A New York hunter died of a rare brain disorder he may have caught after eating squirrel brains, according to a new report.

The 61-year-old was brought to Rochester Regional Health hospital in 2015 saying he was having trouble thinking clearly, was losing touch with reality and could no longer walk on his own, researchers said in an Oct. 4 report on on the case, according to Live Science.

Based on an MRI, the unnamed man seemed to have a variant of Creutzfeldt-Jakob Disease, a degenerative and fatal brain disorder that is commonly contracted by eating meat from cattle affected by “mad cow disease,” doctors found.

In this case, eating contaminated cow meat wasn’t the issue — another animal was to blame.

The man’s family said he’d been known to eat squirrel brains — though it’s unclear if he dined on the whole brain or squirrel meat that had come in contact with the contaminated brain.

Dr. Tara Chen came across the unusual case when she was tasked with doing a report on cases of CJD seen at the hospital over the last five years.

The incurable neurological disorder affects about one in a million people each year worldwide, according to the National Institutes of Health. There are about 350 cases in the US per year.