Antiparasitic practices in Portuguese animal shelters: A survey of veterinarians

Animal shelters often operate under significant resource constraints while caring for large populations of dogs and cats, many of whom are affected by parasitic infections that impact animal health and pose zoonotic risks. These limitations hinder the implementation of standardized, evidence-based parasite control protocols. This study surveyed veterinarians working in Portuguese shelters to describe current antiparasitic treatment practices and identify key limitations. A structured questionnaire was distributed to veterinarians in shelters or kennels affiliated with ICBAS, University of Porto, collecting data on animal populations, location, diagnostic testing, and antiparasitic drug use. A total of 41 responses were analysed. Additionally, a cost analysis was performed using 2024 wholesale antiparasitic treatment prices, based on average weights (20 kg dogs, 5 kg cats). Commercially available products were reviewed for active ingredients, target parasites, and cost per treatment. Descriptive statistics were used to summarize responses; no inferential analyses were performed given the limited sample size. Ectoparasiticides were the most frequently used treatments, followed by broad-spectrum nematocides and cestocides. Only 12% of shelters reported conducting diagnostic testing prior to treatment. Drug selection was primarily influenced by cost and perceived efficacy. Commonly used compounds included praziquantel, pyrantel, fipronil, fenbendazole, and milbemycin oxime, several of which have reported resistance in parasite populations. Treatment costs ranged from €0.82 to €219 per dose for 20 kg dogs and €0.73 to €34.84 for 5 kg cats. The limited use of diagnostics and reliance on broad-spectrum drugs reflect a reactive rather than preventative approach. Findings underscore the need for improved diagnostic protocols and strategic drug selection to enhance parasite control and animal welfare.