Symptoms of parasites in cats are wide-ranging, depending on the type of parasites involved. External parasites cause the cat to itch, which leads to scratching and sometimes chewing on the areas of skin that are affected. Hair loss and dry skin can also result from external parasites. Internal parasites can cause appetite loss, diarrhea and vomiting. Anemia can result from both internal and external parasites.
External cat parasites include fleas and ticks. When a cat has fleas, dark specks can usually be spotted in the cat's fur and around the area where it sleeps. An affected cat will often scratch and chew around the base of its tail, where fleas congregate. Ticks obtain nutrition from cats' blood and transmit various diseases. Rocky Mountain Spotted Fever causes intestinal upset, and Lyme Disease can result in arthritis.
Parasites in cats can cause allergies. When infested with fleas, some cats suffer allergic reactions to the fleas' saliva. These reactions, called flea allergy dermatitis, result in hair loss, dry skin and raised lesions that are red in color. Sometimes the cat might pull out its own fur. Symptoms of flea allergy dermatitis grow worse in summer and fall, when fleas are more prevalent.
Ear mites, one of the most common feline parasites, cause itching and will often make a cat shake its head back and forth. Infection can result from ear mite infestation, since the mites get their food from the fluid in a cat's ear. If ear mites are left untreated, the complications of bacterial infection could make a cat go deaf.
Tapeworms, an internal parasite in cats, are passed to felines when they ingest fleas that have eaten tapeworm larvae. Symptoms of tapeworm infection include itching around the cat's anus and the presence of tapeworm segments around the anus or in the cat's feces. If a cat has a great many tapeworms, it can suffer weight loss and malnutrition.
Hookworms and roundworms are two internal parasites in cats that can cause damage to a cat's health if left untreated. Hookworms usually feed on the small intestinal lining, but sometimes they feed on blood. Symptoms include blood in a cat's feces, weight loss and anemia. Roundworms, a common intestinal parasite in cats, can cause diarrhea and vomiting and are particularly dangerous for kittens and sickly mature cats.
Outdoor cats are prone to parasites such as lungworms and flukes. The main symptom of lungworm infection is coughing. Flukes can cause loss of appetite and swelling of the cat's abdomen.
Getting rid of parasites in cats is best accomplished by a visit to a veterinarian. Many effective medications are available that will eradicate parasites. The best methods of preventing parasites are ensuring that the cat receives regular veterinary care and either keeping it indoors or not allowing it to roam outdoors unsupervised.