Blastocystis in Dogs

Blastocystis hominis is a microscopic parasite that lives in the intestine of an infected human or in animals such as cats, dogs, pigs, horses and cattle. It can sometimes be found in the stools of both healthy people and those who suffer from diarrhea, stomach pain or gastrointestinal problems.

Blastocystis parasites can be found more in areas with unsanitary conditions, whether it be soil, food or water that has come into contact with contaminated feces. It can be acquired among those who travel to exotic places. One becomes infected by accidentally ingesting the parasite, often by drinking water from contaminated sources or eating uncooked, contaminated food. It often spreads through those who swallow recreational water as well, such as from a public swimming pool, hot tub, lake, pond or river.

In a study conducted in 2013 called "Diversity of Blastocystis subtypes in dogs in different geographical settings," dogs from different areas of the world were tested for blastocystis infection. Nearly a fourth of the dogs in India were infected, while dogs from a Cambodian village and in Queensland were found mostly uninfected. There were four different subtypes of the parasite in the Indian dogs, and it is still under debate whether or not the data indicates that dogs are natural hosts.

A few symptoms can signal a blastocystis infection. These include abdominal pain, diarrhea, constipation, gas, greasy stools, upset stomach and nausea. Patients also disclose suffering from fatigue, rashes and joint pain. Some are more prone to exhibiting severe reactions to the infection, while others report mild to no symptoms. According to the Blastocystis Research Foundation this is thought to have to do partly with the genetic makeup of the individual as well as the perniciousness of some types of microbes.

There are no FDA-approved treatments for blastocystosis infection at this time. It typically clears up eventually. If you see no signs of improvement, then a doctor may recommend certain treatments. So far, though, treatments have had mixed results and have not been reliable. Sometimes, symptoms have actually increased after antibiotic treatment. For this reason patients who aren't exhibiting symptoms may not be wise in seeking treatment.