Thoughts for Shots

Setting the record

A lot of people have questions about vaccinations for puppies. When to give what shots to which dogs is often the focal point. Many people are surprised to learn that there isn’t really an ‘official shot schedule’, beyond the relatively standard consensus regarding the first 3-4 rounds of shots for puppies. But lately, it seems there has been an increase in concerns about the vaccinations themselves.

From time to time, we get requests for puppies that are vaccine free. These requests come from well-meaning individuals who intuitively feel nature is safer. Like us, they want what’s best for the puppies. And to them, it seems unreasonable that we will not accommodate such a request. Honestly, I understand the hesitance. It can seem unnatural to inject foreign substances into a tiny puppy. And there is no shortage of websites containing “information” on the internet that can lead one to misplace fear. Now, we could dig into the vast literature showing the safety of the shots. But from my experience, the misinformation taken in from incredulous websites has already primed people against it. On one such site, it claimed that recent research had shown that vaccinations for canine-parvo virus (CPV) did not work, and to my surprise, it even provided a citation. The reference was to a paper called Canine parvovirus vaccination and immunisation failures: Are we far from disease eradication?

The Devil in the Details: My Pet Peeve

Despite the ominous wording of “immunisation failure” in the title, the paper offers no support to the position presented on the website that references it. The paper was about failure in eradicating CPV. In the paper’s conclusion, the authors lamented:

“Despite intensive vaccination…CPV infection remains a leading cause of death from infectious disease amongst domestic dogs worldwide and at the moment we are far from disease eradication. Immunisation failures are uncommon and are mostly the result of interference from MDA in pups under the age of 16 weeks” (emphasis mine) (1)

But what do the authors mean when they say vaccination failure is “uncommon”? Let’s look at the data they used from 166 vet clinics, which looked at 1151 test confirmed CPV cases that occurred in the year of the study. (2)

First, It’s clear that younger puppies are more likely to get CPV than older puppies.

Age of the cases:

<6 months of age: 691 reports (60.1%)

6-12 months of age: 289 (25.2%)

12-18 months of age: 85 (7.4%)

18-24 months of age: 22 (1.9%)

>24 months of age: 67 (5.8%)

Secondly, it’s clear that unvaccinated puppies are far more likely to get CPV than vaccinated puppies.

Vaccination Status:

3.3% with a history of vaccination in the previous 12 months

17.0% had an incomplete primary vaccination course

58.3% that were unvaccinated

21.4% that had an unknown vaccination status

Conclusion

The incidence and mortality of CPV varies along many variables. In the study we looked at, 614 of the cases died. In the worst conditions, such as without treatment, survival rates as low as 9% have been observed. (3) With early detection, clinical treatment can vastly improve the survival rate (4), but treatment can cost several thousand dollars. Given all of this, there is simply no rational argument against CPV vaccination. However, while CPV is still a leading cause of death, the ethical argument is clear.

References

1. Decaro N, Buonavoglia C, Barrs VR. Canine parvovirus vaccination and immunisation failures: Are we far from disease eradication?. Vet Microbiol. 2020;247:108760. doi:10.1016/j.vetmic.2020.108760

2. Lechner, E. S., Crawford, P. C., Levy, J. K., Edinboro, C. H., Dubovi, E. J., & Caligiuri, R. (2010). Prevalence of protective antibody titers for canine distemper virus and canine parvovirus in dogs entering a Florida animal shelter, Journal of the American Veterinary Medical Association, 236(12), 1317-132

3. Mazzaferro EM. Update on canine parvoviral enteritis. Vet Clin North Am Small Anim Pract 2020;50(6):1307-1325.

4. Venn EC, Preisner K, Boscan PL, et al. Evaluation of an outpatient protocol in the treatment of canine parvoviral enteritis. J Vet Emerg Crit Care 2017;27(1):52-65