Elderly patients may benefit from even short "pet therapy" encounters, a new study suggests. That means facilities don't have to invest in kennels and round-the-clock pet care to help residents improve their mental health. Residents who spent 30 minutes with a therapy i dog, either once or three times a week, scored significantly lower on loneliness measurements than those who spent no time with the dog, according to a study published in a recent Journal of Gerontology: Medical Sciences. Pet therapy may not work magic for everyone: Participants in the study had all indicated having past ties to pets and a desire to have a pet.