Dogs seem to lick anything but that doesn't seem to affect their health. I can't seem to reconcile this with normal hygienic theory.
Dogs have a higher saliva PH and helpful bacterias in their saliva that allow them to ingest bacterias that usually make humans sick, also most illnesses humans contract, animals do not.
Please note, humans can contract human illnesses from dog saliva, feces, urine, or blood.
The Benefits of Pet Saliva
The belief in the curative power of a dog’s lick dates back to ancient Egypt and has persisted through time. In modern France a medical saying translates to “A Dog’s Tongue is a doctor’s tongue.” Recent research has identified products in saliva that indeed aid in healing.
- Researchers in the Netherlands identified a chemical in pet saliva called histatins. Histatins speed wound healing by promoting the spread and migration of new skin cells.
- Dr. Nigel Benjamin of the London School of medicine has shown that when saliva contacts skin it creates nitric oxide. Nitric oxide inhibits bacterial growth and protects wounds from infection.
- Researchers at the University of Florida isolated a protein in saliva called Nerve Growth Factor that halves the time for wound healing.
Dog saliva is antibacterial. “Dog saliva does contain chemicals that are antibacterial and it’s very unlikely that saliva by itself would be a direct cause of infection,” says Harvey. “You often see dogs licking wounds and that is a cleansing action and an antibacterial action to promote the healing of a superficial wound.” Of course licking won’t cure all superficial infections in dogs, so veterinary visits are still often necessary.
Dog “kisses” may transfer bacteria to humans. Just because dog saliva has antibacterial properties does not mean that dog “kisses” are clean and humans should let their guard down. Dr. Edward R. Eisner, the first veterinarian to become a board-certified specialist in Veterinary Dentistry in Colorado, notes that it’s possible for bacteria to be transferred from pets to humans. One study published in Oral Biology in 2012 found that there can be a transmission of periodontopathic species of bacteria between dogs and their owners.