Indirect fluorescent antibody (IFA) assays to determine IgM and IgG titres to B. canis are available through diagnostic laboratories.
Polymerase Chain Reaction (PCR) of whole blood is generally available but results should be interpreted with caution because the techniques used in different diagnostic laboratories vary. Amplification of related organisms by nonspecific primers can result in false-positive reactions. Conversely, false-negative may also occur if extraction procedures fail to remove PCR inhibitors present in a blood sample. They may also occur if the level of circulating parasitaemia falls below the level of assay detection, due to normal decrease in circulating organisms or temporary suppression of the infection following treatment. To maximize the utility of molecular diagnostics, blood samples should be collected early in the course of clinical disease and before the initiation of chemotherapy, and they should be submitted to experienced diagnostic laboratories with stringent quality control measures in place.