Pet owners usually fall into one of two camps when it comes to being affectionate with their animals.
Either they give them lots of hugs and kisses without a care in the world, or they’re cautious and keep animals’ mouths far away from their faces.
If you fall into the former camp, are you putting your own health at risk?
Any disease that can be spread from an animal to a human is called “zoonotic”.
Common pets have zoonotic diseases that mightn’t harm them, but can definitely harm you.
Giardia, a common soil- and water-borne disease that can result in diarrhoea in both animals and humans, is common. Around 4 per cent of cats have it, as do 8 per cent of dogs.
This disease is easy to transfer through fecal matter, which is often present on your pets’ saliva because animals lick their anuses multiple times every day.
So if your dog licks your face and you swallow the parasite, you’re at risk.
Cryptosporidia or “Crypto”, another disease ingested through contaminated water or faeces from animals, has similar symptoms.
Leptospirosis, commonly known as Lepto, is a common zoonotic disease and is far more severe. Veterinarians are able to vaccinate pets for it (dogs and horses are particularly susceptible).
Lepto can spread to humans via the urine of an infected animal, which can remain infectious on soil and in water for weeks or months.
It can also enter the human body through the mucous membrane (eyes, nose, mouth), especially in situations where you have broken skin.
Treatable with antibiotics such as doxycycline and penicillin when administered early on, if left untreated Lepto can cause kidney and liver disease and meningitis in humans.
“Cat Scratch Fever”, scientifically known as Bartonella hensale, is present in around 40 per cent of cats at some point of their lives.
Transmitted to humans by a simple scratch (or bite), can cause swelling and infection of the skin and lymph nodes, and requires an immediate visit to a doctor.
There are some other bacteria, viruses, fungi, and parasites you can get from your pets, but you get the point by now. Zoonotic diseases are real, and some of them are scary.
However, here’s the good news. Zoonotic diseases aren’t that easy to catch.
Most veterinarians, in their professional opinions, will tell you to keep your pets’ tongues away from your faces. That’s wise advice, since it’s the most likely way to get infected.
Your pet licking any other part of your body is reasonably safe, however. Your skin is an extremely competent barrier between the nasties of the outside world and the vital things inside your body.
When animal saliva touches intact skin, especially if you’re healthy and have a good immune system, there will be very little absorption into your body.
It’s unlikely for it to be problematic, although elderly people and those who are immunocomprimised are at higher risk.
Capnocytophaga canimorsus (the main bacteria associated with dog bites) and Pasteurella multocida (also from bites and scratches) can cause severe problems in these two groups.
There is even some research to say that your pets’ saliva could actually be good for you.
Dog saliva contains a chemical called histatins, which speed up healing. Histatins promote new cell growth and help them to migrate.
London School of Medicine research has found that dog saliva creates nitric oxide when it hits the skin, which is an inhibitor of bacterial growth.
University of Florida research has even found that a protein in canine saliva called Nerve Growth Factor can heal a wound in up to half the usual time required.
Exposing broken skin to animal saliva still isn’t recommended by either doctors or veterinarians, however, so you can’t take this research too seriously.
On future note, there is some ongoing research into the effect of dog saliva on the human immune system, as dogs have greater bacterial diversity than humans.
Exposing yourself to diverse canine microbes, theoretically, could your immune system stronger. The University of Arizona is currently investigating this.