Occurrence of strongyloidiasis in sheltered dogs from Southern Italy

Strongyloidiasis caused by Strongyloides stercoralis is a zoonotic disease potentially fatal to dogs and humans. Data on the epidemiology of canine strongyloidasis is scant, likely because of inadeguate diagnostics currently employed for the detection of dog infections by Strongyloides. To our knowledge, polymerase chain reaction (PCR) has not been applied to dogs either for epidemiological surveys or for comparison of diagnostic methods. We reported the clinical presentation and outcome of 5 dogs with S. stercoralis infection diagnosed by the detection of larvae in fecal samples. In addition, a qPCR routinely used in human medicine has been used for the diagnosis of canine strongyloidasis. Dogs were hosted in a single shelter in the province of Bari in which a history of diarrhea, weight loss, reduced appetite and respiratory symptoms was reported. The five dogs were positive for S. stercoralis by coproscopy on direct faecal smears and via the Baermann method. All of them, but one, were treated with fenbendazole (Panacur®, Intervet, Animal Health, 50mg/kg, PO daily for five days), or with a combination of fenbendazole and moxidectin plus imidacloprid spot-on (Im/Mox; Advocate® spot-on, Bayer). Following treatment all dogs resulted negative at Baermann in at least 12 days. Anyway, failure of treatment was documented in two dogs by means of reverted Baermann positive results throughout the study and/or post-mortem detection of adult parasites. PCR was positive in all pre-treatment fecal samples and in all fecal debris. One dog resulted negative at Baermann test one week after treatment and showed positive PCR results. This study documents, for the first time, the presence of S. stercoralis infection in sheltered dogs from southern Italy. Treatment with fenbendazole alone or combined with moxidectin plus imidacloprid could be not effective against the infection. PCR routinely used for S. stercoralis diagnosis in humans showed good performance in dog and could be important not only for diagnostic purpose but also to evaluate the efficacy of treatments. Finally, data indicate that S. stercoralis infection may represent an issue for sheltered animals and a potential risk for personnel working in the large number of municipal shelters present in Southern European countries.