9. Canine Hepatitis

While this contagious disease is spread through body secretions such as saliva, it can cause liver inflammation and even result in death. Luckily, most dogs are vaccinated for canine hepatitis these days, so it doesn’t happen very often. In fact, it’s part of the core vaccine provided to dogs as the immunity they get from their mothers wears off.

The most susceptible time when a dog can become infected is when they are a puppy, simply because, just like children, their immune system isn’t fully developed.

Symptoms of canine hepatitis include congestion, loss of appetite, enlarged tonsils, watery discharge from the eyes and nose, and even blindness.