Pet Owners Beware: Dog-Killing Parasite Discovered in Southern California

Experts caution dog owners against allowing their pets to swim in the Colorado River.
Scientists at UC Riverside have verified for the first time the presence of a potentially deadly dog parasite in a section of the Colorado River that flows through California.

The parasite, Heterobilharzia americana, is a flatworm commonly referred to as liver fluke. Previously found almost exclusively in Texas and other Gulf Coast states, it has never been reported this far west. The worm can cause canine schistosomiasis, an illness that impacts the liver and intestines of dogs.

“Dogs can die from this infection, so we are hoping to raise public awareness that it’s there,” said UCR nematology professor Adler Dillman. “If you’re swimming in the Colorado River with them, your pets are in peril.”