Cuterebra fly lays its sticky eggs on the long blades of grass around burrows in the ground. Small animals such as rabbits or cats get the eggs caught on their fur around their head and face. The eggs hatch and the larva crawls down into the fur and burrows into the skin creating a cyst. The cyst grows larger as the larva increases almost an inch in length. The parasite breathes through an opening in the skin. Eventually the skin ruptures and the larva drops out to complete its cycle. By themselves, the larva and the cyst don't cause much of a problem to the cat, except for a mild localized infection. However, most cat owners understandably object when they see a huge maggot moving around the skin and request its removal. This should be done only by a veterinarian because rupture of the maggot can cause an anaphylactic reaction.
- Caring for your sick cat. Carol Himsel Daly, D.V.M.
- Cat Cuterebra
- Cuterebra life cycle (cdc.gov)