To validate my opinion, I would suggest to closely observe the behavior of dogs and cats in a situation where the thieves/unknown person enter the premises of house. The dogs alarms the master whereas cats go hiding.
Anyway, both of those as pets in household can have influence on health of the inmates.
The bigger dogs usually want walk once or twice a day, when habituated for it. The dog owners are more likely to go for walk, may be under compulsion or liking, in their leisure time than the people who didn't own any pet.
If one want to shape up, dogs make better walking buddies than humans do; perhaps because dogs don't make up excuses for why they can't go on that day.
So, it has been seen that the master and children who own a dog in their household were less likely to be overweight or obese than who didn't.
Many researches establish that children raised with pets are less likely to develop allergies in their later age, or suffer from asthma or eczema. than the children raised without.
This effect was seen to be greater with cats than with dogs. The preventive effect extends to dust mite, ragweed and grass allergies.
IT has been found that just being around the pets can lower blood pressure and relieve stress. Watching pets gives pleasurable feeling and so perhaps the effect on stress and hypertension.
If somebody is allergic to dogs or cats, and there’s one in the vicinity, they are likely to cough, wheeze or sneeze. The eyes are likely to itch, nose is likely to run.
There is always risk from second hand smoking to the cats and dogs, if inmates of house smoke.
It appears that the health benefits of owning a pet is greater than that of not having one.