Aelurostrongylus abstrusus larvae in the colon of two cats.

A 12-year-old male domestic shorthair cat with a history of depression, aggression, and fever was presented for necropsy, and formalin-fixed tissues from a second male domestic shorthair cat of unknown age were submitted for histopathologic examination to the Athens Veterinary Diagnostic Laboratory. Both cats had granulomatous pneumonia associated with large numbers of parasite eggs and larvae, consistent with Aelurostrongylus abstrusus. Both cats also had larvae within glands in the colon that were identified morphologically as A. abstrusus first-stage larvae.