The final hosts for the capillaria plica parasitic worm are the dogs and the cats that many humans call pets. The domesticated animals often get the parasite from earthworm scat found in the dirt that they play around in outside. This is especially true for stray or feral cats that spend more time in the dirt than their domesticated counterparts. Once the eggs hatch, the larva grow.
When the larvae have matured, they can then get into the dogs and the cats. They do this by burrowing into the skin, which can result in itchy rashes and lesions that the animals then scratch at. Once inside the animal, the worm feeds on its host, but in many mild cases, don’t do enough damage to make themselves known.
