In short, no. Dog cancer is not contagious to humans.
HOWEVER, there is a very rare form of dog cancer that is contagious between dogs. This sounds really weird, since there is no known human cancer that is contagious to other humans. But for our canine friends, it’s a different story.
It’s called Canine Transmissible Venereal Tumor, or CTVT for short. It’s been around for over 10,000 years. Even though it’s a cancer, it acts more like a human venereal disease, like herpes. CTVT is passed from one dog to another during mating or when a dog comes into contact with an affected dog through licking, biting, or sniffing the tumor area.
Canine Transmissible Venereal Tumor disease cannot be passed from dog to human. The only other animal species that has shown to contract CVTV from dogs is the fox.
Before you get too worried that your dog might have this kind of cancer, it is much more common in feral or wild dogs. Buster, your bulldog who lounges around the house all day snoring, is not likely to become afflicted anytime soon.