Toxoplasmosis in Cats

Stay Away From the Cat Poop and No One Gets Hurt

- Nancy Kerr

At some point, you may have heard that pregnant women should not clean litter boxes. Is this an urban legend, something made up by the person trying to get out cleaning the litter box, or is it actually based on fact?

Fact: there are several diseases that can be transmitted from cats to humans. These are referred to as zoonotic diseases. The one that may affect pregnant women is called toxoplasmosis, pronounced “tok-so-plaz-MOEsis.” It is an infection with a parasite called Toxoplasma gondii1 and is often referred to as simply “T. gondii.” A microscopic single-cell organism related to coccidia,2 T. gondii is one of the most common parasitic diseases and infects nearly all warm-blooded animals, including pets and humans.3 It is an extremely well-adapted parasite yet rarely causes significant disease to the individuals it infects.2 “Out of all the zoonotic diseases which humans can get from cats, toxoplasmosis is the most well-known and publicised one. However, there is a huge amount of misunderstanding about this disease, and also about the role the cat plays in human transmission.4

How Common is Toxoplasmosis?

T. gondii occurs worldwide, and infection in cats is widespread.2 So why is there not more mention of it? Probably because many more cats are infected than show symptoms. Very few infected cats show significant clinical signs.2 The disease is also more prevalent in outdoor or stray cats than indoor-only cats. It is seen most often in cats that are active hunters or those that are fed undercooked or raw meat.4 In contrast, infection is uncommon in pet cats that do little or no hunting and are fed primarily or exclusively commercial cat foods.2