Many people allow their dogs to lick them, often viewing it as a harmless sign of affection. However, vets are issuing an urgent warning. Dog saliva can carry dangerous bacteria that may cause severe illness in humans.

In 2019, an Ohio woman named Marie Trainer became gravely ill after her dog licked a small cut on her hand. She quickly developed symptoms, initially mistaken for the flu.

She was diagnosed with an infection caused by capnocytophaga canimorsus. This bacteria is commonly found in the mouths of healthy cats and dogs. If it enters the human bloodstream, it can trigger a life-threatening immune response. This can lead to blood clots and cut off circulation.

Sadly, Marie’s severe infection required the amputation of both her arms and legs to prevent the spread.

Vets emphasize that dogs are “overlooked spreaders” of zoonotic pathogens—diseases that pass from animals to humans.

Researchers at Penn State highlight that our close bond with dogs increases risk. Unlike farm animals, dogs often sleep in beds or lick faces. Bacteria like Salmonella, E. coli, and Campylobacter can be found in a dog’s mouth.

While healthy adults often recover, there is always a risk of gastrointestinal illness. Parasites such as giardia and roundworms can also be transmitted through licking. To protect your health, experts urge caution when interacting closely with your pets, especially if you have an open cut or a weakened immune system.