Toxoplasmosis is an infection caused by a single-celled parasite called toxoplasma gondii. The parasite is found throughout the world.
Is toxoplasmosis something that most cats carry?
A majority of cats that are permitted outside will get toxoplasmosis. The overwhelming majority of free-ranging cats will get it at some time in their life.
• Cats usually pick up toxoplasmosis from prey, such as rodents and birds
• You can also transmit Toxoplasmosis to cats that are kept strictly indoors if you feed them raw meat.
• Toxoplasmosis can also be transmitted from the mother to the kittens in utero.
Cats are the only animals that can carry toxoplasmosis in the intestine (this includes the entire cat family, such as tigers, mountain lions, house cats, etc). This is something that is unique to cats.
Any other mammal and probably any other bird can get the infection as a human can. The organism goes through the intestine (you have to swallow it in one way or the other) and then the germ passes through the intestine into the blood stream and is carried to different organs.
That's also the way it is usually transmitted to a cat. If a mouse or bird eats material that is contaminated with feline feces, the Toxoplasmosis passes into its muscle or other body organ. Then along comes another cat that eats that infected animal and the cat develops the intestinal phase of toxoplasmosis as a result. This intestinal phase is where it sheds the infective form of toxoplasmosis in its stool. It is important to note that no other kind of animal can shed toxoplasmosis in their stool.
How does toxoplasmosis affect a cat?
The infectious form of the disease is called an oocyst, this is the form of the germ that is in the cat's stool that can infect a human, another cat or another animal. The oocyst is passed in the cats stool and this infectious stage usually only lasts about two weeks and then the organism very often goes through the intestinal tract and into various organs
How do you diagnose toxoplasmosis in a cat?
It is shed for such a short amount of time in the cat's stool that the likelihood you are going to find it in a stool exam is very small. If by chance you do find it, you can give treatment to cut that shedding time. So it might go from two weeks to one week. There are certain antibiotics (sulfa drugs and others) that can be used to do this. Though the odds are that you will not be able to catch the infection at the correct time to be tested.
Once the cat has had an infection, it is relatively immune. The immunity is not perfect, but it is not likely it will become infected again. So there is a reasonable degree of immunity once the cat has been infected.
Now if the cat is sick (toxoplasmosis can cause loss of vision, it can cause seizures, liver disease, lung problems) and a vet says toxoplasmosis could be the cause, then it is advisable to do a blood test to look for antibodies.
How can you prevent the likelihood of your cat getting toxoplasmosis?
Cats should be kept indoors. They should be fed cooked food (commercial pet food) and they should be taken to the vet at least once a year for a physical exam.
What should you do to lessen the transmission of toxoplasmosis to a human member of the household?
It is important to exercise a lot of sanitation in terms of cleaning up the litter box. Ideally, pregnant women or anyone with an immune deficiency should avoid cleaning the litter box. It is important to note that it takes the oocyst on average of two to four days at room temperature to become infectious. The minute it is passed by the cat it's no longer infectious. So if you're scooping daily you will most likely avoid transmission.
If a pregnant woman has to clean the litter box, how should she go about it?
She should wear disposable, rubber gloves. After she takes the gloves off, she should still wash her hands from a minimum of 30 seconds with soap and water because there could be a small perforation in the glove.
Everyone should always wash their hands, even after wearing gloves, when handling contaminated material.
Leonard Marcus, M.D., D.V.M., is a member of the American Society of Tropical Medicine and Hygiene