Cryptosporidium in Dogs and Cats

What are cryptosporidia?

Cryptosporidia are single-celled intestinal parasites belonging to the coccidia phylum that colonize the brush border of intestinal epithelial cells. In small animals, the host-adapted species Cryptosporidium canis (dog) and Cryptosporidium felis (cat). The environmentally resistant oocysts are infectious as soon as they are excreted. The pathogen is not enteroinvasive: it attaches apically to the enterocytes without penetrating into deeper tissue layers.

Transmission and Spread

Transmission occurs via the fecal-oral route through the ingestion of oocysts from a contaminated environment, water, or food. Cryptosporidia are found worldwide; prevalence in dogs and cats is comparatively low, and even clinically unremarkable animals can shed oocysts. The zoonotic potential of C. canis and C. felis is low and primarily affects immunocompromised individuals.

Symptoms and Course of Cryptosporidiosis

Infections in immunocompetent animals are often subclinical or self-limiting. They become clinically significant primarily in young animals, immunocompromised animals, or in the context of mixed infections. In these cases, watery, sometimes chronic diarrhea occurs, accompanied by malabsorption and weight loss. Since the pathogen is not enteroinvasive, the feces usually contain no blood, provided there is no concomitant infection.

Detecting Cryptosporidium

It is not clinically possible to determine the etiology of the diarrhea. The very small oocysts are difficult to visualize under a microscope, which is why antigen detection in feces is important. Given that Cryptosporidium is excreted even in the absence of disease, a positive result must always be evaluated within the clinical context and in conjunction with other findings.

Rapid Cryptosporidium Test from Feces

The Fassisi® CryGiDia and Fassisi® CryGiDia MPX tests detect Cryptosporidium parvum and Giardia duodenalis in feces and aid in the diagnosis of diarrheal diseases in dogs and cats—including mixed infections—using a single sample.

Sources for the information provided.