This post is also available in: Nederlands (Dutch)
31 oktober 2022
Actions against ‘short-muzzled’ dogs are beginning to take apocalyptic forms. In our view, this is due to the lack of nuance and the Dutch enforcement criteria. Nobody seems to have noticed yet that the limit of CFR < 0.5 (muzzle length/skull length) incorporated in the enforcement criteria affects a total of at least 30 brachycephalic breeds as well as 18 mesocephalic(!) breeds. Anyone who has bothered to open the data table S1 behind the Packer et al 2015 study regarding BOS will discover that numerous dogs from at least 18 mesocephalic breeds like the Labrador Retriever, St Bernard as well as the Jack Russel Terrier have a CFR that does not reach 0.5. So even dogs from these breeds with (by definition already!) an incidence of BOAS of 0 are now affected in the Netherlands by a breeding ban based on nose length.
This is despite the fact that in Packer and O’Neill’s encyclopaedic work 2021 (Health and Welfare of Brachycephalic (Flat Faced) Companion Animals) in which dozens of articles have been published concerning brachycephalic breeds, the CFR can only be found in two articles. Namely in chapter 9 which discusses the Dutch enforcement criteria with the CFR and adds that many in the Netherlands associate the CFR with a ban on breeding of purebred dogs in general. The second article in which the CFR occurs is found in chapter 10 in which by the authors rejected the hypothesis from the 2015 RVC BOAS study regarding the CFR. Furthermore, in more than 400 pages, the CFR did not recur which in itself is significant. With the electronic version, it is easy to extract the discussed breeds from this encyclopaedia. If you look at breeds, you will find that the science concerning BOAS and BOS is strongly concentrated around three breeds that are mentioned between 300 and 400 times each. Outside the middle category of a few Brachycephalic breeds, we come to the category of the Brussels Griffon and the Affenpinscher which are mentioned 9 and 3 times each in this encyclopaedia and then mostly in Chapter 10 to refute the relationship between the CFR and BOAS.
In the study mentioned below by Professor Richard Gill (mathematical statistician Leiden University) who reviewed the studies of Van Hagen 2019 (enforcement criteria for short muzzled dogs), BOAS study RVC in London 2015 and the Cambridge BOAS study 2017 on statistical principles. This shows that the CFR is not significant for profiling on BOAS and that these studies show nothing else. Presence of BOAS should be considered on a breed basis and often has different causes per breed as well. This is also what is clearly stated in the last two studies.
Question is why then did van Hagen place such heavy reliance on the CFR as they state as a “This ratio proves a good gauge for measuring the severity of BOAS. ” (page 13) even breed-independent and incidence-independent while the opposite has been scientifically proven?
Edwin Meyer Viol
Relationship between incidence of breathing obstruction and degree of muzzle shortness in pedigree dogs
Professor em. Richard D. Gill
19 September 2022
There has been much concern about health issues associated with the breeding of short-muzzled pedigree dogs. The Dutch government commissioned a scientific report “Fokken met Kortsnuitige Honden”(Breeding of short muzzled dogs), van Hagen (2019), and based on it rather stringent legislation, restricting breeding primarily on the basis of a single simple measurement of brachycephaly, the CFR: cranial-facial ratio. Van Hagen’s work is a literature study and it draws heavily on statistical results obtained in three publications: Njikam (2009), Packer et al. (2015), and Liu et al. (2017). In this paper I discuss some serious shortcomings of those studies and in particular show that Packer et al. have drawn unwarranted conclusions from their study. In fact, new analyses using their data leads to an entirely different conclusion