PARVO VIRUS AND THE IMPORTANCE OF VACCINATING


In the 1970s and 1980s, Parvo virus reared its ugly head and caused an epidemic that led to the death of hundreds if not thousands of dogs. It attacked dogs of all ages but was especially severe in puppies. Certain breeds also seem to be particularly sensitive to the virus, most notably Rotweillers and Doberman Pinchers. Because the virus causes the intestinal lining to die and slough, these dogs presented with severe bloody diarrhea, dehydration, and vomiting. As their bodies tried to fight the virus, they would often progress to electrolyte abnormalities, organ failure and, in the worst cases, death. Fortunately, there is a vaccine made for this virus. It is part of the DHPP vaccine (commonly called the distemper vaccine) and should be given monthly to all puppies until the age of 12-16 weeks and boosted every 3 years in adult dogs. However, as this case will show, all dogs react differently to vaccines and the degree of immunity relies on the response to the vaccine, the amount of exposure, in addition to the quality of the vaccine itself.
On September 24th, “Pink” presented for vomiting and diarrhea of one day duration. As a Rotweiller, the owner, who is also the breeder, was concerned about Parvo virus. A test was immediately run and sadly our fears were confirmed. Pink was positive for Parvo virus. Even more concerning was the fact that the breeder also owns her litter mate, Blau; and recently another of the puppies, Scarlet, had been returned after being adopted out and was living in the home. While both Blau and Pink had been vaccinated for Parvo virus every 4 weeks since the age of 8 weeks, Scarlet had only received her first DHPP vaccine before being adopted at 10 weeks of age. The adoptive owners had failed to continue her vaccinations after her initial series with the breeder. As of this point, only Pink was sick.
Pink was immediately isolated in our hospital and supportive measures were started. There is no medicine that can kill the virus, so we could only try to support Pink and prevent secondary infections from taking over her body. Pink was presented on a Wednesday and by Saturday, Blau and Scarlet were also sick and in isolation in the hospital.
The illness was tough to watch. The puppies had bloody diarrhea and vomiting for over a week. Finally the day came when, as we took Pink outside to an isolated area, she tried to play with some leaves that were falling! It was the start of her turnaround. Over the next several days, Pink continued to improve and after 11 days of hospitalization, she was discharged home. Blau took a bit longer, but she too eventually came around and was sent home. Scarlet, however, did not do well. With only one vaccine to stimulate her immune system given months ago, she had virtually no immunity to the virus. Her disease progressed. The lining of her intestines sloughed and her protein levels dropped. Despite multiple antibiotics, she became septic and her liver and kidneys began to shut down. When she developed pneumonia, the difficult decision to euthanize her was made 6 days after she was admitted. She was only 18 weeks old.
 So what’s the take home message? To successfully create an adequate immune response to any disease requires multiple factors with vaccines being only one. We don’t know where these puppies acquired the Parvo virus, but keeping young puppies away from areas with multiple dog exposure (dog parks, pet parades, etc.) is always a good precaution to take. However, vaccines made a difference in this case. While all the dogs got sick, only the dog with an incomplete vaccine history succumbed to the disease. And finally, vaccine companies are on your side. They want to keep pets healthy and they stand by their products. Merial, the company that made the Parvo vaccine used on these puppies, reimbursed the owner $3,500.00 to help cover the cost of treatment for her dogs because she did follow protocol for the two dogs that she owned.
Both Blau and Pink are now at home and doing great. The owner reports they are eating like crazy to gain back all the weight they lost. Her only complaint is that they both are getting too active and are bothering the adult dogs with all their play! The two adult dogs in the home never came down with any infections (both adult Rotweillers) presumably because they have a competent, adult immune system that adequately responded to their vaccines.