Tick (Acari: Ixodidae) Paralysis in Dogs from Northern California: Acarological and Clinical Findings

Publisher Website
Google Scholar
Abstract
A 1-year investigation of all canine tick paralysis cases seen in 2 veterinary practices in the Grass Valley area of northern California incriminated Dermacentor variabilis and Ixodes pacificus (Acari: Ixodidae) in the etiology of 8 cases and 1 case, respectively. In 3 additional cases, dogs were infested concurrently with 1 or more feeding females of both tick species. A mean of 32.3 ticks (SD = 62.5, range = 3–222) per animal was recovered, 97.7% of which were D. variabilis adults. The prevalence (=percentage of hosts infested) was 100% for D. variabilis and 33% for I. pacificus, and the intensity (=mean number of parasites per host examined) was 31.6 for D. variabilis and 0.75 for I. pacificus. This is the 1st time that D. variabilis has been associated definitively with tick paralysis in dogs from California, and the 2nd time that I. pacificus has been incriminated. The disease was characterized clinically by a flaccid, ascending paresis normally unaccompanied by other signs. All dogs made a complete and rapid recovery within 8–48 h following removal of ticks. Cases were seen over a 45-day period during May and June.