Because Pythium Insidiosum lesions progress rapidly a quick diagnosis is essential for animal survival. Most veterinary practitioners are not aware of the disease, nor of the blood test, so recognition is important. The diagnosis of oomycete infections can be difficult due to clinical and histological similarity to fungal infections.
Special expertise is required for diagnosis by biopsies, so diagnosis is difficult because the organism requires warm temperatures to thrive. On biopsy you need a trained eye and special stain to identify the hyphal structures of the organism, and it can take considerable time for these special laboratory procedures.
Abdominal radiographs in dogs with gastrointestinal pythiosis may show an intestinal blockage, intestinal wall thickening or defect, and/or abdominal mass. An ultrasound image of the dog’s abdomen will tend to show thickening of the wall of the stomach or intestines. Enlarged lymph nodes may be evident due to the infection.
A complete blood count may be normal or have a slightly higher white blood cell count due to the infection, but will not show a Pythium Insidiosum infection. Only two labs specialize in a serological test employing ELISA (Enzyme-Linked Immunosorbent Assay) technology to detect antibodies to Pythium Insidiosum, Louisiana State University and PavLab. PavLab’s test shows the level of antibodies in a dog’s bloodstream in order to determine the level of exposure to the pathogen.