Infestation patterns of Ixodes scapularis and Dermacentor variabilis on dogs and cats across Canada.

Abstract

Due to recent climatic and land use changes, Canada has experienced changes in tick populations, leading to an increased risk of tick bites and tick-borne pathogen exposure, especially in eastern Canada. Preventative recommendations for companion animals from veterinary professionals include regular use of tick prevention products and tick checks. Tick checks, specifically, should target regions of an animal's body which are deemed to be high risk for tick attachment. However, tick species-specific infestation patterns on dogs and cats are largely understudied, and additional research is needed to help guide targeted tick checks. The objective of this study was to identify tick species-specific infestation patterns on dogs and cats. Ticks were collected for one year (April 2019 -March 2020) from 94 veterinary clinics across Canada as part of the Canadian Pet Tick Survey. All ticks were identified to species, and data on the location of tick attachment were ascertained with each submission. To examine the association between location of attachment (outcome) and tick species (explanatory variable), specifically Ixodes scapularis and Dermacentor variabilis, mixed effects univariable models were built. Two thousand three hundred and six submissions were received from 1925 dogs and 381 cats across Canada. Of these submissions, 1377 comprised Ixodes scapularis, and 620 comprised Dermacentor variabilis. Clear tick species-specific infestation patterns for dogs were present, with I. scapularis being significantly more likely to be found on the shoulders, and D. variabilis more likely to be found on the ears and neck. Dermacentor variabilis was more likely to be found on the cranial aspect of cats' limbs, compared to I. scapularis. Up-to-date information on infestation patterns can be used to inform veterinary professionals and pet owners of common attachment sites based on established ticks in their region and thus conduct targeted tick checks.