There are numerous types of internal and external parasites that infect cats. Internal parasites enter the body of the feline and select one of the feline’s internal organs. An internal parasite can live in the heart, lungs, liver, intestine, or stomach, whereas an external parasite retires to the skin and hair of a feline. A parasitic infection can cause the feline to lose weight, develop skin conditions, lose hair, become resistant to physical activity, cough, lose blood and even die suddenly due to the parasites taking over the body. Some cats do not show signs of a parasitic infection, which is why a veterinary evaluation is required. 

A parasitic infection in cats is characterized by one or more parasites using the feline as a host. Parasites are organisms that need a host or other living organism to carry out their life cycle. A parasite can live on or inside a feline’s body, causing numerous health problems that can be life-threatening. Parasites live in the environment and use intermediate hosts as transportation to their permanent host. A cat can infect herself with a parasite by drinking contaminated water, eating contaminated food, coming in contact with an infected animal, being bitten by a mosquito, being bitten by a tick, or from cleaning her paws after being outside. Other parasites can latch onto the cat’s fur, crawl into the ears and even burrow into the skin or hair follicle. 

Symptoms of a parasitic infection in a cat could be numerous or non-existent, depending on the severity of the infestation and the type of parasite infecting the cat. Some parasites, such as tapeworms, fleas or ticks, are large enough to spot on the feline or within the fecal matter. Other parasitic infections can be spotted through a feline’s symptoms including: 

The exact cause of a parasitic infection in cats depends on the type of parasite the feline is infected with. External and internal parasites can infect any feline, however, cats with poor immunity, that live outdoors, are very old or very young, or live in poor conditions are more prone to an infestation. 

External parasites usually infect a feline during the warmer parts of the year, when the eggs hatch in the environment. Fleas, ticks, mites, and lice latch onto the cat when she goes walks through tall grass, climbs a tree, or comes into contact with another infected feline. 

Internal parasites can be transmitted to a feline through a flea bite (tapeworms), mosquito bite (heartworms), ingestion of contaminated meat (tapeworm/roundworm), drinking contaminated water, coming into contact with contaminated feces or cleaning of the paws after being outdoors (whipworms).

The diagnosis of a parasitic infection can be done through an examination of the blood, feces or urine of a feline. The exact diagnostic test depends on the type of parasite the feline is infected with, but your veterinarian may choose to perform:

An external parasitic infection in cats may be treated orally or topically, depending on the severity of the infestation. Ask your veterinarian about the appropriate flea, tick, mite, or lice treatment product for your cat and her condition. Internal parasites are always treated with oral medication and most are sold commercially. However, heartworms are extremely difficult to treat and your cat may require inpatient hospitalization. Also, if your cat has developed anemia, the veterinarian may advise a blood transfusion in addition to drug therapy. 

The prognosis for a parasitic infection in cats depends on the parasite and the age and overall health of the feline before the infection occurred. Fleas, ticks, mites, lice, tapeworms, roundworm and whipworms are all very treatable, with most patients making a complete recovery. The treatment for heartworms, however, can be difficult for the cat and not all felines make it through the course of treatment. The key to avoidng any parasitic infection is preventing the parasite from taking over your cat’s body. Talk to your veterinarian about steps you can take to prevent a parasitic infection in your cat.