Diagnosing Cat Toxoplasmosis

Caused by the Toxoplasma gondii parasites, toxoplasmosis is one of the most common parasitic invaders in mammals and is infamously known to infect cats. Most cats that are infected with toxoplasmosis usually don't have symptoms unless they acquire clinical disease toxoplasmosis. Early diagnosis of cat toxoplasmosis can help a cat recover better from the infection.

Cat Toxoplasmosis Explained

A cat usually becomes infected with toxoplasmosis when he ingests a Toxoplasma gondii parasite, by eating an animal that's infected with it. Cats can also become infected by coming in contact with feces that contains the oocysts (eggs), which is usually accidental. The parasite then thrives in the wall of a cat's small intestines and begins an intraintestinal cycle. In as little as three days after ingesting the parasite, a cat will begin to pass oocysts in his stool for up to two weeks. The oocysts are very resilient and have been known to survive for a year.

The dangers of toxoplasmosis lay in the fact that the parasite that causes the infection releases organisms that place themselves deep into the walls of a cat's intestine and multiply. The organisms then travel to other parts of a cat's body until his immune system halts them, sending it into a dormant stage. When the organism goes into a dormant stage, it creates cysts in a cat's muscles and brain that have an organism that multiple slowly, known as bradyzoites.

Diagnosing Cat Toxoplasmosis

The first step in diagnosing toxoplasmosis in a cat is taking him to a veterinary clinic for a thorough physical examination. The vet will ask about the cat's history and symptoms to determine if the infection is acute or chronic. A cat with toxoplasmosis will typically have a fever, a lack of energy and a loss of appetite. Other symptoms of the infection are dependent upon what part of the cat's body the parasites have infected. Any abnormalities a cat displays can help a veterinarian diagnose not only the parasitic infection, but the part of a cat's body that needs particular attention.

The vet will take sample of the cat's blood to see the levels of IgG and IgM antibodies to the Toxoplasma gondii parasite within it. A cat that has a higher level of IgG antibodies to the parasite, but is otherwise healthy and not passing oocysts in his stool, can tell a veterinarian that the cat had been infected with toxoplasmosis, but is now immune to it. If a cat, however, has IgM antibodies to the parasite, he has an active infection. If antibodies aren't found at all in a blood sample, the cat is still able to become infected and may shed parasite eggs in the next couple of weeks.

The most definite diagnosis comes with examining a cat's tissues under a microscope to see if there are changes in its pathology or the presence of tachyzoites that would cause cysts in the tissue.

Taking a cat to a veterinarian's office when he first begins to display unusual symptoms can help diagnosis a toxoplasmosis infection before it becomes dangerous and untreatable.