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Cuterebra Larva

Cuterebra is a parasite of rabbits and of cats. There is a fly that doesn’t have any mouth parts that usually lives in the ground and lays eggs on the outside of the shoulder or the face of rabbits or cats. The egg hatches and the larvae burrows into the skin, creating a lump on the face. It can live 4-5 months before it comes out. If your animal is infested with Cuterebra, there will be small breathe hole in the lump. If it is Cuterebra you don't want to rupture the worm. If you do, the foreign protein entering the cat’s system could kill it.

Life Cycle:

The adult female lays her eggs near the entrance of a rodent burrow. The eggs hatch and the first instar larvae wait for a host. When a host passes by they attach to the hair and move to the skin. Once on the skin they move to natural body openings such as the nares. Inside the nose they penetrate the mucosa and migrate to a subcutaneous position. The larva then cuts a hole in the skin in order to breath. The larva grows and molts until it has become a third instar and about 25 mm long, this takes 3 to 4 weeks. The larva will then emerge through its breathing hole and drop to the ground where it will pupate under the soil. The fly may overwinter as a pupa. In the spring the fly will emerge from the pupal case. Adult flies do not feed and will live for about 2 weeks.

Clinical Signs:
Depends on where the larva is located:

In the skin the larva causes few problems.
In the trachea the larva may block the air supply
In the brain will cause neurological symptoms consistent with the area of the brain in which it is located.

Surgical removal of the intact larva.