Reduced incidence of tick paralysis cases in dogs and cats at two emergency clinics in South-East Queensland since 2015: new generation prophylactics as possible explanatory variables.

Abstract

This study aimed to determine the incidence of canine and feline tick paralysis cases presenting to two veterinary emergency hospitals before and after the introduction of new generation prophylactic acaricides. This was a retrospective study, investigating the number of tick paralysis cases presenting to two emergency and critical care veterinary hospitals in South-East Queensland, from 2008 to 2021. A total of 10,914 dogs and 3696 cats were included over the course of the study. To assess if the introduction of new generation prophylactics in 2015 has coincided with any variation in case numbers, data for each species were analysed graphically and numerically in the first instance, then interrupted time series analyses were performed for the dog and cat data independently. Accounting for seasonal and climatic variation, we estimated a 54.8% reduction in dog (95% CI 45.3%-62.7%) and 44% reduction in cat (95% CI 19.5%-46%) tick paralysis cases presenting to these two clinics. This reduction corresponded with the timing of new generation prophylactic agents being introduced, including isoxazolines and imidacloprid/flumethrin impregnated collars. In the population studied, a significant reduction in the incidence of tick paralysis cases treated by veterinarians has occurred from 2015 onwards and was found to be associated with the timing of the release of new generation acaricidal products.