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Common Parasites in Cats


Parasites are creatures that live inside or on another organism, known as the host, and feed on it and at the same time produce harm. Parasite prevention is critical for a healthy cat, and having an understanding of potential risks may help protect your cat from a range of diseases.

The types of parasites that afflict cats are classified as external or internal parasites. The ones found on your cat’s hair and skin are external, whereas internal parasites live inside their body.



Fleas are little insects that live on the skin and feed on the host’s blood, causing soreness. They’re considered one of the most hazardous pest groups because, in addition to being a nuisance because of their constant biting, they may also transmit several rather serious diseases like tapeworm and bacterial infections.

All cats are susceptible to flea infestations, but they are more common in outdoor cats, cats that live with other pets who do have access to the outdoors, and cats who live in multi-pet households. Although frequent scratching, licking, or biting of the skin are classic indications of fleas, cats are known to disguise flea infestations.

Fleas, luckily, are easy to treat once they’ve been identified. Your veterinarian can supply you with spot-on treatments that are both safe and simple to use, as well as instructions on how to apply them and how often to use them. Collars for fleas are also available and might be useful. Finally, there are medicines that may be given to your cat to kill any fleas they may have.


These egg-shaped arachnid parasites have eight legs and range in size from 1mm to 1cm. Ticks are more common in locations where there is a lot of wildlife, making it simpler for cats to catch them. They are active throughout the year, although pets are more likely to come across them in the spring and fall. Lyme disease and Mycoplasma can be transmitted by ticks to cats and even people.

Ticks are large enough that you can detect with your hands while checking for bumps and painful areas on your cat’s skin. A tick feels like a little bump on their fur surface. The most prevalent areas where you’ll be able to find them are the head, neck, ears, and legs.

Tick repellents are available in a range of formulations. Over-the-counter medications like spot-on and collars, as well as prescription medications from your veterinarian, are all options. It’s important to know that flea and tick medications designed for dogs should never be used on cats as they might be toxic to them.


Mites are little spider-like parasitic organisms that live on the skin and in the ear canals. They can cause a lot of irritation, skin issues, and bacterial infections. The most frequent mite seen in cats is the ear mite. It dwells in the ear canal, although it can also be found elsewhere on the body. Other mites are responsible for scabies and trombiculosis.

The most common indicators of mites in cats are incessant scratching, head shaking, licking, or biting, and all of these can result in sores, scabs, inflammation, and hair loss.

The best strategies to keep mites at bay in your cat include anti-parasite medicines, observation, and regular grooming. If you see signs of these parasites, you should consult a veterinarian, who will determine the type of parasite and provide the necessary and specific treatment.


Internal parasites include worm-like parasites like roundworms, tapeworms, heartworms, and hookworms, as well as protozoan parasitic species including giardia, coccidia, and toxoplasma.


Giardia duodenalis is a protozoan parasite that causes giardiasis, it is a one-celled parasitic organism -rather than a worm, bacteria, or virus- that attaches itself to the intestinal wall and causes the sickness. Cats are infected by eating the parasite’s larvae, which are found in infected animals’ excrement.

This disease can result in diarrhea, greasy feces, and weight loss over time. The stool may be mushy or watery, with a green tint and blood. The presence of mucus in the feces is fairly common. Diarrhea can be a chronic or recurring disease. Cats suffering from the illness may become more sedentary and maybe develop a fever.

If your cat has been infected with giardiasis, your veterinarian will develop a course of action and prescribe the medicines that will eliminate the parasite effectively, as well as treatment for dehydration and diarrhea if these symptoms are prevalent. Maintaining clean surroundings and proper hygiene are the best ways to avoid giardiasis.


The organisms Isospora felis and Isospora rivolta, which are one-celled parasitic organisms, cause coccidiosis. Cats get infected from cysts found in excrement, ingesting other animals (such as mice and flies), or dirt in most instances. The typical coccidia species that infect cats cannot infect humans.

A large majority of cats infected with coccidia will present no clinical symptoms, however, kittens and adult cats with weaker immune systems may suffer from severe watery diarrhea, dehydration, vomiting, and lack of appetite. Coccidiosis is only detected after a comprehensive examination of the feces.

When a cat is diagnosed with coccidiosis, the veterinary doctor will specify which anti-parasitic medications will work to treat it. Other auxiliary treatments may be necessary; however, most cats will not need them.


Toxoplasma gondii, a single-celled parasite prevalent in cats that seldom causes illness, is the cause for toxoplasmosis. This parasite’s cysts found in raw meat (from infected prey) infect the majority of cats. While most healthy people are unaffected by toxoplasmosis, those with weakened immune systems and pregnant women are more vulnerable.

Toxoplasmosis symptoms are usually seen in cats with weakened immune systems, such as kittens or cats infected with FeLV or FIV. Symptoms include fever, exhaustion, and a lack of appetite. Other symptoms, such as pneumonia if the parasite attaches to the lungs or jaundice if it attaches to the liver, may occur.

Antibiotics are the typical treatment for toxoplasmosis, and steroids may be used if swelling is present. Your veterinarian will prescribe medicine as soon as the condition is detected, and it should be continued for a few days after the symptoms have faded.


Roundworms are large worms that live in the intestines of their host and cause ascariasis, these are common in cats. Roundworms are spread by the ingestion of larvae found in infected animals’ feces or in prey such as birds, rats, and cockroaches, which serve as egg hosts. Humans can be infected with roundworms, although the disease rarely develops.

Roundworms’ most common symptoms include diarrhea, lethargy, weight loss, and vomiting. In cats with few worms, there may be no signs of sickness, however, they may be found in the feces or vomit.

Because ascariasis symptoms may not be evident, yearly wellness exams, including stool analysis, are essential. The infection is usually easy to treat after it has been detected, requiring only a few doses of special dewormers. Cats are always at risk of becoming infected with roundworms, this makes regular deworming a great preventative measure, especially if they are allowed outdoors. Another good habit is to maintain a clean litterbox and managing any pest infestations.


They’re flat, long, and segmented and cling to the small intestines. The Dipylidium caninum species is the most common cause in cats but there are several different types that may cause infection. Cats can only be infected through ingestion of a parasite-carrying flea, which generally happens during grooming as a response to flea bites. Tapeworms are unlikely to cause infection in humans.

The most obvious symptom of infection is the detection of worm segments, or proglottids, in the feces and around the anus; some vomiting (including proglottids) is possible if the worm makes its way to the stomach, and sometimes weight loss may also be present.

Tapeworms are treated with dewormers, either oral or injectable. The most effective way to keep cats from getting tapeworms is using flea control treatments, particularly with cats that have outside access.


Dirofilaria immitis, or heartworm, are protozoan parasites that reside in the heart and the blood vessels that surround it. Even though cats are more resistant to heartworm infection than dogs, it can nonetheless happen. Infected mosquitoes transmit the disease by injecting the larvae into the circulatory system of the pet, where they travel for months finally establishing themselves in the heart and pulmonary arteries.

Heartworm infection in cats may not exhibit symptoms until it has progressed a lot. The most noticeable symptoms of infection are fast breathing and coughing episodes, sometimes with vomiting, poor appetite, and loss of weight. Cats may experience fainting spells, seizures, or strain to walk. Sometimes, sudden collapse and death may actually be the first signs of heartworm infection.

Sadly, in cats, there is no specific medicine for the treatment of heartworm, and the medicine used in dogs is not suited for cats. The conventional approach involves the treatment of symptoms and stabilization of the pet which, if deemed critical, might lead to hospitalization. Nevertheless, the infection may be easily averted by taking preventives that exist in various formulations. Always contact your veterinarian first and have your cat examined for heartworm before administrating any medication.


These parasitic worms are small (one-eighth of an inch) and very thin, they feed on the host’s blood and tissue fluids through mouth hooks that let them grab on to the walls of the intestines. The most common worms detected in cats are Ancylostoma tubaeforme and Ancylostoma brasilience, although the dog hookworm can also infect cats (Ancylostoma caninum).

Cats become infected by swallowing the eggs (through grooming), consuming contaminated prey, or when the larvae burrow through the skin. Kittens may get infected through their mother’s milk while nursing. Internal infection in humans is not feasible, however, larvae can burrow into the skin causing irritation. The usual symptoms of infection in cats are anemia, weight loss, diarrhea, dull hair coat, and bloody stools.

Hookworms are best recognized by means of a stool analysis and when a veterinarian has made the call, dewormers are used for treatment. Parasite preventives, periodic deworming, regular litter box cleaning, and good hygiene are suggested for cats at risk.