Comparison between natural infection by Cryptosporidium sp., Giardia sp. in dogs in two living situations in the West Zone of the municipality of Rio de Janeiro.

In order to compare natural infection by Cyptosporidium sp. and Giardia sp. in clinically healthy dogs living in two situations (animal shelter and household pets), we conducted 166 faecal exams using the technique of centrifugation-flotation in a sugar-saturated solution. Of the faecal samples, 94 came from shelter dogs and 72 from house pets. Eighty-two (49.4%) contained parasite eggs, cysts or oocysts. Of these, four (2.41%) contained Cryptosporidium sp. oocysts and 52 (31.33%) contained Giardia sp. cysts. There was no statistically significant difference between the origin of the dogs and Cryptosporidium sp. infection. Infection by Cryptosporidium sp. was not associated with the living conditions and sex. With respect to Giardia sp., we observed a statistically significant difference (p < 0.001) between the shelter dogs (45%) and the household pets 12.3%. There was no association of infection by Giardia sp. with age or sex.