On the page “Genetic diversity” here on the website, I write about the need for crossbreeding for the Pug to maintain its vitality and health genetically. I also write that all purebred dogs are a result of inbreeding, which is actually an old and outdated breeding method. We need to preserve our breeds, and we can do that long-term by occasionally mating with another breed to bring in new genes. Windig and Doekes write that approximately 5% of all litters born during a period of 25 years must be the result of crossbreeding in order to maintain vitality in the offspring (Windig and Doekes 2018). When it comes to brachycephalic dogs, there are also major anatomical problems, which means that more frequent work with crossbreeding is needed to improve the anatomy.
Many people are interested in owning a genetically and anatomically healthy dog, but at the same time there are also many people who are afraid of crossbreeding. It becomes a bit of a dilemma that many demand healthy dogs but few dare to do what is necessary: cross another breed into their own breed. To de-dramatize this regarding the Pug and the Retro Pug, I here have created a gallery with photos of Pug crosses from the F1 generation, i.e. they have a 50% genetic share from Pugs and a 50% genetic share from another breed (F means “filial”). Virtually all F1s here in the gallery have the Parson Russell Terrier as a donor breed, some have the Jack Russell Terrier, and some have the Shiba. (The International Retro Pug Club, in which I am chair, allows the Parson Russell Terrier, long-legged Jack Russell Terrier, miniature pinscher, and Danish-Swedish farm dog as donor breeds.)
It can be added that the F1 and F2 generations have so-called “hybrid vigor”, which means that compared to purebred dogs, they have high vitality and fitness; they are healthier, it is easier for them to reproduce and to get stronger, healthier puppies (see e.g. Scott and Fuller 1965: 11; Sponenberg et al. 2017: 87f .; Beuchat 2014 ; Sommerfeld-Stur 2016: 197ff .; Malm 2013: 147).
The photos below come mostly from private owners and in some cases from breeders. They may not be used without the permission of the owners. Many thanks to all the owners who have given me the opportunity to publish these photos here!
F1 Pug x PRT/JRT (in Germany called “Rassmos”):
F1 Pug x Shiba from Meranda Sterk’s kennel:
Sources and further reading:
Beuchat, Carol. 2014. “The myth of hybrid vigor in dogs … is a myth”. The Institute of Canine Biology.
Malm, Sofia. 2013. “Släktskap och inavel: om avelsmetoder och strukturer”, in: Sofia Malm and Åsa Lindholm. Hundavel i teori och praktik. Svenska kennelklubben, 128–147.
Scott, John Paul and John L. Fuller. 1965. Genetics and the Social Behavior of the Dog: The classic study. Chicaco and London: The University of Chicago Press.
Sommerfeld-Stur, Irene. 2016. Rassehundezucht: Genetik für Züchter und Halter. Stuttgart: Müller Rüschlikon Verlag.
Sponenberg, Phillip, Alison Martin and Jeannette Beranger. 2017. Managing breeds for a secure future. Sheffield: 5m Publishing.
Windig, J. J. and H. P. Doekes. 2018. “Limits to genetic rescue by outcross in pedigree dogs”. Animal Breeding and Genetics 135, 238–248.