Dogs do not get a "stomach virus" flu like people do so, if your dog is having vomiting and/or diarrhea, there is some other reason. Your dog needs to see his/her Veterinarian.
Dogs do catch some viruses that are contagious to humans, and vice versa. Even though dogs can share illnesses with their owners, it is not possible for a dog to share his flu (or any other illness that causes an upst stomach) with you.
Mammals in most cases are susceptible to the same viruses.
In cats, the Feline Leukemia virus is a highly contagious to other cats who share food bowls and litter pans. Dog Leukemia is not contagious to other dogs. Feline Leukemia is caused by a virus. In dogs, Leukemia is a cancer of the blood. Like most other types of cancer, the causes of Leukemia are not well-understood, there aren't any measures to prevent Leukemia in your dog.
Contagious means that a disease can be passed from one person to another, like a cold. This is not. A person gets this by inhaling fungus spores.
Yes you are still contagious.
They are highly infections, not just to dogs, but to humans as well.
no
Yes
No. There are no cases of dogs having the HIV virus. That said, sex with animals (bestiality) is a serious crime in most countries round the world.
If a dog has a blister that has turned into a crusty sore on its stomach, a person should take the dog to the vet. Alternatively, it may be cleaned with peroxide with antibiotic ointment applied afterwards.
Bacterial pneumonia may occur in both dogs and cats. It is highly contagious between dogs but cats cannot catch it from a dog.
There are many reasons why your dog could have stomach swelling. Your dog could have a twisted stomach for example.