Toxoplasmosis in Cats

Medically Reviewed by Vanesa Farmer, DVM on March 16, 2023
Written by WebMD Editorial Contributors
4 min read

Toxoplasmosis is a common infection from the microscopic parasite Toxoplasma gondii. It appears in many species of animals, but cats are the most common that transmit the parasite to humans. Over 40 million people in the U.S. are infected with toxoplasmosis. 

People and animals don’t usually show symptoms during or after infection, but those who are pregnant or have weakened immune systems face greater health risks.

Toxoplasma gondii is a single-celled parasite that's too small to see with the naked eye. It survives inside soil, water, raw meat, many warm-blooded animals’ bodies, and other places, but it lives longest inside cats. Infections usually last a few weeks, and most humans and animals become immune afterward. 

Cats usually get toxoplasmosis from eating wild animals or undercooked meat infected with the parasite. Toxoplasma gondii also lives inside infected cats’ feces, where it can infect other cats or animals that swallow it. Cats can’t contract the disease via bodily contact with humans or other animals — they must swallow material containing the parasite.

Toxoplasmosis often presents with no symptoms because the immune system can usually keep Toxoplasma parasites from causing sickness. However, people or animals who are pregnant or have weakened immune systems face more serious symptoms and long-lasting health risks from toxoplasmosis.

Cats may have mild symptoms upon infection. A cat with feline immunodeficiency virus or other immune problems may show more severe symptoms. These symptoms can include:

  • Diarrhea
  • Loss of appetite, or trouble chewing and swallowing food
  • Fatigue
  • Fever
  • Difficulty breathing
  • Yellow skin (jaundice)
  • Vision and balance issues
  • There may be a color change in the iris part of the eye
  • Ear twitching
  • Seizures
  • Behavior changes
  • Pressing the front of their head against surfaces

Blood tests, along with physical signs of illness and a cat's medical history, can be used to diagnose toxoplasmosis. These tests look for two types of toxoplasmosis antibodies (chemicals the immune system creates to kill outside germs and infections) in a cat's blood. The presence of one of these antibodies indicates that the cat was infected at some point and is now immune — meaning it can no longer infect other people or animals — while the other indicates an active infection.

Feline treatments for toxoplasmosis usually involve an antibiotic called clindamycin that you can give your cat by mouth. A veterinarian may also prescribe steroid creams or oral steroids for your cat’s eyes or other affected areas. These medications should help symptoms fade within a few days. If your cat doesn't get better, a different illness might be causing them.

Make sure your cat eats only properly cooked and packaged wet or dry food, and not wild rodents or other prey. Keeping them indoors will also reduce their chance of coming into contact with the parasite. Change their litter box daily to avoid your cat touching other cats' feces, which may be contaminated.

People can get toxoplasmosis from many different sources:

  • Eating undercooked or raw meat from animals or fish infected with the parasite
  • Eating unwashed fruits or vegetables
  • Using eating utensils contaminated with the parasite
  • Drinking water contaminated with the parasite
  • Disposing of cat feces and not washing hands thoroughly afterward
  • Gardening in soil or touching sandboxes that have been contaminated with infected cat feces without washing hands thoroughly afterward
  • Transmission from mother to child
  • Blood transfusions or organ transplants (very rare)

Like cats, most humans who get toxoplasmosis don't get sick at all, but babies, young children, the elderly, people who are pregnant, and people with weakened immune systems due to HIV/AIDS or cancer are more likely to show symptoms. Others may still experience symptoms, which can include:

  • Swollen lymph nodes (glands on the sides of your neck, beneath your ears)
  • Confusion
  • Headache
  • Fatigue
  • Fever
  • Body aches
  • Defects at birth or developing later in life
  • Coughing blood

Having a cat doesn’t necessarily put you at a higher risk of getting toxoplasmosis, but you can take steps to help prevent it. Avoid raw or undercooked meat or fish, raw milk, or objects and surfaces that have touched raw meat. Wear gloves while gardening and wash your hands afterward. 

Wash fruits and vegetables before eating. Change your cat's litter box daily while wearing gloves, as it takes 24 hours for Toxoplasma in cat feces to become contagious. If you are pregnant or immunocompromised, try to avoid the litter box altogether.

Most people get tested for toxoplasmosis with the same type of blood tests as cats. In rare cases, a lumbar puncture may be used to collect sample spinal fluid. Amniotic fluid tests can detect toxoplasmosis in pregnant women, and doctors can test newborns for toxoplasmosis through a physical exam.

People who are otherwise healthy usually recover from toxoplasmosis without any type of treatment. People who are sick may be treated with a combination of medications including anti-parasite and antibiotic drugs, but these medicines may be less effective for pregnant women.