We don't see some of the parasites listed below in all geographic areas, or in some cases, frequently in cats as a species. Parasites have adapted to take advantage of their cat hosts in some unusual ways as you will read below—interesting reading!
These flies (Cuterebra) are normally parasites of rabbits and rodents. The fly eggs are deposited on blades of grass, and a cat out hunting can pick up the eggs as she walks past. The maggots then find a body orifice to enter, and migrate throughout the body tissues, eventually producing an encysted larva or bot (warble) under the skin. Migrating larvae can also produce problems in the body systems as they migrate. Eye problems, or respiratory or nervous signs may result. Usually found in late summer and early fall in the Northern US, it occurs throughout most of the year in the South. Treatment is carried out with ivermectin, a broad spectrum anti-parasite medication, and surgical removal of warbles under the skin will be done.
Platynosomum concinnum infection occurs in cats living in tropical areas such as Hawaii and Florida . Transmission is via eating an intermediate host (frogs and lizards). Many cats have no symptoms, but signs can range from loss of appetite and vomiting, to jaundice and diarrhea. Diagnosis is made by your veterinarian who must rule out other causes of liver disease. Definitive diagnosis is made by performing liver biopsy, with microscopic analysis of cell changes. Treatment involves fluids, proper nutrition, wormer,+/- antibiotics, and anti-inflammatory medication. Prevention is possible by treating susceptible cats with a worming product every three months or keeping them indoors.
Intermediate hosts are snails and crayfish. Paragonimus kellicotti is the name of the parasite. Generally, signs reflect damage to the lung and include pneumonia. Most commonly found along the eastern seaboard of the US , the Great Lakes region, and in Louisiana . Diagnosis is made by your veterinarian using lung X-rays and / or a fecal exam. Treatment includes wormers and supportive care for the cough. Follow up X-rays and fecal exams should be performed to confirm treatment effectiveness.
Aleurostrongylus abstrusus is the name of the worm that colonizes the lung tissues. The larvae are produced and then swallowed and passed in the stool. The source of the infection is likely voles and mice that carry the larvae, which develop in snails. Sometimes appetite loss and cough are seen. In severe cases, breathing difficulty may develop.
Lice infestations with Felicola subrostratus are uncommon. Dandruff and itchy skin are commonly noted signs.
Generally a problem only in California , the Thelazia parasites irritate the eye and sometimes, surgical removal is performed.
One might rarely note them in vomit or stool. The Physaloptera. worm may cause poor haircoat, poor appetite and sometimes vomiting. This worm irritates the stomach lining, leading to gastritis. Cats pick them up by eating insects which are carrying the larvae. Diagnosis is by endocscopic examination of the stomach, and visualization and retrieval of worms. The feces may also contain eggs. The parasite is cleared with wormer medication and gastritis is treated symptomatically.
Capillaria feliscati is a urinary tract parasite that usually invades the lining of the bladder, but may also be in the kidney or ureters less commonly. Cats may show no signs, or appear to have lower urinary tract disease. Eggs may pass in the urine. Though rare in the USA , in other parts of the world ( e.g., Australia ) it is quite prevalent.