Worms, Mites, Ticks and Other Bugs That Live on Cats

Common parasites in cats
Cats can get a number of different types of parasites.

Illustration: Hugo Lin. © The Spruce, 2018 

Cats are susceptible to many different types of parasites but there are two main classifications of them. Cats will either get internal or external parasites. Internal parasites are inside the body while external parasites live on the outside of the body in the skin or ears of a cat but no parasite is a good parasite. It's important for cat owners to do what they can to prevent parasites from infecting their pets.

  • 01 of 06

    Mites

    Cheyletiella Mites
    Cheyletiella mites are often referred to as walking dandruff. Agency-Animal-Picture / Getty Images

    Mites are a tiny type of arachnid but they don't look like a spider. These external parasites are typically unable to be seen without the use of a microscope and can infect different parts of a cat. Preventative medications can be used to help keep a cat from getting mites but they usually need to be administered monthly. The types of mites seen on cats include:

    • Demodex - Also referred to as demodectic mites and demodectic mange, demodex is a mite that lives on or in the skin of cats and an infection of these mites is called demodecosis. Two different species of demodex can be found on cats: Demodex cati and Demodex gatoi. Normally there are very small amounts of these mites on a healthy cat but if a cat is immunosuppressed they may overpopulate and cause itching, hairloss, skin inflammation, and crusting. Diagnosis of these mites typically requires a scraping of the skin and analysis under a microscope. Treatment involves topical and/or injectable medications to kill the mites and treat the symptoms of the infection.
    • Walking Dandruff - Known technically as Cheyletiella mites, an infection of these mites is called cheyletiellosis. They get their name from the way they look and the scaling that they cause to the skin. They may be able to be seen moving around on a cat without a microscope or otoscope but are very tiny. They cause itching as well as the skin scaling but are easily treated with topical medications.
    • Scabies - Also called notoedric mange, scabies mites burrow into the skin of cats. The specific mite that causes scabies in cats is Notoedres cati and it is very closely related to the sarcoptic mange that dogs get. It is very rare but causes itching, crusting, and scaling of the skin. It is usually treated with topical medications.
    • Ear Mites - Very commonly seen in cat ears, Otodectes cynotis, are mites that cause the typical itching that other mites also cause. They are usually treated with topical medications and are very contagious to other cats.
  • 02 of 06

    Fleas

    Up close image of a flea
    Fleas are tiny external parasites.

     Getty Images/Coopder1

    Fleas are not uncommon external parasites on dogs and cats but since cats are such fastidious groomers they may not be as obvious to a pet owner as they would be on other animals. Fleas can infest an environment quite easily. They take blood meals from cats and reproduce rapidly making it difficult to eradicate them from some homes. Sprays and powders along with topical medications are used to treat a flea infestation but preventative medications can be easily administered to prevent them from causing a problem in the first place.

    The cat flea, Ctenocephalides felis, can also transmit serious diseases and parasites in addition to the itching and hairloss that pet owners see. Because of this, preventing fleas is more than just preventing a nuisance. Less commonly, cats can also be infested with the dog flea, Ctenocephalides canis, which can also transmit parasites to a cat.

  • 03 of 06

    Intestinal Parasites

    Giardia lamblia

    Jerad M Gardner, MD / Wikimedia Commons

    Intestinal parasites are internal parasites that can be worms, eggs, or protozoan. These tiny parasites live inside the stomach and intestinal tract of cats and only the worms are visible to the naked eye. In order to detect them, stool samples are routinely tested by a veterinarian and various medications will be utilized to treat intestinal parasite infections.

    • Giardia - This microscopic protozoan is also a problem for humans and attaches itself to the wall of the intestines of cats. It causes diarrhea and is passed to animals and people in contaminated soil and water.
    • Coccidia - Another microscopic parasite, this parasite also causes diarrhea in cats. There are several different types of intestinal coccidium that can infect cats including Isospora felis, Isospora rivolta, Sarcocystis, and Toxoplasma gondii (which humans can also contract).
    • Whipworms - This intestinal parasite has a larval or worm stage which is often seen by cat owners but the eggs can be noticed microscopically. Trichuris vulpis, the technical name for whipworms, causes diarrhea.
    • Hookworms - Another intestinal parasite that has both a worm stage and microscopic eggs, hookworms also cause diarrhea and other gastrointestinal symptoms in cats. The most common types of hookworms seen in cats are Ancylostoma tubaeforme and Ancylostoma braziliense.
    • Roundworms - A very common type of intestinal parasite, roundworms are usually described as spaghetti-looking worms in the stool of cats. They also have an egg stage that is microscopic. These worms often cause a bloated or round belly appearance in cats along with loose stools and occasionally even vomiting.
    • Tapeworms - If a cat consumes a flea they may get tapeworms. The worms of this intestinal parasite look like pieces of rice in the stool but there are microscopic eggs as well. This worm is known to cause weightloss.
  • 04 of 06

    Ticks

    Lxodes Ricinus
    Agency-Animal-Picture / Getty Images

    Larger than fleas and mites, ticks are external parasites that latch onto a cat in order to feed off of its blood. Ticks can carry a variety of diseases but preventative medications can keep them off of a cat. There are several different kinds of ticks that cats can get depending on what part of the country the cat is in. Some common kinds of ticks include:

    • Lone Star Tick - This type of tick is only occasionally found on cats. The technical name is Amblyomma americanum and this tick can spread a potentially lethal blood parasite called Cytauxzoon felis.
    • American Dog Tick - Despite the name, this tick can also be found on cats and causes Rocky Mountain Spotted Fever.
    • Deer (Blacklegged) Tick - Ixodes species of ticks are often referred to as Deer ticks and can infect a cat with anaplasmosis.

    Other ticks and tick-borne diseases, including tick paralysis, also exist. Various medications will be used to treat the infection but many types of tick-borne illnesses are not able to be cured in cats. This is why using tick preventatives in cats is so important.

    Continue to 5 of 6 below.
  • 05 of 06

    Heartworms

    Mosquito on cat's nose
    Jim Schemel / Getty Images

    Transmitted through mosquito bites, heartworms commonly infect dogs but cats are also at risk. Dirofilaria immitis, or heartworms as they are more often referred to as, are microscopic internal parasites that often go undetected in cats. This is because cats only have one to three worms in their body and sometimes don't even have any adult worms. Heartworm tests are looking for special proteins called antigens that the adult female worms give off so if there aren't any, the test won't be positive even if there are immature worms in the cat. But even though there are often no adult worms to reproduce in the body, immature worms can still cause serious damage to a cat's respiratory system and eventually result in death. There is no treatment for feline heartworm disease but prevention with medications is very effective.

  • 06 of 06

    Cuterebra

    Cuterebra, a genus of botfly
    This parasite creates a hole in the skin of a cat. Smith Collection/Gado / Getty Images

    A larvae of the botfly, Cuterebra are also known as warbles in cats. There are several different species of warbles but they all burrow into the skin and cause swelling. Once the larvae is large enough, the swelling usually breaks open leaving a hole in the skin. The larvae is able to be seen in this hole before it emerges but sometimes the larvae must be surgicallly removed. The swelling and inflammation usually leads to an abscess which requires medications and cleaning to manage the infection.

If you suspect your pet is sick, call your vet immediately. For health-related questions, always consult your veterinarian, as they have examined your pet, know the pet's health history, and can make the best recommendations for your pet.