Long QT syndrome in dogs with tick toxicity (Ixodes holocyclus).
OBJECTIVE
To evaluate cardiac electrical function in dogs with tick toxicity.


METHODS
A prospective clinical investigation of 39 client-owned dogs treated for naturally occurring tick toxicity.


METHODS
An ECG was performed on each dog on several occasions; at admission to hospital with tick toxicity, 24 h later, at discharge from hospital when clinically normal and approximately 12 months later.


RESULTS
The mean QT interval corrected for heart rate (QTc) was prolonged at admission, 24 h and at discharge compared to the QTc measured 12 months later. T wave morphology was altered in dogs at admission. All other parameters were within normal limits.


CONCLUSIONS
The prolonged QTc interval and altered T wave morphology of dogs with tick toxicity reflects delayed cardiac repolarisation and is comparable with long QT syndrome (LQTS) in people who are predisposed to polymorphic ventricular tachycardia and sudden death. Resolution of ECG changes lagged behind clinical recovery.
Campbell
F E
FE
School of Veterinary Science, The University of Queensland, Queensland 4072.
Atwell
R B
RB
D000818:Animals; D001145:Arrhythmias, Cardiac / Q000209:etiology / Q000503:physiopathology / Q000662:veterinary*; D001947:Breeding; D004283:Dog Diseases / Q000453:epidemiology / Q000503:physiopathology*; D004285:Dogs; D004562:Electrocardiography / Q000662:veterinary; D005260:Female; D006339:Heart Rate; D018884:Ixodes; D008297:Male; D011446:Prospective Studies; D011793:Queensland / Q000453:epidemiology; D013986:Tick Toxicoses / Q000150:complications / Q000503:physiopathology / Q000662:veterinary*