Canine giardiosis in Sardinia Island, Italy: prevalence, molecular characterization, and risk factors

The flagellate protozoan Giardia duodenalis causes infection in humans and in various animals. Eight distinct assemblages (A-H) have been identified within G. duodenalis; assemblages A and B are those specific to humans and animals, and assemblages C to H are restricted to animal hosts.

The present study estimated the prevalence of G. duodenalis assemblages in dogs living in the Sardinia region and evaluated the related risk factors. Individual fecal samples were collected from 655 dogs between January 2007 and December 2010, and a form was filled out for each animal to analyze historic data that were available at the time of sampling. Fecal samples were subjected to microscopic and genetic investigations.

Cysts of G. duodenalis were found in 172 (26.3%) samples, with significant values in puppies between three and nine months of age, and in kennelled and hunting dogs. The molecular characterization showed the presence of assemblages D (49%), C (36.1%), and subtype A2 (4.2%).

The present survey contributes to the knowledge of the occurrence of canine giardiosis in Italy in a region with a high number of dogs and numerous animal movements, which is especially relevant for touristic reasons.