves
What is the scrotal reflex?
Touching scrotal skin
Would expect skin to wrinkle
What should happen if you pinch a cow’s skin between their claws?
Should bend leg
When a cow’s head is moved, what should happen in regards to their eye movement?
Move opposite way
What is the conscious and proprioceptive neurological test?
Walk towards small obstacle
Conscious - should lift leg
Unconscious - wearing a blindfold, should lift leg when arrives near obstacle
When getting up, do cattle get onto their forelimbs or hindlimb first?
Hindlimbs
Are brain tumours acute or chronic?
Chronic
What clinical signs would you expect to see with a cortical lesion?
Ataxia Proprioceptive deficits Blindness Circling Nystagmus Changes in behaviour Head pressing (raised ICP, encephalitis)
What clinical signs would you expect to cerebellar brain lesion?
Imbalanced Wide based stance Head tilt Dysmetria Nystagmus Hyperaesthesia
What is the most common cause of meningitis in calves? What age cows are affected?
1 week old calves
Lack of colostrum
A 1 week old calve is head pressing. What would you expect to be the most likely diagnosis?
Meningitis
What is the treatment and prognosis for meningitis?
IV antibiotics
Dexamethasone
(Poor prognosis)
Penicillin is ineffective to what pathogens?
Gram negative bacteria
Do not use if suspected E. coli, Klebsiella, Salmonella
Brain abscesses are mostly caused by what pathogen?
Arcanobacterium pyogenes
With a brain abscess, is the head tilt towards are away from the lesion?
Head tilt TOWARDS lesion
What is hydrocephalus also known as? What is it?
Occasional acute cortical disease
Failure of CSF drainage caused increased ICP
What breeds are predisposed to hydrocephalus (occasional acute cortical disease)?
Holstein
Jersey
Fresian
Guernsey
What are the clinical signs of hydrocephalus?
Domed cranium
Diffuse cerebral signs - inc head pressing
What causes CCN?
Thiamine (B1) deficiency
Causes necrosis of the GREY matter
What age is most commonly affected by CCN?
6-18 months old
Young cattle
What are some clinical signs you would expect to see with CCN?
Star-gazing
Blindness
Diarrhoea
How is CCN diagnosed?
History, clin signs, response to treatent
Blood thiaminase assay
Post mortem - yellow patches, fluorescence under UV light
On a post-mortem of a cow with CCN, what brain changes would you expect to see?
Yellow pigment - lipofuscin
Fluorescence under UV light
How is CCN treated in cattle?
Thiamine (B1)
Corticosteroids
Thiamine supplemented ration, introduce concentrates slowly
Which age of cattle is lead poisoning most common in?
Young - due to curious nature
Lead poisoning in cows causes what CNS problem?
ACUTE encephalopathy
Cerebral and GI signs
How is lead poisoning in cattle treated?
Pentobarbitone - control seizures
Chelate lead
Thiamine
Oral magnesium sulphate (precipitates lead from GIT)
Why may you consider euthanasia over treatment in the case of lead poisoning?
Poor prognosis
6-7 months to return to milk/meat being suitable for consumption (contact APHA)
What causes nervous ketosis?
Negative energy balance
Causes rapidly mobilising of adipose tissue - nonsterified fatty acids in blood
How long and often do the signs of nervous ketosis last?
Last 1-2 hours
Occur at 10 hourly intervals
How is nervous ketosis treated?
Dextrose IV
Propylene glycol (used to treat ketosis)
Corticosteroids
Hypomagnesaemia is especially seen in which type of cattle?
Pastured lactating beef cows on pasture
Magnesium excreted in milk - at risk if calved within past few months
What are the causes of salt poisoning? What CNS problem does it cause?
Too much salt or water deprivation
Sodium deposition in the brain - may increased intracranial pressure
How is salt poisoning treated?
Rehydrate, then use hypertonic saline (otherwise increase ICP)
What is Pseudorabies also known as?
Aujezsky’s, Mad itch
For pseudorabies to be suspected in cattle, which other species must they have been in contact with?
Pigs
Which of the following suspected disease requires APHA to be contacted: rabies, pseudorabies or both?
Both
Is Pseudorabies often fatal?
Yes - within 2 days
BSE (Mad cow disease) causes prion protein accumulation within what part of the CNS? What is it associated with?
Neurones
Foodstuff containing meat and bone meal
Is BSE notifiable?
Yes
How is BSE diagnosed?
Post-mortem only (histopath)
No test for live animals as long incubation period only
Hypovitaminosis A is associated with what based diets?
Straw or cereal based
What is the most obvious clinical signs associated with hypovitaminosis A?
Blindness
What is the treatment for hypovitaminosis A? Is the response to treatment usually good?
Daily vitamin A
Yes - response good within 48 hrs, even in fitting animals
Cerebellar hypoplasia can be congenital or acquired. What breeds is it congenital in?
Holstein, Guernsey, Shorthorn, Herefrods, Ayrshire
Cerebellar hypoplasia can be congenital or acquired. What disease causes acquired cerebellar hypoplasia?
BVD
Listeriosis is caused by Listeria monocytogenes. Is it an environmental or contagious pathogen? What is associated with?
Environmental
Poor quality silage, fermentation, soil contamination
Listeriosis infection starts in conjunctiva, face and mouth and travels to the brainstem via which nerve?
Trigeminal
What affect does listeriosis have on the CNS?
Causes micro abscesses
In brainstem, cerebellum and spinal cord
May progress to meningioencephalitis
What are some classic clinical signs of listeriosis?
Protruding tongue
Facial paralysis - 3rd eyelid prolapse
Ptosis, drooping of ear on one side
Loss of lip/cheek muscle town - difficulty eating, saliva
How is listeriosis commonly treated?
Remove underlying cause
(silage)
High doses of penicillin or oxytetracycline
Spinal factures are most common in what age calves?
3-6 months old
What are spinal abscesses usually secondary to in cattle?
Osteomyleitis of vertebrae
Give examples of possible bacteria that may be present in a spinal abscess
Arcanobacterium progenies
Staph aureus
Pasteruella haemolytica
Fusobacterium necrophorum
Spastic paresis is most often seen in what muscle group?
Extensor muscles of the hindlimbs
What age cows are usually affected by spastic paresis?
Calves - few weeks to 6 months old
What are the clinical signs of spastic paresis in cattle?
Asymmetric spasticity
Hypertonia of extensor HL muscles (continuous when standing, not when laying down) extended hock
XS tone of gastrocnemius
Walking with pendulum motion
How is spastic paresis treated?
Neurectomy of tibial nerve rootlets innervating gastrocnemius
If bilateral leave 6-10 wks between surgeries
What causes tetanus in cattle?
Exotoxins produced by Clostridium tetani
Spores enter wounds
What are the clinical signs of tetanus in cattle?
Extended head posture
Extensive facial tone
Stiff, raised tail
Legs rigidly extended
How is tetanus prevented and treated?
Prevented by vaccination
Tx: antitoxin (if early), high doses of penicillin, muscle relaxants?
Botulism (Clostridium botulinum) is often associated with what?
Poultry waste/litter/carcasses
In pasture or feed
What are the clinical signs of botulism?
Anorexia, mydriasis
Xs drooling, drooping tongue
Ruminal bloat and decrease mobility
Respiratory failure - death
What is the prognosis of botulism in cattle? How is it treated?
Prognosis poor - may recover if caught early
Supportive Tx, purgatives to remove toxins, fluids
What nerve is commonly damaged by XS foetal pressure following dystocia (especially in heifers)?
Obturator nerve
What is the main clinical signs of obturator neuropathies in cattle? How is this treated?
Unable to adduct limbs - splits
treatment with chained HLs, soft bedding, corticosteroids
What nerve is commonly damaged due to a falling or recumbent cow?
Perineal branch of sciatic nerve or sciatic nerve
Self-cures, cast-fetlock to prevent self trauma
