Canine distemper is often fatal. Because it attacks primarily young puppies who haven't been vaccinated, their chances of fighting the virus are slim. There's no cure for distemper, so infected dogs receive supportive care while their bodies try to fight the virus on their own. Even dogs who survive distemper will have long-term consequences to deal with.
The mildest form of distemper involves only gastrointestinal and respiratory symptoms. Common symptoms include intestinal bleeding, dehydration, coughing and sneezing, loss of appetite, vomiting and diarrhea, fever and discharge from the nose and eyes. These symptoms appear during the first and second stages of infection. Dogs who only experience symptoms in these stages have a better chance of recovering and might have milder long-term effects to deal with. Those can include things like scarring of the lungs, hardening of the nose and dry eye.
According to Elkhorn Plaza Veterinary Clinic, about 50 percent of dogs who develop canine distemper will die. That risk is higher on dogs who enter the third stage of distemper, which affects the central nervous system. Once the infection progresses this far, dogs will experience seizures, paralysis, stumbling and other neurological signs. Dogs who recover from this stage will have to deal with some serious long-term effects, which might include blindness, shaking or other involuntary movements, ongoing seizures and more.
Because there's no cure for distemper, different vets might choose to give different medication to help support the immune system or treat the symptoms that appear. The same is true long term. Dogs who end up with long-term effects such as seizures might require ongoing anti-seizure medication. Others might need eye drops to deal with dry eyes. This is determined on a case-by-case basis.
Technically, once a dog has had and recovered from distemper, he can't contract it again -- so he doesn't need annual shots to keep him protected. However, the distemper vaccine is usually not given alone, but as part of the DHPPV. This is a single shot that protects against four deadly diseases: distemper, hepatitis, parainfluenza and parvovirus. Because of this, your dog should receive his yearly shot even if he already suffered from distemper.