The trouble with fact-free and evidence-free journalism…

It must be the silly season judging by the article published recently in the Daily Mail which reports a variation on “look what 100 years of the show ring has done to pedigree dogs” which first appeared on Pedigree Dogs Exposed in 2008.  Jemima Harrison has blogged about the article here, in order to tell “the real story”.

Daily_Mail_100_years

Actually, there’s very little “journalism” in the Daily Mail article as they simply reproduce photographs from a blog written by someone with the pseudonym Mus Musculus.  As far as Dachshunds are concerned Mus Musculus shows two dogs from a century apart…

100_years_-_Dachs

Mus Musculus says: “The Dachshund used to have functional legs and necks that made sense for their size. Backs and necks have gotten longer, chest jutted forward and legs have shrunk to such proportions that there is barely any clearance between the chest and floor. The dachschund (sic) has the highest risk of any breed for intervertebral disc disease which can result in paralysis; they are also prone to achondroplastic related pathologies, PRA and problems with their legs.

What’s missing from all the articles/blogs are DATA and EVIDENCE.

By data, I mean the facts showing the prevalence of health conditions that can be attributed to “100 years of improvement”. By evidence, I mean the knowledge that 100 years of improvement has caused the health conditions; i.e. there is a cause and effect relationship between the two.

Let’s look at some facts for Dachshunds:

The Dachshund is a chondrodystrophic (dwarf) breed and therefore inherently prone to early calcification of the intervertebral discs compared with non-chondrodystrophic dogs. Dachshunds were chondrodystrophic 100 years ago. However, we have no prevalence data for IVDD on those early dogs.  We do know that Fitch Daglish wrote in the 1950s about IVDD and I have a copy of a Dachshund Club Handbook from 50 years ago describing the problem of back disease.

The data we have from the Dachshund Breed Council’s Dachs-Life 2012 Health Survey shows the following age profile of Dachshunds without IVDD, from a sample of nearly 1500 UK Dachshunds.  The survey also shows that there are significant differences in IVDD prevalence between the 6 coats/sizes of UK Dachshund.

Percent_Dachs_without_IVDD

This chart is very similar to the IVDD survival curves presented by Bergknut et al in their 2012 paper which analysed Swedish Agria Insurance Data on IVDD (Chart A = Mini Dachs, chart B = Standard Dachs):

Min_Dachs_IVDD_by_age Std_Dachs_IVDD_by_age

Let’s now look at evidence.  In July 2013 the Royal Veterinary College published a paper from research to quantify the relationship between relative thoracolumbar vertebral column length and IVDE risk in diverse breeds. A 14 month cross-sectional study of dogs entering a UK small animal referral hospital for diverse disorders including IVDE was carried out.  Dogs were measured on breed-defining morphometrics, including back length (BL) and height at the withers (HW). Of 700 dogs recruited from this referral population, measured and clinically examined, 79 were diagnosed with thoracolumbar IVDE following diagnostic imaging 6 surgery. The BL:HW ratio was positively associated with IVDE risk, indicating that relatively longer dogs were at increased risk, e.g. the probability of IVDE was 0.30 for Miniature Dachshunds when BL:HW ratio equalled 1.1, compared to 0.68 when BL:HW ratio equalled 1.5. Additionally, both being overweight and skeletally smaller significantly increased IVDE risk. 

In summary, longer dogs, overweight dogs and miniaturised dogs were more likely to have suffered disc herniations in the RVC research.

As with much research, the paper raises as many questions as it answers. For example, why are there differences between the different varieties of Dachshund; a result found in the Dachs-Life Survey.  We also need to understand why Dachshunds bred under the FCI Standard suffer similar levels of back disease to UK dogs, despite them having longer legs and shorter backs (Charts A and B above).

So, we have NO FACTS to suggest Dachshunds are more prone to IVDD now than 100 years ago and SOME EVIDENCE that longer Dachshunds are more prone to IVDD.  We also have facts that show longer-legged, shorter-bodied FCI-bred Dachshunds suffer similar levels of IVDD to UK dogs.  We also know that a Longhaired Dachshund or a Wirehaired Dachshund of any particular proportions will be at lower risk of IVDD than an identically proportioned Smooth-haired dog.

I want to say that I am not condoning exaggeration and the idea that Dachshunds should be “long, low and level” just winds me up.  We have to acknowledge that the Dachshund is inherently “exaggerated” as it is a chondrodystrophic breed.

  • Breeders should be selecting away from exaggerations in length of back and shortness of leg. 

  • Exhibitors and judges need to reflect on the evidence that longer dogs are more prone to back disease and remind themselves that our Breed Standard calls for a moderately long dog, with good ground clearance. 

So, what is the trouble with fact-free and evidence-free journalism?

Firstly, it is misleading. Secondly, it is only likely to alienate the very community that has any power to change things for the better.  And, thirdly, it offers absolutely no thought-through solutions, because the facts aren’t there and neither is the evidence.

Finally, let me share some Dachshund pictures (randomly chosen, of course) showing dogs from the 1900s to the 1930s.  Presumably the headline for these would have been “look what 20 years of the show ring has done”.

5_smooths

I’d be more likely to conclude that there has always been variation in conformation in the Dachshund and that, throughout the past 100 years, some people have pursued exaggeration which clearly is inconsistent with the requirements of the Breed Standard.

.

.

.

.

.

.

.

.

.

Advertisements

Comments are closed.

%d bloggers like this: