[ purring ] >> reporter: what if you could trade everything in your medicine cabinet for this? >> basically a furry, four-legged life support system disguised as a pet. what i'm telling you, it might be poodle instead of prozac. >> reporter: veterinarian marty becker wrote a book about the healing power of pets. and now, scientists in san francisco think they too may be on to something. they say dust found in homes with dogs may actually make kids less likely to develop asthma. the benefits of having alex, george, raven, lightning and sheldon, don't end there. so much for an apple a day. australian researchers discovered people with dogs visit the doctor less. >> lassie! >> reporter: one study found that watching this calmed nerves the connection thought to drop chemical levels linked to stress.