Improved Antigen Detection of Male-Only Dirofilaria immitis Infections in Canine Serum after Heat Treatment for Immune Complex Dissociation

Since the mid-1990s, male-only heartworm infections have been considered undetectable using antigen tests based on experimental studies. Results from those studies are in contrast to reports decade prior showing variable male detection naturally infected animals and chemical and/or heat immune complex dissociating steps. Several recent utilizing treatment for dissociation (Heat ICD) demonstrated increased sensitivity necropsy verified a higher-than-expected frequency of this type infection. This study utilized archived canine serum with evaluate DiroCHEK® (Zoetis LLC, Parsippany, NJ, USA), Witness® SNAP® Heartworm RT (IDEXX Laboratories, Inc., Westbrook, ME, USA) tests. showed significant increases following (+42.1%, p < 0.0001) (+26.3%, = 0.0020), but not (+10.5%, 0.1250). Prior treatment, false negative results were obtained 76.3–83.0% mature infections. Infections only immature worms never detected any test used. Heat allows improved infections, which may occur more frequently than previously recognized, like all pose risk chronic cumulative pathology as well thromboembolic disease regardless infection intensity.