The family pet could present an infection risk, researchers say, especially to children, pregnant women, seniors or anyone with a weakened immune system.
Catching an illness from a pet is more common than previously thought, they say in a report in which they suggest the need for new guidelines about getting or having a pet to reduce the possible health risks.
"Studies suggest physicians do not regularly ask about pet contact, nor do they discuss the risks of zoonotic diseases with patients, regardless of the patient's immune status," says Jason Stull of Ohio State University, co-author of the study review published in the Canadian Medical Association Journal.
Zoonotic diseases are those that can be passed from animals to humans, and include examples such as salmonella, parasitic diseases such as hookworm, and drug-resistant bacteria.
The researchers reviewed and analyzed around 500 studies from around the world to come up with recommendations for ways families can reduce the risk of infection and disease by choosing what kind of pet they keep or how they live with the pets they already own.
"It's all about safe pet ownership," Stull says. "There are very few situations in which a person couldn't or shouldn't have some type of pet if they wish. It's about matching the right species with the right person and taking the appropriate precautions."
Because different pets, be they cats, dogs, birds, rodents, fish, amphibians or reptiles, can carry different diseases and will be more or less infectious at different points in their lives, the researchers suggests prospective pet owners consult with both their doctor and with a veterinarian to determine the safest kind of pet for a family.
And doctors should reach out to vets for information on the potential health risks of particular pets, especially if their patient has a weakened immune system, Stull says.
For example, he cites amphibians and reptiles as being responsible for around 11 percent of all sporadic salmonella infections among patients less than 21 years of age.
Such pets can transmit zoonotic diseases without direct contact with humans, he notes.
Salmonella can also be transmitted to humans by cats, dogs and rodents, the researchers say.
While they do not suggest people give up on pet ownership - studies have confirmed pet ownership can have significant health benefits - they do recommend people at high risk and their families remain vigilant about their pets' health and take precautions to reduce possible infections. Frequent hand washing, discouraging face licking, keeping litter boxes away from food preparation areas and keeping cages and bedding clean are some of the simple steps that can help reduce infections, they note.
"Pets do so much good for people in terms of mental, physical, and emotional health," Stull says. "But at the same time, they can transmit diseases to us. Physicians, veterinarians, and the public have to work together to make sure the benefits outweigh the risks."