The Classic Comprehensive Handbook of Cat Care: FLUKES (TREMATODES)
Like protozoans, trematode parasites are uncommon causes of disease in cats. One fluke, Paragonimus, can cause cysts in the lungs of both cats and dogs, leading to a chronic cough and pneumonia. Infection can be prevented by keeping your pet from eating raw crayfish or from drinking water contaminated with infective stages of the fluke.
Infection can be diagnosed by finding the microscopic fluke eggs in the stool or lung secretions. Treatment is with praziquantel or fenbendazole. There are several other kinds of these flatworms which parasitize different parts of the body including the lungs, liver, and small intestine. Signs of infection vary greatly and diagnosis must be made by a veterinarian. You can prevent infection of your cat by restricting hunting since infection is usually acquired by ingesting prey, including raw fish, certain crayfish or crabs, frogs, reptiles, or snails, and rats.