Screening of gastrointestinal parasites of dogs from municipal kennels in Portugal

Abstract text

Introduction: Gastrointestinal parasites (GIP) are frequently reported in dogs worldwide, some of which are potentially zoonotic. Stray and shelter dogs are more prone to carry and spread GIP, but their prophylactic or therapeutical control is generally unknown. In Portugal, municipal kennels are facilities that shelter stray animals, but routine coprological analyses are rarely performed upon animal admission. Objectives: We performed a nationwide screening of GIP in dogs at municipal kennels and investigated the underlying potential causal factors. Materials & Methods: Between November 2021-October 2022, 355 dog stool samples were collected in several municipal kennels in Portugal, and then processed with the Mini-FLOTAC technique, using zinc sulphate flotation solution. The influence of animal- and kennel-related variables in parasite presence was assessed by Fisher's exact tests, with 95% significance. Results: Approximately 17% (59/355) of the samples were GIP-positive. Trichuris sp. (20/355), Toxocaridae (19/355), Ancylostomatidae (13/355), and Cystoisospora sp. (8/355) were the most frequently observed parasites. Most of the positive samples (53/59) had more than 10 eggs or oocysts per gram. The results revealed that the region and number of dogs housed in kennels were significantly associated with the presence of Ancylostomatidae (p< 0.001 and p=0.013, respectively) and Trichuris sp. (p=0.04 and p=0.03, respectively). Also, season was significantly associated with the presence of Ancylostomatidae eggs (p=0.004), while stool consistency and dogs' age range were significantly associated with Toxocaridae eggs (p=0.008 and p=0.049, respectively). Conclusion: To the best of our knowledge, this is the first nationwide screening of GIP in shelter dogs. The low overall GIP prevalence suggests that the internal deworming protocols in the assessed kennels are generally effective, with all of them deworming dogs internally upon admission, contributing to explain these results. However, our study also highlights the importance of considering several factors when establishing internal deworming protocols, including the intervention region encompassed by the kennel, the number of dogs housed and their age. Funding: Strategic Funding from FCT to cE3c (UIDB/00329/2020), CHANGE (LA/P/0121/2020), CIISA/FMV (UIDB/00276/2020), AL4AnimalS (LA/P/0059/2020), and to PL (2021.09447.BD), JL (2020.09037.BD) and ML (UI/BD/152818/2022), is gratefully acknowledged.