A couple of times a year you enter the treatment room and sense a different level of excitement; as you step closer to see why everyone is huddled around a patient "oohing and aahing' you realize it is the seasonal reoccurance of the cuterebra....very 'cute' to some but quite ugly to others. In most instances there is at least one staff member present who has never seen this condition. Interestingly enough, in this case the owner of our patient had seen this parasite before...she has rescued/given homes to many a stray over the years.

Mr. Dameanor

Mr. Dameanor was presented to us for evaluation of significant facial swelling. He is yet another stray taken in to this loving feline family. The physical examination revealed an area of diffuse firm swelling, there was some fluid drainage and a very circumscribed central hole. The telling factor was the sense that there was movement to a dark structure deep in the opening. The clinical findings, along with the history supported a diagnosis of a cuterebra larva.

Cuterebra larva result from cuterebra flies laying their eggs near rabbit nests and rodent burrows. The hatched larvae enter the host through body openings; the mouth and nares (nostrils) while grooming or through open wounds. After the penetration the larvae migrate to various subcutaneous locations on the body where they develop and communicate with the air through the open breathing hole. Normal hosts to the cuterebra are rabbits, squirrels,chipmunks and mice. The problem is uncommon in dogs and cats, but when encountered it is usually in late Spring or Fall. The clinical findings are typically of a subcutaneous swelling with the surrounded area matted from fluid drainage or increased grooming. The central breathing hole, with a dark moving structure deep within it, is the classic physical finding.

cuterebra larva

Treatment is fairly straight forward, but care must be taken to remove the larva without rupturing it as that can lead to a chronic foreign body reaction and secondary infection. After topical/local anesthesia is applied the breathing hole is enlarged and the cuterebra is carefully extracted with forceps. Routine wound care follows with antiseptic flushing and systemic antibiotics for secondary bacterial infections. The wounds tend to heal uneventfully but slowly.

In this case Mr. Demeanor had certainly "read the book", as had his owner. She already had the diagnosis in hand when she arrived with her new stray. (Being an avid reader of mysteries she had an edge up on figuring out this unusual situation). We discussed a treatment for Mr. Demeanor and had the problem solved quickly and uneventfully.