Study finds cats linked to increased mental health problems in young children

A study tracking 1,900 Spanish families in the INMA Project links cat ownership at ages four to five with increased mental health risks. Published in the World Journal of Pediatrics, the research shows these children are 37% more likely to experience internalizing issues like anxiety, and 27% more likely to exhibit externalizing behavioral problems by age seven or eight. Conversely, continuous ownership of small pets like fish or hamsters offers protective benefits, while dogs show no significant correlation.

INMA cohort study design

• ▪The observational study on childhood pet ownership and mental health was published in the World Journal of Pediatrics in 2025.
• ▪Among the Spanish households surveyed in the INMA Project study, 52.3% owned pets, including 19.1% with dogs, 8.7% with cats, 14.8% with birds, and 28.6% with other animals.
• ▪The INMA Project cohort study monitored approximately 1,900 households in Spain from pregnancy until children reached 6 to 7 years of age.

Cat ownership mental health risks

• ▪Children who lived with a cat at ages 4 to 5 were 27% more likely to exhibit externalizing behavioral issues, such as acting out or rule-breaking, by ages 7 or 8.
• ▪A study published in the World Journal of Pediatrics found that children who had a cat at home at ages 4 to 5 were 37% more likely to show internalizing mental health problems, such as anxiety and sadness, by ages 7 or 8.
• ▪Researchers suggest the link between cats and behavioral issues may occur because lower-maintenance cats provide less interactive play, or because families with children who already have emotional needs are more likely to choose cats.

Toxoplasmosis parasite behavioral effects

• ▪The parasite Toxoplasma gondii, which is commonly carried by cats and shed in litter box waste, has been linked in past research to behavioral problems and psychiatric disorders, including bipolar disorder and schizophrenia.
• ▪The 2025 observational study on childhood pet ownership did not perform biological testing on any children or cats to detect the presence of the Toxoplasma gondii parasite.

Small pets protective benefits

• ▪Researchers state that small pets like fish, turtles, and hamsters demand stable, easy contact that helps children learn responsibility, empathy, and self-control.
• ▪Having small pets such as hamsters, rabbits, turtles, or fish consistently throughout early childhood was associated with a protective effect against mental health problems in children.

Continuous pet bond importance

• ▪In the INMA Project study, children who had never owned a pet showed the most positive overall mental health scores.
• ▪Children who lived with small pets on a regular, continuous basis achieved better mental health scores than those who only had them intermittently.

Debatable claims

• ▪Parents of young children should avoid keeping pet cats
• ▪Owning a pet benefits a young child's mental health