Cryptosporidium in Dogs

Cryptosporidium are a protozoan parasite that affects rodents, dogs, calves, humans and cats. Infection with this parasites is known as cryptosporidiosis. It can be a primary disease, or it can occur as a secondary infection in dogs with weakened immune systems. Cryptosporidiosis usually occurs in dogs younger than six months of age.

How Cryptosporidiosis Affects Your Dog

Cryptosporidium protozoa are very highly infectious. They affect your dog's gastrointestinal tract and may cause GI symptoms. Many dogs recover spontaneously from infestation by this parasite, and show no symptoms. Others may show only mild diarrhea.

In dogs with weakened immune systems, cryptosporidiosis can cause chronic diarrhea and dehydration. In immunocompromised dogs, this parasite can be life threatening.

Symptoms and Diagnosis of Cryptosporidium Infection

The primary symptoms of cryptosporidium infection are watery diarrhea, weight loss and poor appetite. Your dog's symptoms will vary in severity depending on the strength of his immune system. Many dogs never show symptoms of cryptosporidiosis at all, even though vets believe most dogs are exposed to this protozoa at some point in their lives.

Your vet can diagnose this type of infection with a fecal exam, intestinal biopsy and serology tests. Serology tests can help identify antibodies against this protozoa in your dog's blood; that means he's been exposed to the parasite, but may not be currently infected. Vets believe that cryptosporidium exposure rates are high in dogs. 

Your vet may verify cryptosporidium infection by performing an animal inoculation. To perform this test, your vet will need to isolate oocysts, the infectious form of the cryptosporidium protozoa, in your dog's fecal matter and inject them into mice. The results of this test take a week to develop, but they can definitively tell your vet whether or not your dog is suffering from cryptosporidium infection. However, laboratory examination of a fecal example is also a largely reliable way to verify cryptosporidium infection.

Treating Cryptosporidiosis in Dogs

In most cases, dogs recover from cryptosporidiosis on their own. If treatment is required, antibiotics may be prescribed. A high fiber diet can help relieve the symptoms of diarrhea associated with this infection. Support therapy, such as fluid replacement therapy, can help dogs suffering from dehydration as a result of cryptosporidium infection.

Preventing the Spread of Cryptosporidiosis

If your dog develops a cryptosporidium infection, make sure you protect yourself, your family and your other pets from infection by disinfecting any contaminated areas in your dog's environment with a 1:10 bleach and water solution. Wash bedding in hot water and soap.

Keep your dog isolated from other pets, children and individuals with compromised immune systems. Cryptosporidiosis is very contagious and can spread to cats, rodents and calves as well as people. People suffering from HIV or AIDS are at the highest risk for cryptosporidiosis. Cryptosporidium can cause chronic diarrhea and severe dehydration in people with HIV or AIDS, and can easily develop into a life threatening secondary infection in those with compromised immune systems.