Dog Poop, Measles and Parvovirus
An Argument for Individual Contribution to Herd Immunity
Dr Pauline Chen wrote a compelling editorial linking dog poop to the measles outbreak in the US. Strange bedfellows, you think? Her point is that just as cleaning up after your dog is an act of personal commitment toward a healthier community, so is vaccinating your children against measles. Since the 1960s, we have depended upon ‘herd’ or community immunity to fend off this dangerous disease. By vaccinating 95% of our children, we have created herd immunity, which protected nearly 100%, including those too young, ill or compromised to be vaccinated themselves.
However, in recent years, quackery defeated decades of community immunity. A misplaced fear of autism has caused enough parents to stop vaccinating their children that the safety net has been compromised, resulting in 300 cases of measles this year alone.
So what does this have to do with dogs? Dog owners may be facing a similar break in herd immunity. Although parvovirus hasn’t been eradicated to the same extent as measles, ten years ago occurrences were primarily limited to unvaccinated dogs brought into shelters. Since the vast majority of owned dogs were vaccinated, herd immunity protected non-responders (those dogs genetically unable to respond to the vaccine), immune-compromised and very young dogs.
Over the past few years, parvovirus outbreaks at major dog shows have reported to sicken and even kill many dogs. Some of the dogs that got sick had been vaccinated but others had not. Initially dog breeders and owners thought this was a new form of parvovirus but testing hasn’t supported this hypothesis.
What is causing this spread of parvo into the owned-dog population? Some claim it is coming from Southern dogs shipped north for adoption. Although this is certainly a risk, it would be small and contained if 95% of the local dog population was vaccinated. So, my suspicion is that it has the same cause as measles—well-meaning caretakers who no longer fully vaccinate against this terrible disease, despite guidance from leading immunologists.
For the vast majority of dogs, the parvo vaccine is quite safe and effective. A single dose given after 16-20 weeks of age confers long-term, at least 5 to 7 years, if not lifetime protection. Unlike bacterial vaccines like rabies and leptospirosis, the parvo vaccine does not require a booster. In addition, very accurate antibody titers are available to confirm dogs have reacted adequately to the vaccine.
If a safe, effective, inexpensive vaccine is available, why is it not being used by every dog owner? I think there are a number of related answers:
- Avoiding Over-Vaccination. After years of being pushed into annual vaccines with multi-component vaccinations, many educated dog owners are trying to avoid over-vaccination.
- Loss of Trust in the Experts. Thirty years of unnecessary and possibly risky annual vaccination protocols by the veterinary community have caused many responsible dog owners to question the vaccine protocol advice they are getting from their vets.
- Lack of Understanding. Both owners and, frankly, many veterinarians do not fully understand how vaccinations work, when they should be given in puppyhood, and what antibody titers mean.
Since they no longer trust their vets, many owners are turning to the Internet for vaccine guidance. As with much health advice, recommendations from the Web range from expertise to quackery. Much of the latter recommends no vaccination or replacement of vaccines with homeopathic nosodes, which have not been shown to be effective against parvo. Yet we know that unvaccinated your dogs are at very high risk of becoming quite ill from parvo.
Trying to save a puppy or dog from parvo is an expensive, difficult battle. Losing a puppy or litter to parvo is heartbreaking. Save your dogs and yourself–vaccinate your puppies and dogs against this disease and follow up two weeks later with a titer to ensure immunity. Simple, easy, effective AND you will be acting as a responsible member of our dog community!
Resources
Chen, Pauline, M.D., Putting Us All at Risk for Measles, Med Page Today, June 26, 2014
Center for Disease Control, Measles Cases and Outbreaks
World Small Animal Veterinary Association Vaccination Guidelines
American Animal Hospital Association 2017 Canine Vaccine Guidelines