Expert: Jessica - 5/4/2011

Question
My 2 year old male tabby has a lump the size and shape of a maggot near his backbone.  It can be pushed from side to side when you touch it so does not seem to be attached to the insides ( not a cyst I think then. I have only just noticed the lump recently about the same time I noticed a maggot I found in his dinner( tescos tin cat food!)I am not sure whether there was any previous ones he might have eaten but he seemed to be ok healthwise.Is the lump anything to worry about?

Answer
Hi Julie,

Lumps should be investigated by a vet. Some are benign, but some are worrisome. Those that are movable are more often less harmful than those that tend not to move easily. It may be a lipoma (a "fatty tumor" made up of a deposit of fat) or a sebaceous cyst (a collection of a substance called sebum, an oil secreted by glands under the skin). Both of these are nothing to worry about. But any lump could be cancerous.

Cats can also become hosts to parasites such as the larvae of bot flies. These truly are maggots which burrow under the skin. They will continue to grow there for 3-4 weeks, causing a lump called a warble. If all goes well, the super-sized larva will back out of the breathing hole it leaves in the skin and drop to the ground, where it will move on to its next life cycle. However, complications can be common with these parasites and include infection of the wound and failure of the parasite the remove itself. If the larva dies, the cat can have a deadly reaction to toxins that leak from the decaying maggot. It's important not to try to remove the larva yourself. If you burst the larva or kill it, you risk causing that deadly reaction. Only a vet should try to remove it.

As far as other types of worms or maggots that can infect the skin, rarely, a cat can become infected with regular maggots that normally are found in garbage or fecal matter, but these typically occur in wounds that are already present, and there will be many maggots. This is an emergency situation. The wound needs to be treated and the maggots need to be removed. The cat won't have become infected by eating maggots, but by the wound coming in contact with eggs or the maggots themselves.

There are no common worms that will enter the skin aside from hookworms, but these are too tiny to see.

I hope all turns out well!

Jessica