If your clients need some motivation to clean out the litter box sooner rather than later, a new study may provide just that.

The study, published in the journal Schizophrenia Research in April, suggests that owning a cat in childhood is more common in families where a child became mentally ill.

The culprit is Toxoplasma gondii (T. gondii), a parasite found in 60 million people in the United States, according to the Centers for Disease Control (CDC). It can be transmitted through contact with cat feces and through mother’s milk, as well as through contaminated food or water.

Researchers used the National Alliance for the Mentally Ill (NAMI) questionnaire used in two previous studies (and which resulted in the same outcome) to see if they could replicate the findings. The results were the same.

“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,” wrote study authors  E. Fuller Torrey, MD, and Executive Director of the Stanley Medical Research Institute and Robert H. Yolken, MD,  of Johns Hopkins University School of Medicine, reported CBS News.

A footnote: one of the previous studies, also conducted by Torrey and Yolken, provides a caveat lest owners be concerned about changing behavior. One author owns two cats. The other author allows a neighbor’s cat, “…who believes she owns all houses in the neighborhood, to visit regularly."