spinal health - square vs rectangle? xrays?

Today I saw a sad post on Facebook from a pug owner about her beautiful show pug who had been diagnosed with SAD. Most long-time pug owners have probably dealt with a pug who had spinal issues at some point and time and they know first-hand how tough it is to watch the pug decline slowly or struggle to walk. Our companion pug in the 1990s, George Gershwin, slowly declined and we watched his back legs and hips gradually deteriorate until he could no longer walk. We had to use a sling to help him go potty outside ... from November until March. Yes, we should have put him down sooner but we just couldn't part with him and he was still alert in his mind and healthy in all other ways. It was heart-breaking. George was a neutered pet, not a show pug, from a back-yard-breeder (she also bred Emus who were on the other side of the fence, so we often joked that George was part Emu because he was so long). But, because of our experience with George, we add x-rays of the spine when completing health screening for our pugs we will breed, even though this is not a required test recommended by the Pug Dog Club of America, the parent club of AKC.  

We also do not necessarily always strive for a "shorter and shorter back" when selecting our pugs to be included in our breeding program. There are many theories in research addressing the correlation between the length of a pug's back and spinal diseases. Our personal experience has proven otherwise, yet we still do not want to discount the researchers' hypotheses. 

While the "short back" is increasingly popular in the show ring, and the breed standard does state "square" (versus rectangle), there are so many issues the pug breed deals with such as hemivertebrae, pug myelopathy, and cervical spinal arachnoid deverticulum (SAD). (Read more about the Pug's back health under “Hemivertebrae and other vertebral anomalies” and “Pug myelopathy (PM)”).

Some people suggest that it stands to reason that if we continue to breed pugs with shorter and shorter backs -- to an extreme -- there will be such a deviation from the 'normal spine' that it will be impossible to combat all of the spinal issues confronting the Pug breed. The theory is that excessive deviations from the "normal dog's" exterior (shorter and shorter backs) may mean that the breed will suffer further with spinal problems.

However, when I've questioned many pug breeders, and even a vet who specializes in digital imaging and health screening, this theory is quickly dispelled, favoring the assumption that the size of the vertebrae will become smaller to allow for the shorter back -- a miniature version of the spine so to speak.

So where is the truth? 

Obviously, only those pugs who have a healthy spine, with no vertebral or soft tissue defects, should be bred. And the only way to tell, just as with hips, is via CT scans or X-rays of the spine. So, perhaps all Pug breeders should consider adding spine to their health screening even if it is not required by the Pug Dog Club of America?

Then again, HV can still pop up even with clear spinal X-rays. Health tests aren't truly a 'guarantee' ... they are simply a helpful tool.  

Another example? We've seen other pug owner's pugs who are N/N die from PDE. Health tests, at least the ones currently available to us, can only take us so far. 

As to whether a longer or shorter back would provide for a healthier spine, we can only personally look to our own experience; we have had 4 "longer" (more rectangle than square) pugs over the years and two of them dealt with hip issues. 2 out of 20 pugs, and 2 out of 4 'longer' pugs. This is not research, but it's something worth considering. 

All breeders can agree to these goals, however:
Breeder goal: "No pug shall develop spinal arachnoid diverticula." 
Breeder goal: "No pug shall be challenged with hemivertebrae."
Breeder goal: "No pug shall develop Pug myelopathy."
(And we're not even addressing such concerns as seizures/PDE, eye problems in this discussion/blog entry).

So, when a pug does not receive the best score on a given health test should a breeder immediately pull them from the breeding program? The breeder has probably spent thousands and thousands of dollars pursuing the championship, hundreds more poured into health testing. Should they breeder just throw all this away, along with the hope and pride which was justifiably earned? Should a pug who is in the top 10 not be bred if it receives a low hip score? That's asking a lot of someone and sometimes the answer is not clearly evident.

Sometimes it's quite obvious, for example, when you can hear the breathing problems or see rear movement issues or deterioration. We have pulled 2 GORGEOUS champions from our breeding program because of health. We spayed one because of BOAS issues (elongated soft palate) and neutered another champion because of bad hips, plus he just kept growing too long. Yet, we have done this twice now .... both with AKC champions who were (are) GORGEOUS and amazing. One pug we neutered because of bad hips, plus he just kept growing too long. They were (are) both SO beautiful but, as the saying goes, "you can't breed a head" and health must always trump beauty when a choice has to be made between the two.

As if choosing which pugs to include in the breeding program was not difficult enough, Father Time has to step in and stir the pot. Often a pug does not develop certain health issues until it is older. Yet a breeder can't wait too long to breed because birthing becomes more difficult and older dogs have a less healthy uterine line. (Every heat hertz damages the uterine wall). Also, older dogs may be more prone to having sealed medical disorders. 

A breeder/exhibitor once confided in me that they were planning on using their dog in the breeding program even though it received the lowest possible rating for hips. Flunk with a capitol F.  The problem with hips is that you can't always tell (at least not in the first years of life) if a pug has bad hips just by looking at them. Only an x-ray shows what probably lies ahead for a pug.

So, is there any truth to the (verboten) theory that today's Pug standard of compact and "square" should have a looser interpretation and that a more 'rectangular' body shape would be more akin to a 'normal dog' thus affording less health concerns? 

Once again, we can only speak from experience and only 2 of our 'rectangle' pugs were the ones who suffered from hip issues.  

In the Netherlands, they are actively enforcing laws designed to prohibit the breeding of dogs with muzzles considered to be too short. The snout must be at least half the size of the skull in order to breed the dog. This affects at least 20 brachycephalic ANCIENT dog breeds! And the worst part of this is that they are NOT SOLVING BOAS breathing problems because, even with a 'snout', a dog can still have elongated soft palate issues and   they are requiring that pugs and other brachy breeds now have x-amount of a 'snout'. But, again, this is not going to solve the problems of elongated soft palate and other BOAS concerns. 

Labradors and other dogs with "snouts" can have elongated soft palate issues. Adding a snout will not solve the problem. Breeding ONLY healthier pugs will help address the problem. Eliminating an ancient breed from the face of the earth .... (hello! a breed that has survived from the time of Confucius?!) .... will not solve the problem, it will only eliminate an entire breed. 

Besides, pugs with long snouts?

Just ick.

Rectangle pugs? 

More ick.
I'm reminded of something my grandfather was quite fond of saying which is applicable to so many situations ..... "everything in moderation."

If the theory that indeed a 'longer' pug (more rectangle than square) is healthier ultimately, as some researchers propose, might we define a new shape somewhere in between square and rectangle? Perhaps we could name this shape Pugtacle.  

My guess is that the answer does not lie in any specific "shape" or snout measurements, but rather in the DNA sequence, mutation of genes, combination of gene mutations, environmental factors, damage to chromosomes, changes in the number of or structure of entire chromosomes, the structures that carry genes ....

.... The pug genome. ;)

In the meantime, Jeff and I will continue with health testing but also use common sense. If the pug sounds like a duck when breathing, well, it's time to schedule a neuter/spay. If the pug receives a moderate or below hip rating, or does not have a healthy spine, they are out of the breeding program. 

Perhaps we should say DNA stands for Do Not Assume instead of the molecules/chromosones and smaller extrachromosomal plasmid molecules that carry the genetic information in an organism. Do not assume a pug's hips are decent without an x-ray. Do not assume a pug's spine will be healthier in a rectangle-shape versus square pug. Do not assume you will eliminate breathing problems simply by requiring a longer snout. Do not assume a pug will be a healthy breather at age 4 just because it was a healthy breather at age 2. Do not assume that a pug with N/N haplotype with no copies of the NME-associated risk variants will not one day succumb to PDE - pug dog encephalitis - Necrotizing meningoencephalitis (NME), an inflammatory disease of the central nervous system that is usually progressive and fatal. Do not assume that because both parents are gorgeous, their offspring will be the next Best of Breed.  Do not assume you have all the answers. Ever. 

Part of DNA sequence - prototypification of complete genome of virus: