No. Cold and flu viruses are species-specific. “The common cold virus that affects humans is specific to humans,” explains Dr. Shelley Rankin at the University of Pennsylvania School of Veterinary Medicine, and “different animal species have different strains of influenza virus that affect them.”
If the cause of your pet’s diarrhea is Salmonella or Campylobacter, you can become infected if you have contact with the feces and then don’t wash your hands before touching your mouth or before handling food, says Dr. Rankin. However, reptiles (such as turtles and snakes), baby chicks and ducklings, as well as “pocket pets” (hamsters and mice), present a much greater Salmonella risk.
No. “It’s just as mucky or more mucky than human saliva,” says Dr. Rankin. Though most organisms in your dog’s mouth are not harmful, cases of bacterial transmission to people have been reported, so it’s not a good idea to let a dog lick your mouth, especially if you are immune-compromised. Also, be careful not to get pet saliva in an open wound.
Even if a pet is not sick, it may still harbor organisms that can infect humans. The bacteria that cause cat scratch disease, for example, can be passed from an infected cat with no signs of illness through a bite or scratch. Leptosporosis, a less common but more serious bacterial disease, can be passed from dog urine into human mucous membranes. It’s also possible to get ringworm, a fungal disease (not a worm) if you have contact with the skin of an infected dog or cat. And toxoplasmosis, a parasitic disease, can be transmitted from cats through feces.
You’re far more likely to get sick from another person than from your dog or cat. But you should still take precautions with your pets, especially if you have a weakened immune system or are otherwise at high risk (frail elderly people, pregnant women and young children). Always wash your hands after handling pets or cleaning up after them, get pets vaccinated and dewormed, control fleas, and take pets to the vet for regular checkups. Stay away from wild animals and strays. If a pet bites or scratches you, wash the wound and watch for signs of infection.