What is Cuterebra in Dogs?

The shaggy dog looked just like the pooch from the movie of the same name except in two respects. He was obviously homeless and had been eating the feral cat food at our door for weeks. He was also the filthiest dog I had ever seen. Animal rescuers faced with this situation generally use whatever means possible to get such an animal directly to a vet without taking it inside their homes first. As I latched onto a hunk of fur, I noted a lump on the neck and assumed it was probably a hair mat or - shudder - a nest of fleas. Little did I suspect that the dog had a cutrerebra infestation.

What is a Cuterebra Infestation?

According to WebMD, cutrerebra refers to a fly larva about an inch long and half as wide. These larvae form lumps beneath a dog's skin that look like cysts. Each lump or bump has an opening in the center so that the insect inside can breathe. It's possible to actually see the insect's head in the hole. When the vet showed me this, I lost my appetite for lunch.

These lumps typically occur on a dog's neck, at various spots on the abdomen or under the chin. PetPlace.com indicates that the larvae can also be found in squirrels, rabbits, cats and rodents.

The most typical way a dog acquires cuterebra is by visiting the den of an infected animal. For abandoned or wild dogs like the one who dined with us, this can be a daily activity in all but the coldest climates.

According to MyPetsDoctor.com, the cuterebra is a fly that resembles a bee. This insect lays her eggs on stones or on vegetation, particularly on animal paths and in burrows. Once the eggs get onto the dog's coat, body heat causes them to start hatching. The larvae are able to take over the dog as a host when they enter the mouth or nose when the animal is grooming itself.

Once the dog ingests the larvae, they will migrate to the skin and form a hole in order to breathe. Although I didn't notice it, typically, pus drains to the outside of the skin. After living on the dog for around four weeks, the larvae come out the hole, drop to the ground and go into a cocoon stage.

Diagnosis and Treatment

A veterinarian can easily diagnose a cuterebra infestation just by looking at an infected dog.

Treatment for this condition doesn't require the use of high-tech drugs but a strong stomach, a good set of clippers and steady hands. In the case of all but the most cooperative of patients, the vet will need to put the dog under general anesthesia. Whenever possible, the dog should have an empty stomach when anesthetized. If the dog is a domestic pet and doesn't mind being handled, it might be possible to use only light sedation.

Once the dog has been sedated or anesthetized, veterinary staff clip or shave hair from around the area of the lump. In a case of a dog with multiple sites, it might be necessary to shave off most of the animal's hair.

After disinfecting the area of infestation, the vet uses forceps to make the opening big enough to pull out the larva without causing it to burst. Should foreign matter from a burst larva enter the wound, the dog could die from anaphylactic shock.

Once all larvae have been removed, the staff irrigates the wound and utilizes the standard abscess treatment. Owners or rescuers will need to give the dog systemic antibiotics after surgery. In some cases, vets also prescribe topical ointments to help prevent infection after surgery for cuterebra infestation in dogs.

Sources:

http://pets.webmd.com/cats/cats-lumps-bumps-skin

http://www.petplace.com/dogs/cuterebra-infestation-in-dogs/page1.aspx

http://www.mypetsdoctor.com/treatment-of-cuterebra-larva-infestation-in-cats-and-dogs

Personal experience as an animal rescuer