A Manmade Dog Illness

Obstructive airway disease in brachycephalic dogs.

[brachycephalic: from the Greek brakhys (short) + Latin cephalicus (head).]

English bulldogs, French bulldogs, pugs, Boston terriers, boxers, Pekingese, Lhasa apsos, shih tzus, affenpinschers, Japanese chins, Cavalier King Charles spaniels. These are many, but not quite all, of the breeds considered brachycephalic, meaning they have pushed-in faces. And people love them. Their impossibly adorable big eyes, flat noses, and heads that are often large in relation to the rest of their bodies are the very qualities that draw us to infants, and we want to hug these dogs up. Indeed, the French bulldog and the English bulldog are numbers 4 and 5, respectively, on the list of the most popular breeds in America.

More and more veterinarians are also coming out and saying that brachycephalic dogs are impossibly adorable — but they mean it literally. The dogs’ squished-in faces, especially those of the bulldog breeds, make it impossible for many of them to breathe normally, setting them up for discomfort and fatigue every waking moment of their lives. Imagine having to literally gasp for every single breath.

Your Dog editor-in-chief John Berg, DVM, is among the concerned veterinarians. “All of these breeds have been bred into a corner now,” he says. “Airway disease in brachycephalic dogs is manmade — a direct result of trying to breed dogs that have a certain facial appearance people find pleasing but that is potentially ruinous for a dog’s quality of life. The public often doesn’t realize that they can have severe, life-threatening breathing problems. Many owners don’t even realize that their own brachycephalic dog’s breathing isn’t normal,” he adds. “Because the snorting, raspy, wheezing sounds are constant and continuous, they think it’s the way it’s supposed to be. That’s not normal breathing. That’s compromised breathing.”

A surgeon at Tufts University’s Foster Hospital for Small Animals, Dr. Berg is on the front lines of tending to the problem — and is fairly up in arms about it. He reports that “we probably do two, three, even four operations a week to help brachycephalic dogs breathe better. It’s one of our most common operating room procedures.”

Tufts veterinary geneticist Jerold Bell, DVM, says that Dr. Berg is right to be upset about the issue. “The surgeons are the ones who have to deal with the worst cases,” Dr. Bell says, “and it’s not like an every-once-in-a-while kind of thing. It’s a big problem.”

Indeed, in an article Dr. Bell wrote for a peer-reviewed journal called CliniciansBrief.com, he identified Brachycephalic Obstructive Airway Disorder as the third most common genetically inherited disease of dogs, after Allergic Skin Disease and Canine Hip Dysplasia.

Not all severely affected dogs go on to have a surgery that allows them to breathe better and live a normal life. A study in England indicated that almost 17 percent of brachycephalic dogs die of respiratory failure at an average age of only 8.6 years — during what is supposed to be the prime of a dog’s life. The brachycephalic breeds most often affected are English bulldogs, French bulldogs, and pugs, Dr. Bell says. But dogs of other brachycephalic breeds can sometimes end up with very serious breathing problems, too.

Just what is brachycephalic obstructive airway syndrome?

Brachycephalic obstructive airway syndrome arises from a number of anatomical issues shared by affected breeds.

1. Overly long soft palate. The soft palate is essentially the back of the roof of the mouth, above the tongue. But in a dog with brachycephalic obstructive airway syndrome, it extends too far back into the throat and interferes with the flow of air into the larynx and trachea, or windpipe, Dr. Berg explains. “In some English bulldogs, it almost seems to fill the trachea completely, to the point that you wonder how they get any air at all.”

Dr. Bell says that just having the breathing problem can make palate issues even worse. Over time, he says, the constant “turbulence” in the back of the throat resulting from raspy breathing causes the soft palate to thicken as well as elongate more, blocking the airway to an even greater degree.

2. Narrow trachea. “The windpipe often just isn’t as wide as it’s supposed to be,” Dr. Berg says. Adds Dr. Bell, “this particular problem tends to be worst in bulldogs.”

3. Nostrils that are too small.

4. Too short a muzzle.

The importance of other anatomical abnormalities associated with brachycephalic osbtructive airway syndrome is debated among veterinary researchers, Dr. Berg says. One of the main debates centers on structures in the nasal cavity called turbinates — cartilaginous structures with a mucosal covering to warm and moisten air as it’s breathed. Some researchers say that because brachycephalic dogs have a smushed in nasal cavity, there’s too much volume of turbinates for the size of the cavity, making it difficult for air to flow through. For that reason, Dr. Berg says, “some veterinarians are for removing some of the turbanates. But not everybody’s sold on that. It’s more popular in Europe.”

More critical, and this is agreed on by the veterinary community at large, are secondary problems that can develop after a long period of time in a dog with brachycephalic airway syndrome because of the animal’s chronically having to work so hard to breathe. These include swelling in the airway, which, in effect, narrows it, making it harder still for air to get through. Sometimes the tonsils and other tissues inside the airway also become swollen. The larynx, or voice box (the part of the airway system that opens with each inspiration to let air in, then closes during expiration to prevent food or saliva from being able to enter the lungs), can actually fatigue to the point that it collapses as the dog grows older. “It won’t necessarily kill a dog, but it is very hard for us to treat,” says Dr. Berg. “It’s not an easy thing to correct surgically.”

Not every brachycephalic dog is affected, he points out. “Some function just fine, and many are not compromised. They can run around okay and might not even make much noise as they breathe. But for others, the disease is a progressive condition that often gets worse through life. A dog may be born seeming fine and doesn’t get brought in to see us until she’s a year or two, when the owner realizes something is wrong.”

It’s not just the noisy breathing or the inability to engage in physical activity without struggling for air that can tip people off. Sometimes, the airway disease is bad enough that the dog can’t fall asleep. When awake, she can hold her head in a position that allows her to get the most air possible. “Dogs are not stupid,” Dr. Berg says. “They’re smart. They know what they have to do. But once they’re asleep, they can’t maintain that head position, so they have a hard time even getting to sleep. They’re essentially awake much of the night, and that keeps the owner awake. Sometimes I’ve surgically corrected the airway disease more for the owner’s sake than the dog’s.”

Besides making it impossible to sleep, airway disease in brachycephalic dogs can cause gastrointestinal signs. “The dog has to move her chest sort of violently to breathe,” Dr. Berg says, “and that causes inflammation in the upper GI tract, which in turn leads to regurgitation and vomiting. Dogs with these obvious compromises are the ones who are most often brought in, but those who are simply loud breathers are sometimes brought in, too.”

Surgical solutions

Not all anatomical problems of brachycephalic dogs can be fixed. For instance, nothing can be done for a pet whose windpipe is not as wide as it’s supposed to be. “There really are two main surgical components for helping a brachycephalic dog,” Dr. Berg says.

Shortening the palate. The main surgical solution is to fix the soft palate by removing the back part of it and thereby shortening it to a normal length. “That dramatically helps most dogs,” the doctor says. “It’s a relatively simple surgery that takes about 20 minutes, if that.”

Widening the nostrils. “There are nip/tuck techniques that do the job,” Dr. Berg says. “It’s always a little bit subjective whether the nostrils are narrow enough to be contributing to the breathing problem. But if it seems to us by looking that they are quite narrow, we’ll open them up.”

“The standard is that the nostrils should be one-third the width of the nose,” Dr. Bell adds.

Widening the nostrils, like shortening the palate, is a minor surgery, Dr. Berg says. “And most brachycephalic dogs are pretty dramatically helped by those two little procedures.” But that doesn’t mean there’s nothing to it, he emphasizes.

First, there’s the cost of the operation itself, the cost of the anesthesia, and the standard post-op care. These together can amount to $3,000, Dr. Berg notes. On top of that, the dogs could be prone to post-surgical complications, like aspirating saliva or even food. All dogs who have had an operation run that risk during the aftermath of anesthesia. But because brachycephalic dogs may already have swelling way back in their throats and a narrowed trachea that an operation can’t fix, they could be at higher risk for a respiratory crisis if they regurgitate.

For that reason, Dr. Berg, says, “we always keep them in the ICU overnight after anesthesia,” which drives up the overall cost considerably because ICU is continuously staffed with doctors and veterinary nurses 24 hours a day. A single night in the ICU can run upwards of $500.

“We even have a special protocol for brachycephalic dogs who are going to undergo anesthesia,” Dr. Berg notes. “Before the operation, they are given medications for two weeks to reduce the chance that they’re going to regurgitate and potentially aspirate post-anesthesia. And we make owners sign a consent form with wording to the effect of, ‘I recognize that brachycephalic dogs have poor airways and therefore a greater risk for death from anesthesia than non-brachycephalic dogs.'”

What it all boils down to is that while the operations to help a brachycephalic dog breathe better are not major surgeries — and people are often glad they ordered them, seeing their dog breathe much more freely for the first time — the risk for dangerous breathing problems stemming from anesthesia is greatly increased immediately post-operatively in pets with brachycephalic faces.

A growing problem

Ironically, as much as veterinarians know that being brachycephalic is a big risk for a dog’s ability to breathe properly, and even live a normal life-span with quality of life that allows her to enjoy physical activity and tolerate the heat, the public is getting more and more besotted with the affected breeds. “Ten years ago bulldogs were ranked tenth and French bulldogs, 34th, in terms of popularity,” Dr. Bell says. “But if their meteoric rise continues, the French bulldog is primed to take over as the number one breed in the U.S. during the next several years. In the UK it will probably be next year.”

What’s going on? “The public thinks it’s cute that they snore and you can always hear them breathing so you know what room they’re in,” Dr. Bell says. “They don’t see the respiratory problems as an issue. As a matter of fact, an article written in Europe that came out a few years ago described the surprising responses that owners of bulldogs, French bulldogs, and pugs gave when it was explained to them by an interviewer that snoring and raspy breathing are signs of ill health. The owners said, ‘But I love that about them.’

“If your dog has hip dysplasia,” Dr. Bell says, “you recognize that it’s bad. The dog can’t walk right or walk without pain. But the public’s very visceral reaction to brachycephalic dogs’ very baby-like faces” is keeping them from reacting appropriately to their pets’ very real and debilitating health problem.

Looking ahead

So what can be done to stem the tide of more and more dogs being born who can’t breathe without great difficulty? It’s a matter of educating four different groups of people:

1. The public. Says Dr. Berg, “the biggest public service this article can do is to make people understand that yes, bulldogs and other brachycephalic dogs are great, cute, funny pets. But to be destined to be unable to breathe without suffering is a cruel fate. Air hunger is not pleasant. Yet no one is going to pass a law that bans highly brachycephalic dogs from being bred, so it’s up to people to stop demanding them. If they won’t buy them, the ones with the most pushed-in faces will stop being bred.” Dr. Bell agrees that “getting the public to understand that this is an issue” is a very important step.

2. Advertisers. In the UK, the British Veterinary Association has called on ad agencies to stop using brachycephalic dogs in television advertising, and Dr. Bell sees the media obsession with brachycephalics in America as well. “Yes, you still have your occasional golden retriever in TV ads,” he says, “but on television, more than 50 percent of the time, it’s a highly brachycephalic breed used in commercials. So the media are fomenting this moment of, ‘Wow, look how cute those dogs are.'” It’s not helping the situation. A soon-to-be-released Disney movie about a pug named “Patrick” will create greater demand for this cute but compromised breed.

3. Judges at Dog Shows. “Judges have to be educated to reward moderation and not the extremes in brachycephalism that we’re seeing,” Dr. Bell says.

4. Breeders. The Bulldog Club of America, which sets the breed standard, says that the face of the bulldog should be “very short,” and the nose “as short as possible.” But these terms “are probably not good wording for a breed standard,” Dr. Bell says, “because it means you’re having some of these extremes being called for” that lead to breathing problems.

“Probably, when the standard was written, muzzles of brachycephalic breeds weren’t as short as they are right now,” he says. “Over the decades, the muzzle length of the bulldog and other breeds has gotten shorter and shorter, based purely on what people desire,” so “as short as possible” has changed in meaning over time to something that’s detrimental to a dog’s health. “We need to go back to a more moderate phenotype [look]. There is enough genetic variation of head anatomy within the brachycephalic breeds that proper selection should improve their health.”

How can that be done? By educating breeders, Dr. Bell says. “Because of the public demand, more and more people are breeding brachycephalic dogs and paying less attention to genetic health. It’s become: ‘I’ve got a bulldog, you’ve got a bulldog, let’s breed them.’ That sacrifices attention to health.”

To stem the tide of indiscriminate breeding that leads to brachycephalic dogs who can’t breathe, the OFA (Orthopedic Foundation for Animals) maintains databases of genetic health assessments on individual dogs meant for breeding. If breeders select healthy dogs for breeding, they will produce healthier offspring. For example, the OFA already has a database for hypoplastic (narrow) trachea based on measurements on a chest radiograph. Dogs whose tracheas are too narrow for good breathing should not be used to produce offspring. “The OFA is now in the final stage of standardizing and introducing a stenotic nares (narrow nostril) measurement database,” Dr. Bell says.

“In Europe, mainly in Scandinavia and Germany,” Dr. Bell continues, “they’ve gone another route — a standardized walking test that’s kind of like a stress test. Dogs have to be walked for 1,000 meters (about 6/10 of a mile) in under 12 minutes at an ambient temperature between 59 and 68 degrees. The dog can pant during the test but must recover within 15 minutes to receive a passing grade.”

Such efforts will help select for the right dogs to be bred and for unhealthy dogs not to reproduce. There are also a lot of studies going on at the molecular level to learn how to identify the genetic markers for brachycephalic obstructive airway disease. Once they bear fruit, a simple blood test could tell which brachycephalic dogs are okay to breed and which will pass down the risk factors for respiratory illness.

“The findings at this point are preliminary,” Dr. Bell says. “Genes have been identified that alter facial structure, but these genes are gross genes present in all bulldogs, not the modifying genes pushing in one direction or another either for or against airway disease. But once modifying genes are identified, educated selection for breeding should greatly improve the situation.”

In the meantime, he says, “it’s getting breeders to go for moderate instead of the most extreme dogs. It’s getting the public to understand that this is an issue so that they look for health-conscious breeders that screen and select for healthy breeding dogs.”

Comments Dr. Bell, “the aim is to create breeding standards that keep brachycephalic dogs adorablebut healthy.”


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