I have a guilty secret: I’m a sucker for pugs. As a veterinarian this is deeply irresponsible. It is unethical to in anyway endorse a breed with such terrible welfare issues (due to breathing). But this doesn’t alter the fact that my oxytocin levels shoot through the roof whenever I see a pug. And I’m not alone, which is why pugs and other flat-faced breeds are so popular.

New research tells us there’s a gene for ‘breathing difficulties’. This could be a great tool for predicting which dogs will raise the healthiest pups. If we can test the parents ahead of breeding, this could make for less distress in generations to come.

In this article we consider predictors of excessive panting such as:

  1. The gene for breathing difficulties
  2. The significance of narrow nostrils
  3. Reading a face and predicting problems
  4. A weighty matter
  5. Avoiding extremes

#1: The Gene for Breathing Difficulties

Now here’s a thing. Not all flat-faced dogs struggle in the way others do. So is bad breathing all about skull -shape?

Recent research says “No”, and that there is a gene for respiratory distress. Indeed, this gene codes for airway ‘edema’ or inflammation, which narrows down the airways in a similar (but different) way to asthma.

This research came about because of a condition, Upper Airway Syndrome (UAS), in Norwich Terriers. The latter are a breed with a sensible sized snout, so how is it they may experience breathing difficulties? This led researchers to investigate the Norwich Terrier’s genome and discover the gene mutation, ADAMTS3. This is potential game changer.

ADAMTS3 codes for UAS, and it’s been identified in some French and English Bulldogs, and Staffordshire Bull Terriers… but interestingly not in Pugs, Boxers, and Shih Tzus.

What does this mean for dog-kind? Well, it gives breeders a way to choose the parents of the next generation. If they select dogs that lack the ADAMTS3 mutation, then the pups stand a better chance of growing up with open airways.

#2: The Significance of Narrow Nostrils

Certain quirks of anatomy put a strain on the airways and cause the problem known as Brachycephalic Obstructive Airway Syndrome (BOAS). These include:

  • Narrow nostrils
  • A large tongue
  • A long soft palate
  • A very flat face
  • Large tonsils
  • A windpipe with a narrow diameter

Some of these quirks you can see (such as narrow nostrils) but others are inside the dog, such as their tonsils, soft palate, and narrow windpipe. However, data analysis now shows us that the narrowness of the dog’s nostrils is a good predictor of whether these other internal issues are present or not.

In practical terms, when choosing a puppy, look for the one with the widest nostrils, as that most likely to be blessed with an open airway.

Flat faced dogs, such as pugs, are at increased risk of breathing difficulties.

#3 Reading a Face to Predict Problems

If you want to get really scientific about things, there are specific measurements that can be taken, which predict the shape of breathing to come. For example, in English Bulldogs the NLR (neck: length ratio) is significant. Long story short, the bigger the girth of the neck compared to the length of the body, the more likely the dog is to struggle on a hot day.

  • Bulldogs : The neck: length ratio is significant
  • Pugs: Take note of the skull index (The ratio of skull width to skull length) along with the eye:width ration (how far apart the eyes are)
  • Bulldogs: The skull index is also important
  • French Bulldogs: This is also the neck: length ratio

[To learn more follow the link: Conformational risk factors of brachycephalic obstructive airway syndrome. ]

#4: A Weight Matter

Now here’s a thing, it turns out the biggest risk of all is obesity. Yep, carrying too much weight further narrows down those airways and is the biggest risk of all. So keep your fur-friend slim!

#5: Avoid Extremes

Part of the explanation behind the breathing difficulties of brachycephalics is their fore-shortened faces. Whilst the bony case (the skull) is reduced in size, the soft tissue contents (tongue, soft palate, and tonsils) are not. This is likened to trying to fit size 42 feet into size 36 shoes – they just don’t go.

So sage advice is to avoid extremes. Breeders should not breed from those dogs with the flattest faces, for the future welfare of the breed. And you can make a difference by actively seeking out dogs that have a nose ….perhaps a puggle…but there again, I may simply be biased!

References & Further Reading:

Breathing Problems in Pugs and Bulldogs may have a Genetic Component. The Smithsonian

Brachycephalic Obstructive Airway Syndrome. University of Cambridge

Brachycephalic Airway Syndrome in Dogs. VCA Hospitals.