Cuddling with kittens may fill cat-lovers with fuzzy feelings, but there’s a danger lurking beneath that furry face – a parasite called Toxoplasma gondii (T.gondii). The Schizophrenia Bulletin reports that the cat-carried parasite – common in developed nations – can infect any warm-blooded species, including humans. The Centers for Disease Control and Prevention estimates that dozens of millions of people may have got it.

Many of those who suffer from the parasite may never develop any symptoms, but those with a weaker immune system may end up suffering from all sorts of problems as t-gondii has been linked to everything from toxoplasmosis to blindness, mental illness, even death.

Two studies exploring mental health issues have found links between cats and schizophrenia. Researcher Wendy Simmons compared two previous studies linking childhood cat ownership and the development of schizophrenia later in life and an unpublished survey on mental health from 1982. Results found that cat exposure in childhood may be a risk factor. In a press release, the authors of the study reported: “Cat ownership in childhood has now been reported in three studies to be significantly more common in families in which the child is later diagnosed with schizophrenia or another serious mental illness.”

In a second study, the Psychiatry Department of the Academic Medical Center in Amsterdam analyzed the findings of 50 published studies to confirm the link between the parasite and mental disorders. They found that those who were infected with T. gondii were twice as likely to develop schizophrenia. They also found an association with addiction and obsessive-compulsive disorder. But, the researchers, far from telling cat-owners to get rid of their cats, state that cat-owners should approach the findings with caution.

Rather than limit cat contact, children are urged to keep their cat indoors and cover the sandbox when not in use.