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3 October 2022

By mixing up terms like ‘brachycephaly’ and ‘short-muzzled’, more than 48 breeds are affected by enforcement criteria drawn up on behalf of the Ministry of Agriculture, Nature and Food Quality.

The scientific articles on which the enforcement criteria are based deals with brachycephalic breeds. In general, the brachycephalic dog (short-skulled dog) is defined by the skull width being greater than 0.8 of the skull length. This with the exception of the 2015 Packer et al study [1] which introduced the CFR ( muzzle length/skull length) as a hypothesis (=assumption) for the severity of BOAS, but never proved it.

In the enforcement criteria page 4 however, it seems to give its own definition to ‘brachycephaal’ being “brachy = short and cephaal = nose”. The fact that ‘cephaal’ is Greek for skull apparently does not bother to link this definition to statements such as on page 10 of the enforcement criteria:

“The main risk factors for BOAS are: flat muzzle, thick neck and obesity. (ix) “

Given the reference (ix), the conclusion comes from the work of Liu et al 2017 [2]. However, in the work of Liu et al 2017 (2), this conclusion does not appear. On the contrary. The conclusion in Liu et al 2017 was:

“In conclusion, stenotic nostrils, BCS, and NGR were found to be valid, easily applicable predictors for BOAS (+).” –

Incidentally, this is only half true because these are only the external features for BOAS.
It appears that the ‘

stenotic/closed nostrils‘ in the conclusion of the Liu et al 2017 study on BOAS were replaced by ‘flat muzzle’ in the enforcement criteria without any explanation.

This is therefore all the more remarkable because the Liu et al 2017 study with Jane Ladlow was partly designed to refute Packer’s intuitive hypothesis of the CFR precisely.

By introducing the CFR as an enforcement criterion, more than 48 dog breeds are now affected by criteria that were basically designed to ban breeding of a few breeds with some serious problems. Therefore, judging from the numerous TV programmes and publications, these criteria are about these three breeds and 45 other breeds seem to be accepted as collateral damage or at least not seriously considered. This apart from the fact that the CFR as a criterion is flawed as clearly and scientifically proven by Ladlow.

The enforcement criteria are breed independent as well as incidence independent. In short, a CFR < 0.3 is only decisive to get a breeding ban imposed whatever breed it may be. The dataset S1 behind the BOS study by Packer et al 2015 [3] comprehensively shows the data of more than 700 dogs studied of which 236 are labelled as brachycephalic based on a CFR < 0.5. In addition to dogs from 30 breeds known to be brachycephalic, this includes breeds such as the Labrador Retriever, Shiba Inu, St Bernard, the Jack Russel Terrier and about 14 other breeds because they also have a CFR smaller than the 0.5 set by Packer as the limit for the occurrence of BOAS (brachycephalic obstructive airway syndrome).

However, this limit only says that BOAS (by definition?) does not occur in dogs with a CFR greater than 0.5. It says nothing about the dogs with a CFR lower than 0.5 other than that it can occur in these dogs.
By translating the term brachycephalic as short-muzzle and setting the resulting CFR at 0.5, the enforcement criteria can now affect at least 48 breeds, brachycephalic and mesocephalic of which many breeds many without BOAS and/or BOS.

To be continued.

[1] Impact of Facial Conformation on Canine Health: Brachycephalic Obstructive Airway Syndrome Rowena M. A. Packer, Anke Hendricks, Michael S. Tivers, Charlotte C. Burn 2015

[2] Conformational risk factors of brachycephalic obstructive airway syndrome (BOAS) in pugs, French bulldogs, and bulldogsNai-Chieh Liu, Eileen L. Troconis, Lajos Kalmar, David J. Price, Hattie E. Wright, Vicki J. Adams, David R. Sargan, and Jane F. Jane Ladlow

[3] Impact of Facial Conformation on Canine Health: Corneal Ulceration Rowena M. A. Packer, Anke Hendricks1, Charlotte C. Burn 2015

Dutch enforcement criteria for short-muzzled dogs (2019) affects more than 48 breeds

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