Neurological (Yr 4) Flashcards
what are the main localisations of brain lesions?
cerebellum
cerebrum
vestibular system
brainstem
what are the clinical signs of a diffuse cerebrum lesion?
altered mental state (depression, hyperexcitable…)
blindness
seizures
opisthotnus
what are some lesions that can diffusely effect the cerebrum?
bacterial meningitis
cerebrocortical necrosis
pregnancy toxaemia
what are the signs of local cerebrum lesions?
contralateral blindness
circling
proprioceptive deficits
what are some causes of local cerebrum disease?
GID cysts (Taenia multiceps)
brain abscess
trauma
what are the clinical signs of cerebellum lesions?
altered head carriage
ataxia/wide based stance (balance)
dysmetria/hypermetria
intention tremor and nystagmus
what can cause cerebellar disease?
congenital - cerebellar hypoplasia (border disease virus)
what are some clinical signs of vestibular disease?
head tilt (to affected side)
ataxia (loss of balance)
circling, falling, rolling
spontaneous nystagmus
what are some clinical signs of brainstem disease?
depression (ARAS affected)
cranial nerve deficits
ipsilateral hemiparesis
what is the main condition of sheep that affects the brainstem?
listeriosis
what are some lesions that can affect the spinal cord?
spinal abscess (tick pyaemia)
wobblers syndrome (texels)
trauma
congenital abnormalities
what are the main neurological diseases affecting young lambs (<3 months old)?
border disease
congential swayback
drunken lamb syndrome and lamb nephrosis
bacterial meningitis
tetanus
trauma
spinal abscess
louping ill
how do lambs with border disease present?
hair shakers (tremors with strong hair coat)
how do lamb with congenital swayback present?
ataxic
what is the cause of congenital swayback?
copper deficiency
how will lambs with bacterial meningitis present?
collapsed
how are spinal abscesses treated?
dexamethasone and penicillin
what cause louping ill?
flavivirus
what spreads louping ill?
ticks
what are the clinical signs of louping ill?
head pressing
trembling/tremors/lip twitching
nystagmus
louping gait (moving front/back legs in unison)
how can you control louping ill?
vaccination
(gain immunity with age)
what are the main neurological disease affecting older lambs (>3 months)?
cerebrocortical necrosis (CCN)
listeriosis
gid
louping ill
trauma
what causes CCN?
vitamin B1 (thiamine) deficiency
caused by a change such as diet (weaning), worming…
what age sheep is CCN typically seen in?
rapidly growing lambs (2-6 months old)
what are the clinical signs of CCN?
dull, disorientated, recumbency
blind
tremors
opisthotonus
convulsions (poor prognosis)
how is CCN treated?
vitamin B1 (every 12 hours for 3 days)
supportive - quiet housing, diet…
what causes listeriosis?
Listeria monocytogenes
what are the clinical signs of listeriosis?
anorexia, depression
unilateral hemiparesis
trigeminal nerve paralysis (salivation, feed impacted in cheeks)
facial paralysis (drooped ear, lowered eyelid…)
what are the two nerves commonly effected by listeriosis?
trigeminal and facial
how can listeriosis be treated?
(catch early!!)
benzylpenicillin IV or procaine penicillin IM
dexamethasone
(5 days course of penicillin)
what causes did?
Taenia multiceps(not very common now)
what are the clinical signs of gid cysts?
circling
unilateral blindness (contralateral side)
head tile
skull softening
(gradual onset)
how can gid cysts be controlled?
worm dogs with praziquantel every 6 weeks
keep dogs away from sheep carcasses
what is the main differential for vestibular disease?
otitis media (Pasturella, Streptococcus…)
what are the neurological disease seen in sheep?
cervical subluxation (rams fighting) and trauma
listeriosis
metabolic disease (pregnancy toxaemia, hypocalcaemia, hypomagnesaemia)
brain abscess, gid cyst
wobblers
scrapie
what are the typical signs of hypomagnesaemia?
staggers and hyperaethesia
what are the typical signs of hypocalcaemia?
collapsed, bloated, flaccid paralysis
how can pregnancy toxaemia be diagnosed?
beta hydroxbutrate and clinical signs
when does hypocalcaemia typically occur in sheep?
before lambing
when is hypomagnesaemia typically seen in sheep?
after lambing usually when rearing twins (stress and milk drain as no magnesium store)
