STRESSED STEEDS

Article Tools

Image Gallery

Print

E-mail

Comments

RSS

Our six-year-old cat, Melba, hunts rabbits, mice, and moles all the time. She recently had a swelling on her neck which turned out to be a bizarre grub of some type. Can you explain this?

—Andrew Meyers
South Bend, IN

Dear Andrew,

Country cats and kittens, especially those that are good hunters, frequently come down with abscesses on their head, face, neck, and legs. Often these are simple bacterial accumulations, either from fight wounds they obtain in their entanglements, or from bacteria or yeast caught on sticks and branches they encounter on their way into the rabbit hole. Yet there are some lumps and bumps that contain a grub known as a Cuterebra, or botfly larva.

Female Cuterebra flies lay their eggs along rabbit runs and near rodent burrows. As the cat or kitten (on its way down a burrow) brushes past, the larvae hatch instantaneously and crawl immediately into the host's fur. Once thought to burrow directly into the host's skin, these larvae are now known to enter the body through natural openings — nose, eyes, and ears being the most prominent. The larvae begin maturing and often migrate to sites under the skin on the head and neck, although some have been found on the lower body region and even entering the brain or spinal cord. These latter aberrant migrations, as they are known, often result in blindness, incoordination, and stupor, and commonly have fatal results.

If you notice a lump or bump on your cat and suspect it contains a larva, there should be a hole through which the larva breathes at the skin's surface. Often these grubs are very hardy and the hole leads to a fibrous tract penetrating under the skin for great distances. Bacterial abscesses that are open to the air like this often heal on their own. Cuterebra abscesses will not. Try to extrude the organisms by injecting hydrogen peroxide in the opening. If the bot comes to the surface it may be grasped with forceps and extracted the rest of the way. Do not break the Cuterebra or force your way into the animal's skin to retrieve it. These manipulations often result in crushing of the larva and inflammation of the opening in the skin. Once the larva is removed, these wounds often heal slowly or only partially because of the secondary bacteria that invade with the bot, or because of the breakdown of the larva and release of its toxic substances into the tissues around the abscess. Cuterebra infections are common in warm, damp environments and late summer seasons.

With the advent of blackfly season, our collie, Lucy, has obtained a large swelling in her ear flap. Is this due to the fly bites, and is there anything we can do to prevent them from occurring?

RSS | Comments | E-mail | Print