9 tips to stop pets from spreading infections to humans

Pets can be a source of disease-causing bacteria, especially to young children, pregnant women, seniors and those with weak immune systems, but there are ways to reduce the risk.

While pet ownership has health, emotional and social benefits, the animals can also transmit infections to people, posing an underappreciated risk, according to medical and veterinary researchers. 

In Monday's Canadian Medical Association Journal, two veterinarians and a physician describe types of common infections, how pets transmit them, prevention and the role of health-care providers.

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Dogs, cats, rodents, reptiles and amphibians can transmit salmonella, multidrug-resistant bacteria (including Clostridium difficile), Campylobacter jejuni and other diseases. Parasites such as hookworm, roundworm and Toxoplasma are also on the list of risks.

Dr. Jason Stull, an assistant professor in the department of veterinary preventive medicine at Ohio State University in Columbus, Ohio, and his co-authors' suggestions for prevention include:

• Wear protective gloves to clean aquariums and cages and to remove feces.
• Wash hands after contact with pets.
• Discourage pets from face licking.
• Cover playground sandboxes when not in use.
• Avoid contact with exotic animals.
• Clean and disinfect animal cages, feeding areas and bedding regularly. For example, change cat litter boxes daily and keep them away from areas where food is prepared and eaten. Similarly, don't dispose of aquarium water in sinks used to prepare food.
• Wait to acquire a new pet until a sick person's immune status has improved.
• Consider limiting contact with animals in medical settings, such as therapy and visitation animals.
• Schedule veterinary visits for all pets regularly, including to control and prevent parasites. 

The other suggestions offered more specifics on personal hygiene, types and ages of pets and pet health. For example, avoid contact with dogs and cats less than six months old, reptiles, amphibians, rodents and chicks or ducklings, especially in homes with very young children or high-risk patients, including those being treated for cancer. 

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"Young dogs and cats can be fantastic pets for the average person. But if there is an individual who is severely
immunocompromised, that may not be the best choice," Stull advised. "It may make more sense to get an adult or mature animal that's going to be less likely to carry some of these zoonotic [animal-related] organisms."
  
When a child is diagnosed with cancer, the family may seek a new pet to help cope. "In most situations there are options for finding a pet for that household, but it requires having a conversation with physicians and veterinarians," Stull advised.

Stull pointed to research on salmonella infections, such as how 31 per cent of reptile-associated salmonellosis cases in one study occurred in children under five. Direct contact with those animals isn't needed to spread the infection.

Hedgehogs and chinchillas are also among the "highest risk" animals, Stull said.

There isn't high-quality data on rates of pet-sourced infections, because governments don't generally track diseases 
transmitted by companion animals beyond rabies.

Pet-sourced infections have also been reported in organ donors and recipients, said Bruno Chomel, who researches 
veterinary public health and "zoonoses" at University of California, Davis, School of Veterinary Medicine. Chomel was not part of the new review.
 
"We are not saying that you should get rid of the pet," Chomel told Reuters. But if your immune system is compromised, he added, "don't take in a stray pet or a kitten with fleas, and if you have young toddlers, don't take an iguana as a pet."

The authors also suggested doctors ask about pet contact and counsel patients on safe pet ownership. Most patients do not ever recall being asked if they have pets," Stull said.