Parvovirus

• Parvovirus, or simply parvo, is a highly deadly and contagious canine disease. The virus spreads through contact with an infected puppy's feces and can lead to death in as little as 48 hours. The virus works by attacking the digestive tract and blocking the absorption of necessary nutrients. Symptoms that may indicate a dog has parvo include vomiting and diarrhea.
  
  

Rabies

• Rabies is perhaps the most well-known dog disease. The disease is transmitted through the saliva of an infected dog or other animal. Rabies affects the nervous system and causes irritability and increased aggression. This aggression typically leads to biting that can pass along the disease. Rabies typically takes 2 to 8 weeks before symptoms begin to show, which includes foaming at the mouth, fever, erratic behavior and slow eye reflexes. Once symptoms manifest, the disease is fatal.
  
  

Distemper

• According to the American Veterinary Medical Association, distemper is the number one disease associated with canine deaths worldwide. It is highly contagious and can be contracted through airborne viruses or contact with saliva or feces. The disease takes a toll on the nervous system, eventually leading to seizures, paralysis and death. Early signs of distemper include coughing, diarrhea, vomiting, nasal discharge and weight loss. The end result is death in 80 percent of puppies and 50 percent of grown dogs who contract the illness.
  
  

Canine Hepatitis

• Hepatitis is a potentially deadly illness for dogs. The virus can infiltrate a dog's immune system through either inhalation or ingestion. Once inside, the virus attacks a number of organs, including the liver, kidneys and eyes. Symptoms are variable, but include fever, colic, red eyes and internal bleeding. While some dogs recover after contracting the disease, a high percentage is overwhelmed by canine hepatitis and dies. In extreme cases, the disease can cause death in less than 24 hours.
  
  

Considerations

• It is important to note that all of these deadliest dog diseases can be avoided through vaccination. Because of the prevalence and danger of such diseases, it is recommended that all dog owners keep their animals up-to-date on vaccinations. If you do notice some of the symptoms mentioned in this article, it is imperative that you have your dog checked by an experienced veterinarian as quickly as possible.