When we saw Becky and Gatto, we showed them into the exam room. The lump was a little larger than the size of a marble. Though we thought it would be an abcess, upon closer examination, we discovered a small, match head-sized hole at the top of it. Given the time of year and the circumstances, we knew we had a case of "Cuterebra," and we had not seen one of those in a long time.
What is Cuterebra?
The Cuterebra is a bee-like species that lays its eggs near the entrances to outdoor animal dens or burrows. The eggs stick to the fur of any animal that brushes against them and they hatch into larvae, which penetrate the skin, enter the body through a natural opening, or are ingested when the animal is grooming. The larva usually migrates to an area just under the skin on the head or neck of the animal. It then matures under the skin for about 3 weeks, and creates a cyst that can be as large as a marble. The larva creates a tiny hole in the skin surface in order to breathe. This telltale opening is certain evidence that the suspicious growth contains the Cuterebra larva.
Although rabbits are the more common animal parasitized by the Cuterebra, cats can also be affected. Larvae in cats are usually encountered in the later summer months in the north, slightly earlier in the south. Although this condition is not life threatening, it can be irritating to the cat and the open hole can become infected. However, in some cases, larvae may also enter the nerve tissue, such as the spinal cord, rather than become encapsulated below the skin. Though rare, this can cause neurological damage.
We shaved the area around the growth, scrubbed it, enlarged the opening, and removed the gray, spined larva with a forceps. We were careful not to crush it, as this can cause further skin irritation and, in some cases, an allergic reaction. We flushed out the hole with antiseptic and prescribed a topical antibiotic ointment for Becky to apply.
How could this have been prevented?
We always recommend that a cat be kept indoors at all times except if he can be in a safe and parasitic-free area, such as in a Kittywalk enclosure. Outside cats live much shorter lives, mostly because they are exposed to wildlife and diseases that they would not encounter inside the house. For more information on Cuterebriasis, click here.