Could Your Cat Really Be Making You Crazy?

Some believe the Toxo parasite may be behind crazy cat ladies everywhere

By Patrick Cullen

We’re all familiar with the crazy cat lady stereotype. While its portrayal can range from a wide-eyed old lady peeking through the thick lenses of her glasses, clutching a fat, blank faced cat against her over-sized sweater that’s equal parts wool and cat fur, to a pretty, neurotic sitcom character who’s always pictured sighing and petting her purring cat after another failed date. Regardless of the way in which she’s rendered, the crazy cat lady is defined by her combined choice of pet and weird, strung-out social ineptitude. While this is a case of the extreme, as the characteristics of cat owners occur on a spectrum, the stereotype is actually backed by science in some cases.

Could your cat really be making you crazy? While we dislike the term “crazy” as much as we aren’t fans of stereotypes, someone’s trying to make a case.


In the ‘90s, a crazy looking Czech scientist named Jaroslav Flegr asserted that a parasite was changing the way that he acted and causing him to act in ways that would suggest he was psychotic or mentally ill. The parasite, which is found in cat poop, is called Toxoplasma gondii or Toxo for short. It causes toxoplasmosis which is the reason that pregnant women have been advised by doctors to avoid exposure to cats’ litter boxes since the 1920s after it was found that it caused severe harm to the newborn or death. Without getting too scientific, when a person is infected by the parasite, his/her brain produces excess dopamine. Spikes in dopamine are believed to cause schizophrenia, OCD, and other mental illnesses, which if you think about it, have a stereotype very similar to crazy cat ladies.


Fear not, however. It’s unlikely that your cat is not giving you a serious mental illness.

In theory, your cat could be making you psychotic. A summary that looked at 38 studies of patients with schizophrenia showed that these individuals were three times more likely to test positive for Toxo antibodies in their blood, an indication that the body has activated an immune response toward a Toxo parasite it’s infected with. This is interesting but it doesn’t mean that Toxo was the cause of schizophrenia. A more recent study that looked for a link between Toxo and psychotic behavior found that cat owners were no more likely to be psychotic than people who didn’t own cats.

Comfortingly for cat owners, this study was large, with a sample size of more than 6,000 people, and it was very well controlled.
Ultimately, there’s a chance that this parasite found in a cats stool could make you act a little strange but it’s mostly theory and science has yet to prove it. What they do know for sure is that pregnant women should avoid exposure to cats’ litter boxes as the risk for harm to their newborns have been proven. You can be a crazy cat lady just don’t be a pregnant crazy cat lady.


So while all of this Toxo info is fascinating, it’s nothing to worry about for most people. Those who should worry most, perhaps, are the crazy cat ladies who thought they might’ve finally found a scientifically-endorsed basis for their crazy cat lady behavior. Sorry to say, Toxo isn’t making you a crazy cat lady. Maybe you’re just weird and have too many cats. Sorry.