Asymmetrical focal neurological deficits in dogs and cats with naturally occurring tick paralysis (Ixodes holocyclus): 27 cases (1999-2006).
OBJECTIVE
To describe basic epidemiological features, clinical characteristics and outcomes of asymmetrical focal neurological deficits identified in dogs and cats with naturally occurring tick paralysis (Ixodes holocyclus).


METHODS
A retrospective study.


METHODS
Computer records were reviewed for all dogs and cats treated for tick paralysis between July 1999 and June 2006 at a suburban veterinary hospital in Newcastle, New South Wales.


RESULTS
Neurological deficits were identified in 17/197 dogs and 10/89 cats and included unilateral facial paralysis (14 dogs; 2 cats), anisocoria (4 dogs; 7 cats), unilateral loss of the cutaneous trunci reflex (1 dog; 1 cat) and Horner's syndrome in 2 cats with anisocoria. Occurrence of deficits was not linked to season, severity of tick paralysis, breed, age, sex or body weight. With facial paralysis and anisocoria, the site of tick attachment was invariably on the head or neck and always ipsilateral to the facial paralysis. By contrast, with anisocoria alone, no consistent relationship was noted between any one pupillary dimension and the side of tick attachment. With cutaneous trunci deficits the site of tick attachment was the ipsilateral caudal axilla. Compared with recovery times from generalised signs of tick paralysis, those for facial paralysis were significantly longer (days to weeks; P < 0.001), those for anisocoria showed no significant difference (P = 0.25) and those for cutaneous trunci deficits lagged by 6 and 7 days.


CONCLUSIONS
Asymmetrical focal neurological deficits are a consistent finding in a proportion of dogs and cats with naturally occurring tick paralysis due to I. holocylcus.
Holland
C T
CT
ctholland@ava.com.au
D000818:Animals; D015875:Anisocoria / Q000469:parasitology / Q000473:pathology / Q000662:veterinary*; D002371:Cat Diseases / Q000469:parasitology / Q000473:pathology*; D002415:Cats; D004283:Dog Diseases / Q000469:parasitology / Q000473:pathology*; D004285:Dogs; D005158:Facial Paralysis / Q000469:parasitology / Q000473:pathology / Q000662:veterinary*; D005260:Female; D018884:Ixodes; D008297:Male; D012189:Retrospective Studies; D012307:Risk Factors; D012621:Seasons; D013985:Tick Paralysis / Q000473:pathology / Q000662:veterinary*