It’s pretty well established that health is affected by pet ownership. Dogs seem to be pretty unequivocally good at improving their owners’ health, although my brother-in-law’s mother did suffer a broken hip when she tripped while walking her little Buttons. But older people who own dogs (or are owned by dogs) usually are more active, and have better general health by measurements of weight, bone density, cholesterol levels, blood pressure, hospitalizations and ER visits, all of which are correlated with staying physically active. People with epilepsy and pets, either cats or dogs, are less likely to suffer sudden death, and even untrained dogs can tell if people with Type 1 diabetes have dangerously low blood sugar.
Psychological effects are harder to measure, although most pet owners will claim large effects on their mental health. But interestingly, one study of people with Chronic Fatigue Syndrome showed no difference in self-reported fatigue scores between pet owners and non pet owners.
Cats get mixed reviews, with a couple of recent studies showing worse outcomes in people with heart disease. Family ownership of either dogs or cats may be correlated with less asthma or allergies in kids, but the studies are mixed, about 50/50 no relationship or some decrease in incidence.
Of course all of this is correlation, which does not equal causation! There are lots of confounding factors, including the ability to afford pets. Higher and more stable income is definitely associated with better health.
I may sound like Captain Obvious here, but exotic animals, especially the biting/stinging sort, don’t seem to have anything good going for them as far as health benefits to the owners, and ownership of an exotic animal rarely seems to go well for the animal. My sister Susan supports Tampa’s big cat rescue. Some of their stories are really sad. Please check out their link!