Parasites are organisms that survive by feeding off of other creatures. Among cats, parasites generally feed on animal's blood. Detecting internal parasites can be difficult, but a close inspection of skin and fur is usually all that is needed to uncover traces of external parasites such as ear mites and fleas. There are many types of worms that are internal parasites to cats. If you see small, rice like debris around your cat's anus or in her bedding, take her to your veterinarian. He will need to run simple tests to identify what type of worm is present so that he can prescribe proper medication to eliminate parasite.
Coccidia are microscopic parasites. They live in cells within lining of intestines. The most common symptom is diarrhea. Left untreated, animal becomes extremely weak and dehydrated. Fortunately coccidiosis is treatable. Drugs such as sulfadimethoxine (Albon) and trimethoprim-sulfadiazine (Tribrissen) are effective in treatment and prevention of coccidia. However, these drugs do not kill parasites, but rather inhibit reproduction - elimination of coccidia from intestine is slow.
Ear mites take up residence in a cat's ear canals. As they feed, they cause intense itching. A cat suffering from an infestation of ear mites scratches behind her ears often and is seen violently shaking her head on a regular basis. If you look inside her ears, you will see dark flecks that resemble coffee grounds - these are mites' droppings. If you suspect ear mites, contact your veterinarian.
There are several effective treatments for ear mites, such as Fipronil (Frontline) and Selamectin (Revolution). Ear mites are easily treated with eardrops, but are very contagious to other cats. If you have a multi-cat household, isolate infected cat as soon as possible. Ear mites are not transmitted from cats to humans.