What Causes a Wolf Worm in Baby Kittens?

Unusual skin lumps with a small hole usually indicate a wolf worm.
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Parasites are a disgusting and unfortunately common problem cats must face, with the various creepy crawlies invading your kitty's body to use as they please. One such freeloader is the wolf worm, the larvae of the Cuterebra or North American bot fly. Your kitten is essentially its unintentional nursery.

Preferred Hosts

As disgusting as it is, your cat is a victim of being at the wrong place at the wrong time when he picks up the wolf worm. The Cuterebra fly's preferred hosts are rodents and rabbits, and the insect lays her eggs near the small animal's burrow. Once the egg senses a temperature increase, such as from a warm-bodied host nearby, the larvae hatches and crawls on the furry body of its new mobile home. The worm then works its way to the host's face, where it crawls up the nose or waits to be eaten during grooming. Once inside the host animal, the larvae travels through the host animal's body, possibly causing damage in its voyage. It usually comes to rest under the skin, where it makes a hole for itself to breathe through and continue its development.

The Accidental Host

Since cats are born hunters, most won't pass up the opportunity to investigate the burrow of a mouse or rabbit. Curiosity is a well-known cat trait, and even little kittens like to check out holes and possible small animal hideouts. This leaves the felines vulnerable to infestation of the opportunistic parasite, and even small kittens can become infected if the hatched larvae falls off the mama cat's fur as she returns to her litter. The wolf worm isn't picky and invades the closest host it can find, which may include very young kittens.

Possible Infection Sites

Parasites in general are pretty gross, and the thought of a maggot roaming around inside your kitten's body likely passes an involuntary shudder through you. The wolf worm migrates through your kitten's various tissues and organs, and can cause potentially fatal side effects such as neurological damage by passing through the brain. In most cases, once the worm is finished traveling through the kitten's body, it settles down on the head or neck and is identified by the discovery of its breathing hole.


If you have a particularly strong stomach, you may think that you can simply remove the larvae yourself once you find it. While it's technically possible, this is one parasite treatment you should leave to the professionals. The worm needs removed completely to prevent the possibility of a serious secondary infection, and improper removal may cause it to burst. Take your infected kitten to your veterinarian to have the worm removed and the remaining hole properly cleaned.

Always check with your veterinarian before changing your pet’s diet, medication, or physical activity routines. This information is not a substitute for a vet’s opinion.

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