Dwarfed dogs: Ethical considerations for breeders

If I were giving this wrap-up as an oral presentation, I’d first ask for a show of hands from everybody who believed that deliberately producing puppies with a vastly increased probability of a painful genetic disorder that results in an early death is always wrong and the sign of a bad breeder. 

Then I’d ask if more hands would go up if that painful and often deadly genetic disorder could easily be prevented. 

Or maybe I’d ask it this way: Is it our responsibility to do absolutely everything we possibly can to reduce genetic disease?

If there were hands up from breeders involved in Corgi, Basset, Sussex, Dachshund, Skye, you fill in the rest of the list… those breeders have a lot of thinking to do.

When we breed dwarfed dogs, we are producing puppies that have a one hundred percent chance of getting spinal arthritis, and they’ll do so at an extremely premature age when compared to other breeds.

When we breed dwarfed dogs, we are producing puppies that have a risk of intensely painful disc disease and spinal cord injury that is, easily, an order of magnitude greater than the risk faced by non-dwarfed breeds. Dachshunds are up to 20% of all individuals experiencing catastrophic disc failure in the prime of their lives.

When we breed dwarfed dogs, we are selecting for traits that lead to a vastly higher rate of painful arthritis in the limbs, a vastly higher rate of painful growth plate injuries, a vastly higher rate of ligament damage that can render the dog unable to do his or her job. 

You think degenerative myelopathy is the bogey man? Disc disease is MUCH more common, incredibly painful, strikes in the prime of life, and is very likely to recur even if the owner can spend the four thousand dollars to get the sharp fragments of blown-out disc picked out of the dog’s rapidly swelling and dying spinal cord AND the dog is lucky enough to recover after surgery. 

The solution to ALL these issues is very simple, cheap, and easy to implement: Stop breeding dwarfed dogs. We can either end with this generation or we can begin to interbreed with Border Collies or something so we can push the breed up to normal leg length; either would be appropriate. Each breed club could decide which approach to take, with the goal of ending the production of defective dogs.

But we can’t possibly do that! I hear people saying. The price is too high! My dogs are perfectly healthy! The height has a vital function! These dogs were bred for a reason!

Well, then, PUT YOUR HANDS DOWN. Because you DON’T actually think that genetic health is the top priority. You DON’T think that deliberately producing at-risk dogs is wrong. 

If you breed dwarfed dogs — and I could have made this series about giant dogs, or brachycephalic dogs, or any number of the mutations we cultivate as part of breed type, but dwarfed dogs are very close to my heart right now and so, as usual, I’m trying to preach to myself — YOU MUST LOOK THIS IN THE FACE.

There are no scenarios under which the deliberate breeding of dwarfed dogs is without cost. It is a genetic malformation and it makes a whole bunch of the dog defective in function. 

What I strongly suspect that dwarfed-dog breeders ACTUALLY mean is that health is the top priority AFTER the maintenance or improvement of the breed itself. So do giant-breed breeders, and Boxer breeders (cancers) and Flatcoat breeders (even worse cancers) and so on. 

That approach is valid. But you need to admit to yourself that you are doing it, and you need to be consistent about implementing it. Don’t say that So and So who is breeding Snarfblat carriers is such a terrible person if you’re pumping out dogs who have a pretty decent chance of catastrophic spinal injury. Take out the log in your own eye before you look for the fleck in someone else’s, as a very wise book says. 

So how CAN we remain ethical breeders, responsible for each puppy’s entire life, under these circumstances? How can we fulfil our commitment to puppy owners?

I think that answer, too, is simple. We remain responsible for each puppy’s entire life. And we don’t throw puppy buyers under the bus.

Prospective owners MUST be told about the unique skeletal system that they are buying. They MUST walk away from your living room with enough information that they are making a decision with their eyes wide open. I think it’s entirely appropriate to also tell them that despite these limitations their dog will most likely live a very long, healthy, and happy life. But they should never think that nothing can happen. If they know the problems that are characteristic of dwarfism, they will be much more motivated to work to prevent the issues (a careful diet to prevent hip problems, supplementation for disc health, careful conditioning to exercise, avoiding the falls and concussive events that hurt growth plates, etc.) and much more prepared to respond to the issues when and if they occur. You want a puppy buyer who knows enough about disc disease that she suspects it quickly and gets the dog to the vet in time to prevent nerve death. You want a dog owner who knows enough about achondroplasia that they are not blindsided by diagnoses, so that they can become their dog’s best advocate when decisions about care, treatment, pain relief, euthanasia decisions, and eventual necropsy are demanded of them.

Carolyn asked if breeders were willing to chip all their dogs and take them back when something happens. To that I say OH MY HECK YES. In fact, that should be standard and expected of all breeders, now that chips are so much cheaper than they were even a few years ago. I used to have to ask the puppy buyers to do it and to add me as a secondary contact, back when chips were $75-$100 each, so having it come down to a tenth that much is absolutely wonderful. I am THRILLED that Kate is chipping all of Bronte’s puppies and will remain on the record as a contact forever. I look forward to being able to do the same.

And as for taking them back when catastrophe hits, I think that is one of the MOST IMPORTANT jobs a breeder can do. Owners often feel completely powerless to face the diagnosis, prognosis, and decision making that come with an end-of-life disease. I have told puppy owners that if they get to that point and just can’t handle it, the dog can come back to me. I’ll hold their hand and the dog’s paw and, either together or with the owner separated from the process if they desire, we’ll get through those last weeks or months. I think this is something that all breeders of all breeds should be willing to do, and when you’re producing puppies with specific weaknesses you should expect to do it at one point or another. Cradle to grave is the only right way to do it. 

I know I keep harping on this phrase, but OWN YOUR DECISIONS. Be willing to look very difficult facts in the face. Be willing to admit that you’re breeding dogs with some serious potential problems, and you’re doing so deliberately even though there are alternatives that will not cause the same problems. Be willing to lay out the honest facts in front of puppy buyers.

I don’t care if you do one health test or twelve. I don’t care if you produce one litter every three years or ten litters a year. Being an ethical breeder is about being willing to pick up a trembling old fat and incontinent dog that you sold twelve years ago, and keep him on your bed on a heating pad and feed him gruel for six weeks until you and the vet decide that it’s time for him to go to heaven. It’s about crying like a fool when he goes, and burying him next to his mother, and crying more when you think about her.  Being there for your dogs and your owners is the key.

Dwarfed dogs: What exactly is going on in there? Part 3: Other concerns

Because of the way in which achondroplasia/chondrodystrophy affects cartilage and other connective tissue throughout the dog, in addition to the issues that the dog WILL experience (vastly decreased growth, twisted bone, and spinal disc calcification), there are some problems that are a lot more common in dwarfed dogs.

Growth plate injuries (angular limb deformities): When the growth plate on one of the leg bones is injured (the cells are crushed by a blow or a very bad twist), even if there’s no fracture of the bone the growth plate can just shut down. The bone will end its growth cycle abruptly. However, the other leg bones will continue to grow. The most common place that this happens is in the radius/ulna (the lower bones of the front legs). The ulna stops growing while the radius continues, or the radius stops growing but the ulna continues. The bone that stopped growing keeps the growing one from pushing the leg down evenly. When the other bone continues to grow it buckles and bends outward, because the injured bone binds it to a certain length. This causes a major bow and twist to the entire leg.

Angular limb deformities (which we call “knuckling over” though it’s really not that) are much more common in dwarfed breeds than in other breeds. I’ve not seen a study that describes exactly why, but common sense would indicate that it’s a combination of thin, fragile growth plates that are already dysfunctional and the fact that the dwarfed breeds tend to be solid dogs who land heavily on front legs and are therefore are more likely to crush the growth plate cells. I can’t think of a single dwarfed dog that is not heavy-bodied; the early breeders didn’t shorten the legs of whippets. They shortened the legs of heavy hounds, shepherd-type herding dogs, the big terriers, etc., because the whole point of the short legs was to make dogs who could do the same sorts of jobs as the big dogs, but at a much slower speed or in a smaller area, or to accomodate handlers on foot rather than on horses.

So even as puppies, dwarfed dogs are heavy and sturdy of body. All it takes is for a six-week-old puppy to get her foot caught in the bars of the ex-pen and twist really hard getting it out, or one bad jump of a three-month-old off the porch steps (when the same jump a thousand times has done no damage), and the growth plate will give up the ghost. 

Unfortunately, angular limb deformities are not just unsightly; they’re quite painful for most dogs.

Joint issues: Achondroplasia in dogs is poorly understood. So there’s not a lot out there about exactly how each joint is affected by the dwarfism. But we do know certain things. Where bones come together, dwarfed dogs have shorter, wider, shallower joints than longer-legged dogs do. A perfect example of this is in the hips. The dwarfed hip has almost no neck on the femoral head. The femoral head is flattened and tends to form a “cap” rather than a smooth egg shape. And the acetabulum (the socket, which is part of the pelvis), in order to remain functioal with the femoral head, is also wider, shallower, and flattened. If I used the above three sentences to describe a longer-legged dog, I’m practically giving you the textbook definition of hip dysplasia. In a dwarfed dog, the hips are “bad.” The shoulder joint and the elbow joints are “bad.” Of course, that’s if you define “good” as “looks like a sighthound,” which is not what we have, but there’s no question that if a dwarfed hip was submitted as a longer-legged breed the diagnosis would be poor. If a dwarfed elbow was submitted for examination under a longer-legged breed’s name, that elbow would be seen as deformed. 

Ligament laxity: There’s definitely SOMETHING going on with achondroplastic ligaments. Humans with achondroplasia are known to have very lax ligaments compared to normal. Dog achondroplasia is NOT the human disorder, but I think the ligament issues may be analogous. You can see this most clearly in the front legs (again) in the wrists. Dog wrists are like marbles packed in a strong rubber tube–there are a bunch of round bones that don’t sit in balls and sockets but are held next to each other by strong ligaments. In most dogs, the marbles stay in a nice compact formation and can flex slightly and return to their former shape. In achondroplastic dogs, the strong rubber tube, it seems, is not so strong. It holds the marbles straight when the leg is just hanging there, but lets the marbles slump over to the side when weight is put on them. The “hush puppy” Basset hound front legs, where the feet end up going completely east-west when the dog stands up, represent the worst of this. 

Our boy Bramble (who is half dachshund and half achondroplastic Jack Russell Terrier) has one leg that is a perfect example of ligament failure. If you pick him up by the chest so his front legs dangle, the sections from the wrists to the toes are straight up and down. The toes point to the floor without much deviation. Put him down, and one wrist buckles rather dramatically. His wrist deviates inward toward his chest while his toes deviate outward and end up twisted to the outside of his body. The problem is not with his skeleton–the bones hang together normally. The problem is with his ligaments, which don’t keep the bones together when weight is put on the limb.

Watch Cardigans when they trot toward you. When they pick up the leg (taking weight off the wrist), the “crook” (which is the way we describe the wrist deviation) almost disappears. As the dog puts the leg down, the wrist deviation becomes much more apparent. 

Arthritis in the small bones: Lack of proper cartilage = the cartilage deteriorates and bone begins to rub against bone. The bones respond by growing spurs or bumpy bits. Bony changes in a joint are called arthritis; arthritis is painful because, well, bone isn’t supposed to grind against bone. Achondroplastic dogs get spinal arthritis very early, as we saw in the post about vertebral disc disease. They also tend to get arthritis in the bones of their wrists and feet. Several of my friends who are or were groomers absolutely refuse to accept Basset Hounds because in their experience Bassets ALWAYS bite when their nails are done. Picking up and squeezing the foot to get access to the nails is so painful to the dog that he sees no choice but to bite. I think their universally bad experiences are due to the fact that there are so many poorly bred Bassets with really terrible fronts, but the fact that dwarfed dogs get more arthritis is inescapable. 

Next up: What does all this mean to us as breeders?

Dwarfed dogs: What exactly is going on in there? Part 2: Not the legs

Yesterday I wrote about how the growth plates in Cardigan legs are dysfunctional and don’t grow a normal length of bone. Today I want to look at the second reason we care about cartilage as breeders:

Because the bad cartilage isn’t just in the legs.

Dogs with chondrodystrophy or achondroplasia have bad cartilage EVERYWHERE. It has abnormal cell distribution and formation all over the place, from the front of the dog to the back. 

Dogs function perfectly well with bizarre cartilage, as long as no growth plates are actually injured and the cartilage doesn’t fail and cause arthritis, just about everywhere. The major exception is in one of the other places where the body has very, very important connective tissue: the spine.

As almost everyone knows, between the individual bones of the dog’s spine there are “discs” of squishy stuff. What does that have to do with cartilage? That the squishy stuff, which is basically like those (awesome!) 80’s bubble gum flavors with a soft outside and liquid inside, is a bit like very young baby cartilage. It’s not actually cartilage yet; it’s a fibrous sack with liquid in the center. That nucleus of liquid is what makes the spine such an amazing shock absorber; the bones can compress without touching each other and can be stretched apart without injury.

As dogs age, and this means ALL dogs, not just ours, that young baby cartilage (fibers and liquid) begins to age and dry out and turn into real cartilage. Most dogs are experiencing some lack of flexibility in the discs by the time they’re ten or so. Real cartilage is not as soft and bouncy as the disc used to be, so the spine becomes less able to flex. The now-cartilagenous discs begin to degenerate as the dog gets older and older, and so the bones (the individual vertebrae) grow little bony spines to try to stabilize the disc material. This is spinal arthritis or spondylosis.

Spinal arthritis is VERY normal in elderly dogs of all breeds. In most of them it just makes them say “Oh my achin’ back” in the same way that we do (or will eventually) as we age.

In an unlucky few the bony spines grow into the spinal cord or begin to squeeze some of the big trunk nerves that come off the spinal cord. This can lead to progressive weakening, instability, and paralysis (which, by the way, can mimic DM and is one of the many reasons you NEVER definitively diagnose DM without a necropsy).

In a few breeds, there is a tendency toward a severe form of spondylosis that occurs early in life and in the neck vertebrae. This causes progressive weakness and a “wobbly” gait as the spinal nerves are squished, so owners and breeders call it Wobblers. Wobblers is unfortunately more common than any of us would like to see it in Dobermans and Danes, and as of yet nobody knows what makes it happen. Bony growths are usually associated with injury, so we’ve all wondered whether these were dogs who had their necks traumatized at some point (Dobies and Danes have very long necks for their bodies), or if there is some familial relationship, but you don’t see it reliably passed along and predicting it is impossible.

Thankfully, most breeds don’t see any disc problems or bony changes in the vertebrae until they are advanced in age.

But… and you know there has to be a but… there is one class of breeds that has major disc damage at a very early age. And yes, you guessed it. We’re part of it.

Remember how the growth plates of the long leg bones in achondroplastic dogs age much more quickly than they do in longer-legged dogs? The same thing happens in the discs between the spinal bones.

In achondroplastic dogs, the liquid center of the discs doesn’t stay liquid. By the time the dog is six months old (yes, SIX MONTHS) the liquid center is being replaced by cartilage. This isn’t quite the same thing as what happens with longer-legged dogs; the liquid doesn’t gradually dry out like happens as those dogs age. In dwarfed dogs the liquid is actively replaced by cartilage. By twelve months the replacement is dramatic. By the time the dog is three years old, each disc has only a fraction of the liquid that should be in its center, and the center has actually begun to calcify (become like bone). The fibrous outer layer of the disc now has to absorb all the strain on each vertebra, and it is beginning to degenerate too. 

Eventually, in a lot of dogs, the fibrous outer layer of the disc gives way, letting the inner material get out. The fibers are thinnest right below the spinal cord, so when the outer layer ruptures it usually does it there. This allows the inner material (which is by this point bony cartilage) to squirt out. It either squirts out upward, squishing the big bundle of nerves that is the spinal cord, or it squirts out up and to the side, squishing one or more of the big nerves that come down off the spine.

That’s why you can have a dog go down with a complete rear-end paralysis, or it can seem to go down worse on one side or the other. 

The final strike against achondroplastic discs is that when the discs rupture, it’s usually catastrophic. In other breeds when elderly dogs get disc problems it’s often that the fibrous outer layer tears slightly, allowing only a small bulge of inner disc into the spine. In dwarfed dogs the fibrous layer fails completely, allowing a great deal of actual disc material to the nerve bundles. 

What happens next (as though enough hasn’t already happened!) is that the disc material that’s exploded out of the ruined fibrous layer can directly harm or cut the nerves of the spine. If it doesn’t harm the nerves, it often cuts off the blood and oxygen supply to the nerves by blocking or tearing blood vessels. Even if it avoids those two disasters, the disc rupture is interpreted by the body as a major wound and the body rushes all sorts of vasoconstrictors (signals that tell blood vessels to stop letting blood through) to the area, causing damage to the nerves’ blood supply.  And even of NONE of those things happen, within hours the body will try to respond to the damage by causng a huge amount of swelling in the area. Again, spinal cord death all too often results. 

If the dog has a very small rip in the disc with only a bulge of inner tissue, it can recover with rest and meds. Unfortunately, that kind of tear is not very common in dwarfed breeds. If there is a catastrophically ruptured disc but there’s no swelling around the disc and the spinal cord is normal, there’s a decent chance that surgery (to the tune of about four grand) can restore function. The surgeon carefully removes the disc material and the nerves can recover. However, a different disc will often herniate later, especially if multiple discs are showing calcification. If the ruptured disc has already caused swelling of the spinal cord, even with surgery the dog has the odds against him or her ever recovering the ability to walk.

Disc rupture occurs in dwarfed breeds most often in their middle years, from age 3 to age 8 or so. It is intensely and horribly painful, at least until the spinal cord dies. It’s a true emergency, and in our breed non-surgical methods are rarely effective.

Dwarfed dogs: What exactly is going on in there?

Watching Bronte’s puppies has been nothing but pure joy for me. OK, well, pure joy plus obsessively bugging Kate for weight progress (what can I say; I’m a former Dane breeder who was trained by a NICU nurse–weights are what I wake up at night thinking about). But most of it has been just fabulous.

One of the things that I found EXTREMELY interesting is that the puppies were born with (proportionally) long legs, as long as the legs I saw on any Dane born in my kitchen. But, very quickly, as bodies filled out and lenghthened, as weights soared (sigh of relief on my part) the legs got bigger and thicker but, length-wise, stayed pretty much where they were when they were born. It’s very easy for me to see that by the time the puppies are eight weeks old, they’ll be nearly twice as long as they are high whereas my Danes were about as tall as they were long. 

So what is going on here? Why do Cardigans, along with so many other breeds, end up with such short legs?

The answer lies in a word we throw around a lot but often don’t understand–achondroplasia, or chondrodystrophy. Those are the words that are used to describe what happens in dwarfed dogs, but they’re rather distressingly poorly understood by most. 

Both words–achondroplasia and chondrodystrophy–basically mean “crappy cartilage” or “failure of cartilage.” In humans with dwarfism, achondroplasia is a much more exact word that labels a particular type of dwarfism associated with a particular gene. In dogs, the word is a descriptor rather than a diagnosis–we have no idea what gene or genes make dogs short-legged, and aside from the fact that we’re sure they have deformed cartilage with a bunch of bone problems there’s not a lot of information out there. 

So why is our unique conformation associated with cartilage? For two reasons. The first is that cartilage is where bone growth occurs.

If you want a complex description of what happens, look here. I’m going to try to make it a little easier to understand. 

Look at your arm from your shoulder to your elbow. That’s the humerus bone. It’s the same bone as goes from the center of your Cardi’s body (the “shoulder” joint actually points toward her nose) to her elbow. If you feel your own humerus (if you’re like me you have a healthy fat covering over the bone, but try) it’s pretty long and skinny and straight, with swellings at the shoulder end and the elbow end. If you felt a Lab or Great Dane humerus, it would feel the same way–long and thin, with swellings at both ends. If you feel the same bone in your Cardigan, hers will be mostly lumpy end and other lumpy end, with a tiny section in the middle. Your Cardi’s humerus will also be MUCH shorter than your Lab’s–the long-legged dogs have elbows roughly at the level of the bottom of their chests, while Cardigans’ humerus ends several inches above the bottom of the chest.

The difference between these two lies in how the growth plate works. 

In a normal dog, when it is a puppy, those lumpy ends of the bone have a layer of slippery cartilage that allows the joint to move freely, and then right above that slippery layer is a VERY active layer called the growth plate.

The growth plate has a bunch of round cells in it. As those cells get a little older, they begin dividing rapidly, almost frantically. The result is a whole ton of round cells. Meanwhile, behind this whole ton of round cells, the new baby cells are being born. Then that whole ton of cells move from being round to being veerrrrry long and stretched-out, with lots of little arms that reach out upward and downward. Then the cells die, but they leave their skeletons (veeerrry long and stretched) behind. Then more cells come and build calcium all around those stretched-out arms, making the skeleton of the former cell extremely strong, but still lace-like, with lots of tiny holes. Eventually little blood vessels come and grow all through the holes and laces, and then you have mature bone.

So, basically, the way bone grows is that it pushes from either end, building the long skinny bit in the middle. Eventually hormonal signals that say “I have a grown-up pee-pee, and I like girls!” or “I have a strange feeling that I might like boys” come along, and those hormones gradually shut down the growth plates and the growth of those bones is finished. 

What’s different in dwarfed breeds is that the growth plate is a big pile of FAIL. Instead of having a big thick layer of a ton of those round cells dividing like crazy, it has a thin layer of many fewer round cells. Instead of a steady march of cells from round to long and thin, some cells fail entirely and some go really tall. The lengthening cells turn to mature bone LONG before they are supposed to.

The result is that the bone does not form a long thin straight column; it forms a thick, twisted, short column. And then it shuts down entirely. 

In the next post, we’ll look at what ELSE can go wrong with our cartilage failure, and why this is important to us as breeders.