Comparison of conventional coproscopical, methods and commercial coproantigen ELISA kits for the detection of Giardia and Cryptosporidium infections in dogs and cats

Faecal samples of 270 dogs and 100 cats from 3 animal shelters in Germany were comparatively examined using conventional coproscopical methods and commercial coproantigen ELISA kits for the detection of Giardia and Cryptosporidium infections. Giardia cysts were found in 9.5% and 0% of the faecal samples in dogs and cats, respectively, examined once using the ZnCl2-NaCl flotation. However, the Giardia coproantigen ELISA (ProSpecT(R) Giardia Microplate Assay) was positive in 29.5% and 22.4% of the samples from dogs and cats, respectively. Direct faecal smears stained with carbol fuchsin showed Cryptosporidium oocysts in one dog (0.4%) and one cat (1%). In contrast, the Cryptosporidium coproantigen ELISA (ProSpecT(R) Cryptosporidium Microplate Assay) reacted positively in 23% of the samples from dogs and 30% of the samples from cats. Both coproantigen ELISAs were more often positive in coproscopically Giordia-negative canine faecal samples that contained Isospora burrowsi/ohioensis oocysts than in faecal samples without any parasite stage. Possible reasons for these observations are discussed.