Dogs are sniffing out disease in animals vital to traditions of the Blackfeet tribe

Working Dogs for Conservation trainer Michele Vasquez clips a vest onto Charlie, a Labrador retriever, to let him know he's working. Dogs like Charlie will help sniff out chronic wasting disease in deer and elk scat. They will also help find mink and otter droppings that can be tested for toxic substances near illegal dumpsites. (Aaron Bolton/Kaiser Health News)

Kenneth Cook used a mallet and a chisel to crack into a pig's skull in the gravel driveway outside his home on the Blackfeet Indian Reservation in northwestern Montana.

Cook planned to use the pig's brains in brain tanning, practiced by Indigenous people for thousands of years.