Feline Cuterebrosis (Warbles)

Kitten with a Warble

Kitten with a warble.

Recently, a cat was brought into our clinic with a cyst-like protrusion on its chest. Examination revealed it to be Feline Cuterebrosis, also called “Warbles”, a condition in which fly larvae live in the flesh of cats.

What is Feline Cuterebrosis?

Feline Cuterebrosis is a condition occurring when a cat has become the host of the larval stage of the Cuterebra Fly, commonly known as the Botfly.

There are twenty-six known species of the Botfly (Cuterebra) in the United States and Canada.

This condition is often called “Warbles” because the larvae create a burrow with a breathing hole just under the skin causing a lump on the surface of the skin. These lumps are called “warbles”, hence the name.

Feline Cuterebrosis (Warbles) - Botfly or Cuterebra Fly

The Cuterebra Fly, commonly known as Botfly.

Warbles are usually found under the skin in areas around the legs and neck. Cuterebrosis is most commonly found in rodents and rabbits, but have also been reported on cats, dogs, hogs, mink, foxes, deer, cattle, and humans.

What Causes Feline Cuterebrosis ?

Cuterebrosis is a condition most commonly found in wild rodents and rabbits. This condition is caused by the larvae of the Cuterebra fly, which also known as the botfly.

Feline Cuterebrosis (Warbles) Botfly Larva

This is the larva that Dr. Smith removed from the cat’s neck.

The female botfly, genus Cuterebura, lays eggs along the runways and burrow entrances of rabbits and small rodents. The eggs hatch and turn into larvae which enter the unsuspecting host through a natural body opening (usually the nose or mouth) or a small abrasion on the skin.

The larvae will often remain in an animal’s the nose or mouth for several days before burrowing under the skin where they develop into “warbles”. (“Warbles” is the name given to the small lumps produced by growing larvae.) The larvae live and grow just under the skin inside the “warbles”, where they breathe and excrete.

Cats most likely contract Cuterebrosis  by coming in contact with the newly hatched and unsettled larvae from rodents caught hunting, or from  activity around rodent burrows and runways.

Most cats are asymptomatic in the early stages of Feline Cuterebrosis, but sometimes migrating larva can sometimes cause eye problems, nervous system symptoms, and respiratory issues as they move through these systems.

Feline Cuterebrosis (Warbles)

This is the hole left in the cat’s neck after Dr. Smith removed the larva.

How is Feline Cuterebrosis (Warbles) Treated?

Feline Cuterebrosis is treated by carefully removing the larvae and thorough cleaning of the area involved.

Often the cat will be given antibiotics or an antibiotic injection to treat any possible or already occurring secondary infection.

This particular procedure was done under anesthesia and the cat was given an antibiotic injection to treat and prevent secondary infection.



Becki Baumgartner, Practice Manager (87 Posts)

Becki Baumgartner runs the Natchez Trace Veterinary Services Nashville clinic. She is training to become a Certified Master Herbalist, has a BS in Natural Health, and holds membership in both the Nashville Medical Reserve Corps and American Holistic Medical Association. Becki also teaches Reiki and Herbology continuing education classes in Nashville and surrounding areas. Natchez Trace Veterinary Services offers a full range of veterinary services from cutting-edge Western medical treatments combined with alternative treatments, herbal formulas, and holistic options that many pet owners cannot find anywhere else. Becki utilizes her natural health and herbal experience, skills, and knowledge to help pet owners understand all of the holistic, alternative, herbal, and standard options options available and achieve and maintain optimum health for their pets. Chat with Becki on Google+ | LinkedIn | Facebook

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  1. sleepyjean1979 says:

    I have encountered this larva in a 6wk old kitten in the sinus cavity with the breathing hole near the inner corner of the eye. I squeezed not knowing this worm like creature would pop out with some force and speed. This kitten could not walk correctly and died within days of the removal. That was in year 2012. Does anyone know how long these warbles have been in the Tennessee area?

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