body are creating some kind of a scent that the dogs are detecting. >> reporter: and dogs have other superpowers, too. some have a nose for blood sugar. they help diabetics. others can predict seizures. watch as this dog pins down 16-year-old sissy cobb, an epileptic. >> the dog is telling you don't get up. >> reporter: shannon still passes out, but clover warns her every time. >> she's a gift from god that, i mean, science can't explain this. >> reporter: a new kind of superdog with an instinct to protect as old as the friendship between man and dog. ron claiborne, abc news, cochransville, pennsylvania. >> that's not the only thing they do. they act as braces. so they brace you when you are about to fall in case you do faint. >> if you get a sugar low, they'll go get juice on command. >> if you need to call 911, they'll go and get the phone for you. and then they are just so beautiful and wonderful to be around. >> that, too. they give you a lot of love. >> i know. >> we love dogs.