A national survey of Ixodidae ticks on privately owned dogs in Italy.

Background: The geographical distribution of ticks on companion animals needs to be monitored to develop and plan effective control measures, as suggested by the European Scientific Counsel on Companion Animal Parasites. The aim of this study was to conduct the first Italian national survey of tick distribution on privately owned dogs.

Methods: The study was performed over 20 months (February 2016 - September 2017) and involved 153 veterinary practices in 64 different provinces covering 17/20 (85%) Italian regions. Participating practitioners were asked to examine five different dogs per month at random and complete a questionnaire for each dog. Differences in tick infestation associated with: sex, age and hair length (long and short); the dog's habitat (indoor or outdoor/kennel); and the dog's environment (urban or rural/sylvatic) were evaluated. The attachment site of ticks on the dog was also recorded. Acaricide efficacy was evaluated for the subset of dogs for which complete information on product used, date of sampling and date of last ectoparasiticide treatment was available.

Results: Of the 3026 dogs examined, 1383 (45.7%) were carrying at least one tick. Overall, 2439 tick samples were collected and a total of 14 tick species identified. Rhipicephalus sanguineus group were the most predominant ticks (63.6%), followed by Ixodes ricinus (30.6%) and I. hexagonus (5.6%). Twenty-four dogs had mixed tick infestations. Long-haired dogs had a higher tick infestation risk as did dogs with outdoor and rural/sylvatic lifestyles. Ticks were located on the head (37.4%), the neck (28.8%), the muzzle (15.5%) and the back (15.3%). A higher prevalence of Rhipicephalus was found in the interdigital spaces (10.8%) compared to Ixodes (0.2%). Finally, ectoparasiticide treatments were found significantly protective against tick infestation, especially orally administered formulations.

Conclusions: Privately owned dogs in Italy have a high prevalence (45.7%) of infestation with ixodid ticks and this risk varies by dog phenotype and lifestyle.