Summary of Kennel Club Breed Records: Pug 2020
A new research report, Summary of Kennel Club Breed Records: Pug 2020, has been produced by Cassandra Smith. The report utilises publicly available data offered by The Kennel Club to describe health and breeding-related statistics and information. The author’s previous reports on similar and other breeds have been well-accepted, with appropriate methodology and presentation.
This analysis includes KC-registered dogs with statistics presented separately for Pugs of Standard colour and Non-Standard (NBS) colours. Included is information on litter statistics, inbreeding values, caesareans and AI, breeding stock used, health schemes and genetic testing. The report is clear and speaks for itself. (see PDF of the full report attached); it was originally posted [CRUFFA]. Below are a few comments on/highlights from the material.
For those who wonder why the separation by colour: the designation of colour variations differ from breed to breed and across registries. Generally speaking, within the Pug breed, puppies (or litters of puppies) are registered by colour as either Standard (as described in the Pug Breed Standard) or Non-Standard (and other colour). Not unique to the Pug, colour classification is often based simply on historical choices in acceptable coat colours and markings, and are not automatically indications of a dog’s “purity” or lack thereof. However, the breeding community may be quite sensitive on this issue and feel there are differences across breeders and dogs beyond the colours. Relatively rarely, genetic mutations may produce certain colours or ‘dilutions’, generally randomly, however, there are instances where deleterious colours have been selected for. Of course, it can also happen that the occasional non-standard colour puppy might simply not be registered. Interestingly, but perhaps unrelatedly, the median number of puppies per litter was slightly higher in the NBS litters.
One area of particular interest in wider discussions on breed-health strategies, is the limited extent to which existing health programs have been embraced by breeders. Although the creation of such programs has been acclaimed (see https://www.pughealth.org.uk/pug-5-star-health-scheme/), the fact that they are clearly not being embraced in a way to impact the health of the breed is very disappointing. There is a caution, however, that this might have been impacted by the Covid-19 pandemic, so future reports will be needed. Although Standard Colour Pugs have access to both health schemes, for 88% of litters neither parent had health scheme results recorded. As for Respiratory Function Grading, “Table 12 shows the RFG testing results of each parent [Standard Colour litters] prior to the birth of the litter. 12.6% of litters had at least one tested parent, with sixteen litters (2.5%) meeting the current criteria for lowest risk of BOAS, as documented in the Breeding Advice on the Kennel Club website. Testing was less frequent for NBS litters.
Summary of Findings
See paper for further discussion and descriptions of calculations, e.g. for coefficients of inbreeding COIs:
638 litters/2576 puppies
Non-Breed Standard Colour
733 litters/3429 puppies
|Litter size (median)
|COI % (mean/median/highest)
|5.4/ 4.4/ 30.9
|3.7/ 2.7/ 21.4
|Litters with COI>25%
|Sire age at birth of pups (mean/ median/ minimum)
|3.9/ 2.2/ 0.65
|3.1/ 2.7/ 0.54
Of note: some high coefficients of inbreeding. Perhaps a better picture of the challenges of inbreeding in the pug, or any breed, would be to utilize the rapidly improving "genetic COI" DNA tests available. A robust genetic COI test drastically improves precision compared to pedigree-based COI. Regardless, a COI (pedigree based or not) of more than 12, 25, 30% is a cause for concern.
There is also a high proportion of young sires being used. It is generally recommended to wait until sires are at least 2 or 3 years of age, health tested, and so-far free from inherited conditions. Similarly, a considerable number of litters indicate that the dam was bred at a young age. In addition, the number of litters per sire indicates that there is overuse of certain popular sires, relative to general recommendations.
There are causes for concern here and much to inform evaluation of breeding within Pugs in the UK. The information should also be used by Pug clubs and breeders outside of the UK. These types of statistics – not simply the recording of the data – are crucial to monitor the breeding and breed population and to provide metrics for the uptake and possible impact of health testing programs. Ms. Smith is to be commended and thanked for her efforts.
As we have written in other blogs and our recent article on the Norwegian Lawsuit on Dog Breeds and Breeding against some breeds with extreme conformation (see additional resources) it is not enough to say health and longevity is important. Breeding practices, attitudes and specific decisions must be made with those goals prioritized.
- Summary of Kennel Club Breed Records: Pug 2020 – Cassie Smith. (links: to discussion on facebook and link to file and pdf - attached below)
- Blog: Is it "tough talk" or "open dialogue" - and why is it a challenge in the dog world?
- Blog: Linebreeding vs. Inbreeding – Let’s be perfectly clear
- Blog: The Big Picture - in the Dog World as a Whole and for your next Breeding Decision
- Norwegian Lawsuit on Dog Breeds and Breeding - The "First" But Not the Last?