Blastocystis hominis is a microscopic intestinal parasite that can be detected in stool. In dogs, exposure can occur through contaminated water, food, soil, faeces, or environments where faecal contamination is present. Low levels may occur without obvious digestive signs. Higher levels may suggest that Blastocystis is present in greater amounts in the intestinal tract, which may be more relevant when the gut environment is irritated or the gut microbiome pattern is less balanced. Higher levels may be seen together with altered stool quality, soft stools, diarrhoea, gas, mucus in stool, reduced appetite, or digestive discomfort. A positive finding may be useful to review with a veterinarian, especially if ongoing digestive signs are present or if there are concerns about hygiene or environmental exposure.
