A surprising new study is showing that cuddling with your furry, four-pawed friend may cost you your health.

A new study released from the Centers for Disease Control and Prevention today says that people are suffering from serious complications from what’s called “cat-scratch disease,” especially when it is not properly treated.

The bacterial infection is passed between cats and fleas and can be spread to humans through scratches, bites or licks. The CDC says the disease is rare, but they have seen an increasing amount of people getting seriously ill. Side effects include headaches, fever and swollen lymph nodes, which can affect the heart and brain. Cats that are less than a year old are more likely to have the bacteria.

The best way to avoid the disease is to wash your hands often after handling your pet. Each year 12,000 people are diagnosed with cat-scratch disease.