Jessica Hekman, DVM, PhD, on "Lifetime Prevalence of Owner-Reported Medical Conditions"

We have a flipped episode this week with Sarah Stremming of Cog Dog Radio interviewing me. We're talking about the new paper out of the Dog Aging Project, "Lifetime Prevalence of Owner-Reported Medical Conditions in the 25 Most Common Dog Breeds in the Dog Aging Project Pack." There's been a lot of buzz on social media about this paper and we wanted to dig in to its findings. For those who saw our live Q&A about the paper, this interview covers very similar ground, although we go into some more detail. I'll include links to this study and others below, and if you want to ask questions about the paper, the Functional Breeding Facebook group is a great place to do it!

Forsyth, Kiersten K, et al. “Lifetime Prevalence of Owner-Reported Medical Conditions in the 25 Most Common Dog Breeds in the Dog Aging Project Pack.” Frontiers in Veterinary Science, vol. 10, 3 Nov. 2023.

• Original: https://doi.org/10.3389/fvets.2023.1140417
• FDC summary: https://functionalbreeding.org/common-conditions-seen-in-primary-care-visits/ 

Do purebreds live longer?

• Yordy, J, et al. “Body size, inbreeding, and lifespan in domestic dogs”. Conserv. Genet. 21 (2020): 137-148. - https://functionalbreeding.org/inbreeding-depression-and-lifespan/ - “For a given body size category, mixed breed dogs lived on average 1.2 years longer than purebred ones.”
• Urfer, Silvan R., et al. "Lifespan of companion dogs seen in three independent primary care veterinary clinics in the United States." Canine medicine and genetics 7 (2020): 1-14. - https://link.springer.com/article/10.1186/s40575-020-00086-8 - DAP authors before DAP started - “We did not find significant differences in lifespan between purebred and mixed breed dogs; however, breeds with larger effective population sizes and/or lower inbreeding coefficients had median survival times 3–6 months longer than breeds with smaller effective population sizes or higher inbreeding coefficients”
• Mata, Fernando, and Andreia Mata. "Investigating the relationship between inbreeding and life expectancy in dogs: mongrels live longer than pure breeds." PeerJ 11 (2023): e15718. - https://peerj.com/articles/15718/?f...gzQO4ualQE4De4iuO6RmqokNKNTRYdxORkaYEMBwDx_0I - VetCompass data - “mongrel dogs had the highest life expectancy, followed by cross-bred dogs with only one purebred ancestor and purebred dogs had the lowest life expectancy”

Increased inbreeding correlates to decreased lifespan

• Kraus C, et al. “How size and genetic diversity shape lifespan across breeds of purebred dogs”. GeroScience (2022). - https://functionalbreeding.org/size-genetic-diversity-lifespan/
• Bannasch, D., Famula, T., Donner, J. et al. The effect of inbreeding, body size and morphology on health in dog breeds. Canine Genet Epidemiol 8, 12 (2021). - https://functionalbreeding.org/the-effect-of-inbreeding-body-size-and-morphology-on-health-in-dog-breeds/

Are there specific disorders of concern that are more common in purebreds?

• Bellumori, Thomas P., et al. "Prevalence of inherited disorders among mixed-breed and purebred dogs: 27,254 cases (1995–2010)." Journal of the American Veterinary Medical Association 242.11 (2013): 1549-1555. - https://avmajournals.avma.org/view/journals/javma/242/11/javma.242.11.1549.xml - UC Davis, 24 heritable (genetic) disorders - “Purebred dogs were more likely to have 10 genetic disorders, including dilated cardiomyopathy, elbow dysplasia, cataracts, and hypothyroidism. Mixed-breed dogs had a greater probability of ruptured cranial cruciate ligament.”
• Donner, Jonas, et al. "Frequency and distribution of 152 genetic disease variants in over 100,000 mixed breed and purebred dogs." PLoS genetics 14.4 (2018): e1007361. - https://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1007361 - “Mixed breed dogs were more likely to carry a common recessive disease, whereas purebreds were more likely to be genetically affected with one, providing DNA-based evidence for hybrid vigor.” (i.e. it isn’t a problem if you don’t inbreed on it)