Should we let our pets lick us?

Today’s guest blogger is Shelley C Rankin, PhD, an associate professor CE of Microbiology at the University of Pennsylvania, School of Veterinary Medicine.

Have you ever seen those Facebook posts and YouTube videos of animals licking small children? I recently saw one called “Just a big bully and his best friend”. The video showed a tiny baby lying on the belly of a giant pit bull while the dog licked the baby’s face. It sure was cute and put a smile on my face! Some people I know would have been horrified. I mean, who puts their baby on the belly of a giant dog breed? That was not my first thought, though. All I could think was, “Do those parents know what’s in that dog’s mouth?”

There’s a pretty long list of bacteria, viruses, fungi and parasites that can be transmitted from animals to humans. The scientific term for these is “zoonoses,” and they are more common than you might think. In fact, 61 percent of all infectious agents are zoonotic. And when it comes to domestic carnivores (dogs and cats to you and me), then almost 70 percent of the pathogens that infect them (or are carried by them) can also infect humans.

All of our pets, including dogs, cats, birds, reptiles and small furry mammals such as rabbits, hamsters, gerbils, and rats may carry microorganisms that can cause a variety of illnesses in humans. The illnesses we can get from being licked, or bitten, by an animal carrying one or more of these organisms can be very mild, but sometimes they can be very serious. There are some people that have an increased risk of getting sick if they come into contact with an animal that has, or carries, an infectious disease organism. Babies and young children obviously fall into that category and are at higher risk than adults because their immune systems are not fully developed.  

The mouths of dogs and cats are not “cleaner” than human mouths. That is a myth. It’s also a fact that each and every mouth is a little different, depending on what that animal eats, drinks and has been exposed to generally in its environment. There are a few bacteria that we worry about more than others, just because we see them causing serious infections more often following an animal bite. These are Pasteurella and Capnocytophaga, both of which are commonly isolated from cat and dog bite wounds. When I think about what’s in that mouth when I see babies being licked by a big slobbery dog, my list also includes Salmonella, Campylobacter, E. coli, Leptospira, Giardia, Cryptosporidium and, of course, Staphylococcus.

We recently showed that methicillin-resistant Staphylococcus aureus (MRSA) can be isolated from animals that live with infected humans. We screened 196 pets (dogs, cats, reptiles, birds, fish and pocket pets) that lived in households with a MRSA-infected human. We found MRSA in 8 percent of those animals and identified the mouth as the most common carriage site. That's good enough for me!

The best tactic to avoid these types of infections in small children is to stop letting your pets kiss and lick them — if you can help yourself. It’s just so cute to watch! Is there a risk? Absolutely. Should you let your pets lick your children? No. Will you? Probably. But try to limit it if you can.

Here are some other tips to help protect you from diseases.

• Try and wash your hands after handling pets.

• Always wash your hands with warm soapy water after handling reptiles.

• Make sure your pet is from a reliable source and get as much health information as you can before you bring it into your home.

• Feed your pet commercial animal food. Do not feed them raw meat or unpasteurized dairy products.

• It is advisable to avoid the BARF (bones and raw flesh) diet.

• Control fleas, lice, flies and cockroaches in your pet’s environment. Your veterinarian can assist you in the control of these parasites.

• Do not allow your pet to scavenge, eat wild animals, birds or rodents.

• Do not let your pet drink from the toilet.

• Do not allow pets to lick you in the face.

• Try not to come in contact with your pet’s feces, urine or other body fluids.

• Clean litter boxes daily and cages and tanks frequently. Avoid breathing dust from litter trays and bird cages.

• Pick up dog feces and dispose of it properly.

• When cleaning fish and reptile tanks wear gloves and dispose of them after use.

• Have all new animals examined by a veterinarian.

• Ask your veterinarian about a vaccination program for your pet.


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