Coccidia in Cats

What are coccidia, and coccidiosis in cats

Coccidia are a group of single-celled protozoa found within the intestinal lining of kittens and cats. These often cause an intestinal-tract infection called coccidiosis ^{[1, 2]}.

Kittens, and older cats that are stressed or have a weak immune system are more likely to be affected by coccidia ^{[1, 2]}. Young cats less than six months old are more likely to get affected due to their immature immune system ^[2].

Signs and symptoms

Although most cats in the US carry the parasite, they do not develop any symptoms ^[2]. These cats are not considered to be in immediate danger unless they already have weakened immune systems impaired by stress or bacterial, viral, and fungal infections ^[2].

A sick cat may show the following visible signs:

• Watery stool with blood or mucus ^{[1, 2, 3]}
• Vomiting ^{[1, 3]}
• Redness, swelling of the eye, unevenly shaped or small pupil, excessive tears (uveitis) ^[3]

Look out for the following behavior changes:

• Eating less than normal (anorexia) ^[3]
• Lethargy or panting (may be caused by dehydration) ^[3]
• A reduction in overall activity, abnormal gait, and a tendency to hide behind walls and furniture (often because of abdominal pain) ^[3]

For a kitten, the weaning process can sometimes be stressful and may lead to parasitic infections ^[3]. Sometimes a stressed kitten may start displaying symptoms of coccidiosis between two weeks and six months of age ^[3].

Causes: How do cats get coccidia

Though it is mostly caused by the parasites Isospora rivolta and Isospora felis, some species of Toxoplasma, Besnoitia, Hammondia, and Sarcocystis may also be responsible ^{[1, 3]}. The infection can spread in the following ways:

• Immature coccidia or oocysts (cysts containing zygote formed by the parasite) can enter the body through direct contact with feces of an infected cat ^[1]. Kittens may come in direct contact with their mother’s feces during nursing and get infected if the mother is passing infective oocysts in her stool ^{[1, 2]}.
• A cat may develop coccidiosis by consuming an infected mouse ^[1].
• A kitten or puppy can contract the disease from other infected kittens, and it usually happens in animal shelters and other breeding facilities ^{[1, 2]}.
• The parasite might also contaminate food, spreading in cats and other animals who eat it.

The process of immature coccidia sporulating into a developed oocyst, either re-infecting the same cat or spreading to other cats, can take place within as little as 6 hours, though it usually takes 7-10 days ^[1].

Is it possible to prevent coccidia

Though prevention may not always be possible, taking the following measures may help with keeping the infection from spreading further:

• Isolate an infected cat from other pets ^[2].
• Keep their litter boxes clean during treatment for preventing the parasitic infection from spreading through the household ^{[2, 3]}.
• Sterilize the materials used for handling your cat, including their boxes, with bleach and warm water to prevent reinfections ^{[1, 3]}.
• Try to keep your cat indoors to reduce the chances of getting coccidia from infected rodents ^[6].
• Give it high-quality foods to boost its immune system ^[6].

Diagnosis

If any of the above symptoms are present in your cat, take it to a vet immediately ^{[2, 3]}. After going through its medical history, your vet may perform a complete physical examination along with an evaluation of its symptoms ^[3].

Tests include a stool analysis, where the sample is thoroughly observed because coccidia eggs are hardly visible, as they are much smaller than the intestinal worm eggs ^{[1, 2]}. Since an infected cat might not always shed oocysts in feces, blood and urine tests would likely help diagnose the infection ^[2].

Treatment of coccidia in cats

A mild infection may need no treatment ^[3]. However, in severe cases, treatment involves lessening the symptoms, monitoring your cat’s condition, and controlling the cause ^[3].

Treating with antibiotics

Vets usually recommend Sulfa-class antibiotics for treating feline coccidial infection because most cats readily take these for their pleasant taste ^{[1, 2]}. These oral medications are generally given for one to two weeks ^{[1, 3]}.

Supportive treatment to relieve complications

If your cat shows signs of diarrhea and dehydration, it may need to be hospitalized and kept under observation ^[3]. Intravenous fluids may be administered to rehydrate and stabilize its condition ^[3].

Can coccidiosis be cured completely

Although most cats treated with antibiotics recover from coccidial infections, they do not become fully resistant to the parasite ^[2]. They can become carriers so that the parasites spread through their stools, increasing the risks of re-infections all through their life ^[2].

Is it contagious to humans

The Isospora species, the most common in cats, are not known to infect humans ^[1]. However, the less common Cryptosporidium can affect people with weakened immune systems, and Toxoplasma infections are particularly dangerous during pregnancy ^[1]. These may spread through contaminated water or meats.

Coccidial infection cannot be passed from cats to dogs because a dog is less likely to ingest the parasite from soil, swallow cat feces, or eat intermediate hosts like a mouse ^[5]. Puppies are often less resistant because of their maturing immune system.