The death cap mushroom, which can be fatal if ingested, is still spreading in California.

The California Poison Control System has reported five people dead and 57 ill from consuming the mushrooms between 2010 and 2015.

As noted last month by Breitbart News, the spread of the mushrooms could be assisted by wet conditions owing to this year’s El Niño rains.

Dogs are susceptible to eating the mushrooms, too; Debbie Viess, of the Bay Area Mycological Society, told Bay Area public radio station KQED that they “die in droves.” The Bay Area Mycological Society writes, “Death Caps have recently been documented growing with pine in Marin County (pine is its preferred host on the East Coast of North America) and with Tanoak (Lithocarpus densiflorus) in Mendocino County.”

Biologist Anne Pringle of the University of Wisconsin, Madison stated that the deadly mushroom has formed a connection with coast live oak and pine trees around the state, and with black oaks in Yosemite Valley.

Dr. Kent Olson, co-medical director of the San Francisco Division of the California Poison Control System, explained to KQED that people ingesting the mushroom would exhibit no symptoms for the first six to 12 hours, while the poison damages their liver. Then the severe abdominal pain, diarrhea and vomiting begins. He added, “They can become very rapidly dehydrated from the fluid losses.”

Dehydration triggers kidney failure, which in turn damages the liver.

Because a severe reaction could entail a liver transplant, Dr. Todd Mitchell, at Dominican Hospital, in Santa Cruz, is conducting tests of silibinin to save a patient’s liver so a transplant would be unnecessary. He is hoping for FDA approval by 2017.

Death cap mushrooms have a mycorrhizal relationship with trees, typified by their filaments reaching into the trees’ roots. The mushrooms absorb sugars from the trees and offer nutrients in return.