Wednesday, December 5, 2012

Parvovirus – An update

By Beth Davidow, DVM DACVECC
ACCES Medical Director

A week ago, we alerted referring veterinarians in the area to an uptick in the number of parvovirus cases we were seeing at ACCES’ two referral hospitals (Seattle and Renton). Word quickly spread to the greater community setting off an unexpected scare.

Parvovirus is a virus that causes vomiting and severe diarrhea. In addition, it can suppress the immune system and put animals at risk for secondary infections. It mainly affects puppies and can cause death if not treated appropriately. With treatment, which includes intravenous fluids, anti-nausea medication, antibiotics and plasma in severe cases, survival is 90%. Adults dogs can get the infection as well but often are less sick or may shed virus and not have clinical signs.

The virus is shed in stool and can live in the environment for weeks to months. It is extremely hardy and not killed by standard disinfectants – bleach is most effective. The virus can be passed from an animal shedding the virus, picked up on clothes, shoes, and other objects, and then carried to another animal.

Parvovirus is not a new infection. It is a virus we have known about for a long time and one of the first diseases for which we developed a vaccine for dogs. The vaccine is extremely effective when administered properly. Puppies need to receive vaccines every three to four weeks from eight weeks of age until they are over 16 weeks of age, again at one year and then every three years thereafter.

The difficulty with this disease is that puppies often get sick in the window after they have had one vaccine but not the full series. If puppies are in environments where the virus has been shed by asymptomatic carriers, they can pick up the virus. Health for the dog population relies on compliance by everyone – a concept known as “herd immunity”.

This year we have seen an uptick in the number of parvo cases. We see an average of 16 cases a year and have diagnosed 28 this year, eight in the last three weeks. The virus does ebb and flow so this may just be a high year. Cases have been from a number of locations and have been mostly young, incompletely vaccinated dogs. However, it is also possible that the move away from vaccines has led to less herd immunity and more shedding of virus. Speaking to other hospitals in the area, some are also seeing more cases but other clinics north of us are not.

Our recommendations are:
1)     VACCINATE – make sure your puppy gets the full SERIES of vaccines up to at least 16 weeks of year. Make sure the vaccine is boostered one year later and then every three years after that.
2)     Do not take incompletely vaccinated puppies to dog parks or other high traffic areas. Dog parks are great places to socialize but only after the full series of puppy shots have been given.
3)     If you have a dog with vomiting and diarrhea, have them seen promptly. Early diagnosis and proper treatment does lead to a good long term outcome.

If your dog is fully vaccinated, there is no reason to avoid the dog parks – let your dogs play if we have a sunny day.