Photo Courtesy Canto/AdobeStock
What is Toxoplasmosis?
Toxoplasmosis is the name of the clinical disease caused by the parasite Toxoplasma gondii. It is most often associated with cats but can infect all warm-blooded species including humans. It is a zoonotic disease, which is an infectious disease or condition that can be passed between animals and humans. Zoonotic refers to zoonosis, which is a Greek term meaning "animal sickness".
You have probably heard the warnings given to pregnant women about cleaning litterboxes and the dangers of ingesting raw/undercooked meat or milk products.
But should you be concerned about how this parasite affects your cat?
Any questions or concerns about toxoplasmosis and its effects on humans should be addressed with your physician.
How Does My Cat Get This?
T. gondii is carried by many animals, but cats are the only definitive host (where the parasite reaches the adult stage and is able to reproduce). Other animals have a specific enzyme that prevents the parasite from maturing.
Infected prey animals, raw meat, and soil can hold tissue cysts called oocysts, which are egg-like structures containing millions of immature T. gondii. When your cat ingests the parasite by eating an already infected animal or picking it up from infected soil, the oocysts transform into developing tissue called tachyzoites. These tachyzoites can pass to different areas of the body, including muscles, the heart, and other organs.
How Will I Know if My Cat Has Toxoplasmosis?
An otherwise healthy cat might not develop or display any signs. Cats with weakened immune systems, pregnant cats, and young kittens are the most susceptible.
Pregnant cats can pass the parasite to their unborn, resulting in complications that include genetic abnormalities, weak or small kittens, or loss of the pregnancy.
The most common signs a cat with an infection might show include depression, acting tired or listless, or appearing to have muscle or stomach pain. Your cat may have a cough, a fever, stop eating, or have a bloated abdomen, along with vomiting and diarrhea. Eyesight problems or inflammation of the eyes might be present.
As previously stated, the infection caused by the parasite can involve internal organs, and respiratory infections are common.
In a study of cat breeds, Persian, Birman, Ocicat (a domestic breed that has coat markings resembling an ocelot), and Norwegian Forest cats were four to seven times more likely to have positive results when testing for toxoplasmosis.
Both male and female cats can be affected by the parasite.
How Is Toxoplasmosis Diagnosed?
Based on the signs your cat is having, blood work, fecal sample analysis, tissue biopsy, urinalysis, and serum titer tests may be carried out by your veterinarian. More serious cases may require more extensive testing, including radiographs (X-rays) and eye examinations.
What if My Cat is a Hunter But Isn’t Sick?
Although this parasite is common, not all cats will get infected. And even if they do, most healthy cats do not become seriously ill.
After exposure, oocysts can shed for several weeks. A healthy cat can live with the parasite that causes toxoplasmosis for years and you may never know it.
Because the tissue cysts that cause toxoplasmosis are not easily destroyed, the parasite can remain with your cat and become active again in the future, with or without illness. Cats that are otherwise healthy tend to have better outcomes.
How Is It Treated?
Antibiotics will likely be prescribed. If your cat is on any type of immunosuppressive medication, it will most likely be stopped. Supportive therapy and proper medication for any symptoms will be recommended, as appropriate.
Cats can begin to show improvement within 1-2 days of treatment. Depending on the seriousness of a cat’s infection, a full recovery is possible.
Keeping litterboxes clean, not allowing your cat to hunt in the yard, and not feeding raw diets will help.
At the time of this writing, studies for vaccinations against toxoplasmosis are not complete, and a vaccination is not yet available.