Exotic animal neurology Flashcards
What is different about neuro exams in small mammals?
majority are prey= can freeze
presence of reflex/response is reliable but absence isn’t
usually no menace response
video of behaviour at home can be useful
What are the clinical signs of rabbits with peripheral vestibular disease?
usually BAR
may have facial nerve deficits or horner’s
nystagmus with fast phase away from lesion, no change with head position
usually concurrent dz of external ear dectected on PE
What are the clinical signs of rabbits with central vestibular disease?
depressed
reduced appetite
nystagmus with fast phase in any direction + changing with head position
can also have other CNS signs
What are the likely ddx of a rabbit head tilt? (DAMNITV)
degen: could be vestibular but not likely if sudden onset or young
anomaly: none
metab: none
neoplasia: vestibular or peripheral signs but not likely if young
inflamm/infect: BACT ++, some viral, some parasites, Encephalitozooon cuniculi ++
trauma/toxins: peripheral or vestibular signs but less likely without trauma or otoxic drugs
vascular: could have ventral vestibular signs but uncommon
What is E. cuniculi?
small obligate intracellular pathogen, microsporidium
mostly causes disease in rabbits but also dogs, cats, guinea pigs
potentially zoonotic! esp. in immunosuppressed
Where are e. cuniculi found and how are they transmitted?
wild rabbits, some wild rodents and foxes
seroprevalence of 50+% in clinically healthy rabbits in UK
spores are shed intermittently in the urine and ingesyed by other animals, inhalation and in-utero transmission also possible
Where does E. cuniculi cause clinical signs?
spore infects GI epithelium when ingested + travel via blood stream to target organs
mainly: kidney + CNS
also: lungs, liver, heart
What are the clinical signs of E. cuniculi?
CS due to cell rupture and granulomatous inflammation
neuro signs most common especially a head tilt
urinary incontinence and urine scalding
weight loss
anorexia
lethargy
ocular lesions (if contracted in utero)
sudden death
How do we interpret results of E. cuniculi when serology IgM and IgG are negative but clinical signs?
unlikely to be EC
How do we interpret results of E. cuniculi when serology is positive IgM +/- IgG with neuro signs?
active EC infection but may not be the cause of CS
How do we interpret results of E. cuniculi if serology is negative IGM and positive IgG with neuro signs?
indicated exposure to EC
this persists months to years after exposure
What tests other than serology can indicate E.cuniculi infection?
No one test can provide definitive diagnosis of EC in a live rabbit
haem, biochem, urinalysis VS renal function
PCR testing of urine/faeces/CSF but depends on stage of infection/spore burden
PCR testing of lens material
Skull CT to rule out otitis media
What gives a definitive diagnosis of E. cuniculi?
gross PM changes in brain/kidney may be suggestive
histopath chnages in association with parasite spores
PCR testing tissue samples
What is the tx for E. cuniculi?
Fenbendazole
CS don’t always resolve due to inflammatory changes
supportive tx: steroids? nsaids? symptomatic tx?
How can we prevent E.cuniculi?
preventative course of fenbendazole
28day course on arrival when mixing new rabbits
What is different in neuro exams for birds?
enhanced vision
iris has straited muscle = voluntary control
no consensual pupillary reflex
CS of neuro dz often generalised
can mask illness signs in the clinic
assess mentation, gait/position, seizures?
What is heavy metal toxicosis?
common acute neuro dz in birds
chronic exposure can also cause immunosuppression = secondary infections
What is tx for heavy metal toxicosis?
chelation: calcium edetate or penicillamine
supportive care
xrays 30days post tx to ensure ventricular FB have passed through
psyllium tx to aid passage
gizzard flush
ventriculotomy
What diseases can avian bornavirus cause?
common in maccaws
cause of avian ganglioneuritis
proventricular dilation disease
lymphoplasmacytic ganglioneuritis
encephalomyelitis
progressive neuro dz
other
What are clinical signs of avian ganglioneuritis?
insidious dz course
some birds show no CS
high mortality once CS present
weight loss
regurgitation
delayed crop emptying
undigested seed in faeces
etc
How do we diagnose PDD?
CS
xray
barium series
PCR and serology for bornavirus
crop biopsy if GI signs
What is tx for PDD?
palliative
pure cox2 NSAID to reduce infl.
- celecoxib IM, robenacoxib IM
meloxicam?
metoclopramide or cisapride may improve GI motility
nutritional support
What is different about neuro exams in reptiles?
big variation between species
iris contains skeletal muscle = some voluntary control
some species have fused spectacle instead of eyelids
locomotor centres within spinal cord so a degree of functional autonomy from brain
ectothermic animals! exam performed at POTZ (invalid results when cold)
What is a common pathogen in young bearded dragons with neuro and +/- GI disease?
adenovirus
common prevalence in pet population
diagnose on PCR of oral/cloacal swab
positive results could be incidental and not cause of problem presented with
