Dog saliva is antiseptic. Dog saliva was once believed to be antiseptic, and some people still believe it has healing properties. Though it can kill some bacteria, dog saliva contains its own exotic bacteria that can cause serious infections, especially in people whose immune systems are weak.
Back before modern medicines to disinfect, heal wounds and rid us of bacteria, oddly enough dogs did just fine by nursing their injuries to health with the use of their tongue.
People have known for many years now, that dogs always lick their wounds when they get injured. Now researchers are even stating something stranger. Their research has showed the dogs' licking can even prove to be something good for humans as well.
This may sound completely crazy even though having your dog licking your cuts and scratches can be unappealing. The fact is that research shows that dog saliva that comes directly from your dogs mouth can contain mild bacteria effect when placed in an open wound.
Speaking Of Bacteria...
Have you ever wondered if a dog can catch the human cold? Many people do. You may have noticed that your dog has probably never gotten sick when you and your other family members were experiencing a heavy case of the flu or a nagging cold, and the germs are saturated throughout the household.
If this is the case, then why didn't your dog get sick? The answer goes back to the properties contained in your dog's saliva. Everything that a dog ingests into his system will come through his nose and his mouth. And because of the antibacterial effect that his saliva has on incoming foreign bodies, these germs are literally wiped away before they can enter into his system. In addition, it is extremely rare for the same viruses to be passed from one species to another.
The only exception to this rule is when a person is experiencing an extremely damaged immune system. Viruses such as HIV and cancer patients are such examples. It is these people that may be prone to possibly catching a virus or other type of sickness from an animal. But remember, this is extremely rare and there is no need to worry unless you are categorized in the above weakened immune system scenario.