Prevalence of Health Conditions Across Breeds

Prevalence of Health Conditions Across Breeds

Wiles, B.M., Llewellyn-Zaidi, A.M., Evans, K. et al. Large-scale survey to estimate the prevalence of disorders for 192 Kennel Club registered breeds. Canine Genetics and Epidemiology 4, 8 (2017)

Link (open-access): https://doi.org/10.1186/s40575-017-0047-3

By: Noah Stetson

This study collected data from over 40,000 purebred Kennel Club-registered dogs and found that some health conditions were significantly more common in certain breeds compared to others. This study is one of the first attempts to compare prevalence of health problems between breeds in a systematic way (instead of just using anecdotes).

Background

This study collected data via an internet survey completed in 2014 by owners of 43,005 Kennel Club-registered dogs, making it one of the largest dog health surveys ever conducted. The goal of this study was to see which health conditions affect dogs the most, and to see how much this varies between breeds (if at all).

Data & Methods

Data were collected from owners of dogs registered with the Kennel Club (the largest dog breed registry in England) on November 1st, 2014. Owners were recruited for the study online. The survey asked about each dog’s demographics (like their Kennel Club registration number), whether the dog was used for breeding (and if so, whether their puppies were born with any health conditions), the dog’s behavior, and whether the dog had any health problems. Owners could fill out a survey for up to 5 dogs they owned. You can see the full survey the owners completed here. The researchers then compared the prevalence and types of health conditions owners reported and compared it by breed.

Results

Demographics:

• They collected data from 43,005 individual dogs, and 187 breeds (see Table 1)
• The median age of the dogs at time of the survey was 4.47 years
• About 87% (187/215) of the breeds recognized by the Kennel Club were represented in this study
• Male and female dogs were represented almost perfectly equally (50.88% were male)
• 53.53% of dogs in the study were spayed or neutered
• About ⅓ of dogs in the study were reported by their owner to have a health condition

Common Health Conditions Reported:

• The researchers found that the most common health issues that owners reported were related to the skin/ear/coat (36.20% of health issues), followed by health issues affecting the muscles/bones/joints (16.87% of health issues), then digestive issues (10.12% of health issues) (see Table 2)

The most common medical diagnosis for dogs in the survey was lipoma (a non-cancerous fatty tumor), followed by cysts, then hypersensitivity (allergic) skin disorder

Health Comparisons Between-Breeds:

• Among the breeds in the study that had a least 200 dogs represented, the top 5 breeds with the highest proportion of dogs with a health condition were Boxers, Bull Terriers, Cavalier King Charles Spaniels, English Bulldogs, and Rhodesian Ridgebacks, and the top 5 breeds with the lowest proportion of dogs with a health condition were Whippets, Border Collies, Lhasa Apsos, English Cocker Spaniels, and Border Terriers (see Table 4)
• This figure (here’s the color blind-friendly version) shows the prevalence of health conditions in the 41 most common breeds in the study. Boxes shaded in green (or white for color-blind friendly) have especially low prevalence in the breed, and boxes shaded in red (or black for color-blind friendly) have especially high prevalence in the breed.

Boxers had the greatest number of health conditions that were found to be especially common in their breed compared to other breeds, and Labrador Retrievers had the greatest number of health conditions that were found to be especially uncommon in their breed compared to other breeds.

Discussion

One thing that is really cool about this study is that the researchers were able to collect data from a very large group of dogs. Before the age of the internet, conducting “Big Data” studies like these would be pretty much impossible! As technology continues to improve and people become more and more connected, we may start to see more Big Data studies in the future, and this study could be an example for future research to improve off of.

The breed-related health results from this study may support some common anecdotal claims about certain breeds having a lot of health conditions compared to others. In this study, Bulldogs and Cavalier King Charles Spaniels had some of the highest rates of dogs reported to have a health condition, while Whippets and Parson Russell Terriers had some of the lowest rates of dogs reported to have a health condition.

Across breeds in the study as a whole, skin-related conditions were more common than any other health condition in this study. Health conditions that people may often think of as no big deal (like allergic skin disorder) could be really important for breeders to focus on because of how common they are and how much they can negatively affect a dog’s welfare.

About ⅓ dogs in the study were reported to have a health condition, but a limitation to this study is that the median age of the dogs in the survey was 4.47 years old, so there were probably dogs in this study that went on to have health issues later in life that they didn’t have at the time their owners took the survey. Many health conditions, like arthritis and many cancers, become more common as an individual ages. Therefore, this study is probably not a very good way to compare age-related diseases between dog breeds. Collecting more health data from older dogs would allow us to see a bigger picture.

Additionally, it’s possible that owners may have misreported their dog’s health issues. The wording in the survey for some conditions described them as being “serious or persistent” (e.g. “22. Have any of the dogs included in this survey ever suffered from a serious or persistent heart condition(s)?”), but other conditions did not use these terms (e.g. “10. Have any of the dogs included in this survey ever suffered from any growths, lumps or cancers?”). Owners may have changed which of their dog’s health conditions to report depending on the wording of the question. Also, different owners may classify what counts as “serious or persistent” differently, so some health conditions may have been left unreported.

Another limitation of this study is that it only looked at purebred, Kennel Club-registered dogs, so they couldn’t compare to mixed-breed dogs or to dogs that weren’t registered with the Kennel Club, like dogs in other countries. Some breeds may be significantly more or less healthy in outside countries or registries. There were also some Kennel Club-recognized breeds who had very few or no dogs that participated in this study.

Finally, the survey data used in this study were collected in 2014. Incidences of certain diseases may have increased or decreased since then, as breeding practices and knowledge about dog health and genetics have changed over time.

This large-scale dog health survey summarizes how the prevalence and type of health condition can vary significantly between breeds. This study can provide a framework to guide future “Big Data” studies on dog health to improve our knowledge on what health conditions are affecting dogs the most and how health varies between breeds.

This work by the Functional Dog Collaborative is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.