Exotic animal neurology

Question 1

What is different about neuro exams in small mammals?

Answer 1

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

Question 2

What are the clinical signs of rabbits with peripheral vestibular disease?

Answer 2

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

Question 3

What are the clinical signs of rabbits with central vestibular disease?

Answer 3

depressed
reduced appetite
nystagmus with fast phase in any direction + changing with head position

can also have other CNS signs

Question 4

What are the likely ddx of a rabbit head tilt? (DAMNITV)

Answer 4

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

Question 5

What is E. cuniculi?

Answer 5

small obligate intracellular pathogen, microsporidium
mostly causes disease in rabbits but also dogs, cats, guinea pigs

potentially zoonotic! esp. in immunosuppressed

Question 6

Where are e. cuniculi found and how are they transmitted?

Answer 6

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

Question 7

Where does E. cuniculi cause clinical signs?

Answer 7

spore infects GI epithelium when ingested + travel via blood stream to target organs

mainly: kidney + CNS
also: lungs, liver, heart

Question 8

What are the clinical signs of E. cuniculi?

Answer 8

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

Question 9

How do we interpret results of E. cuniculi when serology IgM and IgG are negative but clinical signs?

Answer 9

unlikely to be EC

Question 10

How do we interpret results of E. cuniculi when serology is positive IgM +/- IgG with neuro signs?

Answer 10

active EC infection but may not be the cause of CS

Question 11

How do we interpret results of E. cuniculi if serology is negative IGM and positive IgG with neuro signs?

Answer 11

indicated exposure to EC
this persists months to years after exposure

Question 12

What tests other than serology can indicate E.cuniculi infection?

Answer 12

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

Question 13

What gives a definitive diagnosis of E. cuniculi?

Answer 13

gross PM changes in brain/kidney may be suggestive
histopath chnages in association with parasite spores
PCR testing tissue samples

Question 14

What is the tx for E. cuniculi?

Answer 14

Fenbendazole

CS don’t always resolve due to inflammatory changes

supportive tx: steroids? nsaids? symptomatic tx?

Question 15

How can we prevent E.cuniculi?

Answer 15

preventative course of fenbendazole
28day course on arrival when mixing new rabbits

Question 16

What is different in neuro exams for birds?

Answer 16

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?

Question 17

What is heavy metal toxicosis?

Answer 17

common acute neuro dz in birds
chronic exposure can also cause immunosuppression = secondary infections

Question 18

What is tx for heavy metal toxicosis?

Answer 18

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

Question 19

What diseases can avian bornavirus cause?

Answer 19

common in maccaws
cause of avian ganglioneuritis
proventricular dilation disease
lymphoplasmacytic ganglioneuritis
encephalomyelitis
progressive neuro dz
other

Question 20

What are clinical signs of avian ganglioneuritis?

Answer 20

insidious dz course
some birds show no CS
high mortality once CS present
weight loss
regurgitation
delayed crop emptying
undigested seed in faeces
etc

Question 21

How do we diagnose PDD?

Answer 21

CS
xray
barium series
PCR and serology for bornavirus
crop biopsy if GI signs

Question 22

What is tx for PDD?

Answer 22

palliative
pure cox2 NSAID to reduce infl.
- celecoxib IM, robenacoxib IM
meloxicam?
metoclopramide or cisapride may improve GI motility
nutritional support

Question 23

What is different about neuro exams in reptiles?

Answer 23

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)

Question 24

What is a common pathogen in young bearded dragons with neuro and +/- GI disease?

Answer 24

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

Question 25

What type of analgesia do we give to monitor lizards with ataxia due to osteoarthritis?

Answer 25

meloxicam
tramadol

Question 26

What are other consideration for neuro dz in lizards?

Answer 26

paramyxoviruses
bacterial
toxins
neoplasia
xanthomatosis especially in reproductive females