Humphrey's tracheostomy, or Why brachycephalic dogs are so sad

Humphrey is a Pug who consumed most of my Thursday-Sunday this past week on Soft Tissue Surgery.

Pugs are one of several breeds of dogs that are considered brachycephalic. "Brachy-" means "short" and "cephalic" refers to the head. Hence, brachycephalic dogs are "short-headed" or "short-faced" dogs, also referred to colloquially as smush-faced dogs.

One of the biggest problems that we've created by breeding dogs with such a smushed-in face is that brachycephalic dogs often have serious respiratory difficulties. They are often born with two anatomical problems:

1. Stenotic nares, or overly narrowed nostrils, which allow for only very limited airflow through the nose.

2. An elongated soft palate, which interferes with the flow of air at the back of the throat.

Both the stenotic nares and elongated soft palate create extra resistance to what should be the normal passage of air through the upper airways. Think of it like trying to drink a thick milkshake through a straw -- you have to suck really hard, but you can probably do it. Now think about trying to drink that same milkshake through a coffee straw, which has a much smaller diameter and thus creates much more resistance and makes you work a lot harder.

So these brachycephalic breeds generally start out at a disadvantage when they have these congenital abnormalities. But the most serious trouble comes when the stenotic nares and elongated soft palate are not corrected early on.

After months or years of trying to breathe through such narrowed airways, the constant resistance to air flow and the excessive negative pressure that is created each time the dog breathes can lead to something called laryngeal collapse.

The larynx ("voice box," in humans) is a structure formed of several different cartilages that sits at the back of the throat and connects the oral cavity to the trachea (windpipe). Air passes through the nose and/or mouth, through the larynx, down the trachea, and into the lungs.

But with enough extra resistance in the airways for a long enough period of time, the cartilages that comprise the larynx begin to weaken and break down. Think of it like how you can suck your cheeks way into your face if your mouth is closed.

And like bending a paperclip back and forth enough times, eventually the laryngeal cartilages collapse. When this happens, they fall into what used to be the open space in the larynx where air passed, and create an obstruction to air flow.

Now, brachycephalic dogs are not born with laryngeal collapse. It is a sequela to years of increased resistance to air flow, resulting from their stenotic nares and elongated soft palate. So if the nares and palate are surgically corrected early enough in life, the increased resistance to air flow disappears, and the larynx does not undergo the stress that might have caused it to collapse.

However, often by the time an owner or veterinarian realizes that a brachycephalic dog might benefit from surgery to correct the nares and palate, it has already been a long-standing problem such that there is already some degree of laryngeal collapse. For this reason, more and more vets are now recommending that brachycephalic breeds have their nares and palate corrected at the time of spay or neuter, or as soon after that age as possible.

Here enters Humphrey, our dear 3 year old Pug. Humphrey was born with stenotic nares and an elongated soft palate, but nobody saw a need to do anything about it. Humphrey was a happy, healthy little Pug until he was about 2 1/2 years old, at which time he began to have difficulty breathing.

Humphrey's mom took him to her regular vet, and eventually to a specialist, who performed the surgery to correct the nares and palate (which, by the way, is a fairly minor surgery to do). Unfortunately, at the time of surgery, the surgeon noted that Humphrey already had a moderate to severe degree of laryngeal collapse.

Many dogs, even those that already have some degree of laryngeal collapse, will benefit from surgery to correct their nares and palate. Humphrey wasn't one of them. He had progressively more and more respiratory difficulty over the next several months, until eventually he ended up at my vet school's teaching hospital, after his regular veterinarian felt there was nothing more to offer than euthanasia.

At presentation, Humphrey was able to breathe adequately in the exam room, but was depressed and underweight. His owner reported that Humphrey's breathing was the worst when he was relaxed or trying to sleep, presumably because then he lost some of his conscious control over the accessory muscles that were helping to keep his airway open. As a result, Humphrey couldn't sleep well because whenever he relaxed, he'd be unable to breathe, which gave him no energy to do anything during the day.

We performed a laryngeal exam on Humphrey, which involved lightly anesthetizing him just to the point where he would let us open his mouth and look at his larynx. The exam confirmed severe (almost total) laryngeal collapse.

The only known solution is to perform a permanent tracheostomy. This surgery involves making an incision through the skin on the throat, then removing a rectangular piece of the cartilage that makes up the trachea, and finally suturing the inner lining of the trachea directly to the skin. The tracheostomy allows air to flow directly into and out of the trachea, bypassing all of the upper airways, including Humphrey's problematic larynx.

It's not a minor surgery to undertake, and obviously it requires somewhat of a lifestyle adaptation -- the most important aspect of which is no swimming for the remainder of the patient's life!

Humphrey's surgery went well, and he recovered okay. His owner will have 4-6 weeks of hard work ahead of her, while she learns how to clean the mucus from around the tracheostomy site multiple times a day, and while Humphrey learns how to position his body so that he can breathe well through the tracheostomy. But eventually, he should be able to enjoy most activities he liked to do before surgery, and he should have a fairly normal lifespan.

I intended this to be more of an amusing post, detailing some of the more hilarious aspects of Humphrey's surgery and our instructional sessions with his owner in how to care for him after surgery -- and maybe I'll have a chance to write about some of that later -- but although there are some amusing aspects to this tale, it's at heart a tragic story of how we humans have manipulated some breeds of dogs to such extremes of anatomy that they suffer so that we can remark how "cute" or "unique" they are. Some examples:

- Most English bulldogs cannot give birth naturally and automatically need a C-section
- Shar Peis have such excessive skin folds that many of them suffer from lifelong skin infections
- Cocker Spaniels' long, fluffy ears are a perfect environment for trapping yeast and bacteria, leading in some cases to ear infections so severe that surgery is required
- Great Danes and St Bernards have been bred to such enormous proportions that their average lifespan is only 6-8 years
- Italian greyhounds, with their petite, delicate skeletons, can fracture a leg at the drop of a hat
- Chihuahuas with their adorable apple-shaped heads often suffer from open fontanelles (failure of the skull to close completely, leading to an opening where the brain is not protected) and hydrocephalus (water on the brain)
- Dachshunds have elongated backs and stubby legs, resulting in frequent back injuries and neurologic disease
- Brachycephalic breeds, including Pugs, English bulldogs, French bulldogs, Shar Peis, Boston terriers, Shih Tzus, Boxers, and even Persian cats often suffer from anatomical abnormalities such as those discussed above that can cause such severe respiratory trouble that quality of life is drastically reduced

It is a cause for serious thought when we humans, who have such affection for the animals in our lives, and consider them members of our families, at the same promote breeding practices that aim to further exaggerate the smush-face-edness of Pugs, the enormity of Danes, the long backs of Dachshunds, and the wrinkles of Shar Peis that leave these poor dogs with diseases that could cause years of suffering or shorten their lifespans.

(Aaaaaaaand.... off my soapbox!)