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Health & Genetics

What is Degenerative Myelopathy?

Degenerative Myelopathy is a progressive degenerative disease of the central nervous system that typically affects older dogs, usually showing up between the ages of 8-11 though for some it can be even later on.  Similar to some forms of the human disease ALS (Lou Gehrig’s disease), DM causes the white matter within the spinal cord to break down or degenerate.  This white matter contains the fibers that carry messages from the brain.  Without this input from the brain, over time they lose the ability to use their back end including eventual incontinence as well as front limb weakness and even difficulty swallowing.  A diagnostic workup may include bloodwork, MRI, spinal fluid analysis and the DNA test for the mutated gene which can help differentiate between DM and other issues such as disc disease, injury or severe arthritis.

Some early signs that owners may notice:

·         Hind paws knuckle or “roll” especially when the dog is turning. 

·         The hair on top of the back feet is worn or stained from scuffing the ground and often the center two nails are worn down.

·         The dog may be slow getting up from a down or even struggle to do so.

·         They easily lose their balance if accidentally bumped by people or other household dogs.

·         They may seem to sway or wobble when standing still.  Often people notice this when the dog is standing to eat their meals.

What can an owner do after diagnosis?

A diagnosis of Degenerative Myelopathy can be devastating news for an owner to hear.  One good thing about this disease is that it is not painful.  The other good news about this disease is that there have been many advancements in understanding how to manage the disease.  We cannot make the disease go away but what we can do, in most cases, is to try and slow down the progression of symptoms.  Mobility is the key. Mobility is best maintained by minimizing muscle loss and loss of strength for as long as possible.  It is also very helpful to work on maintaining core strength in these dogs.   

The first thing that is highly recommended is to seek out a trained rehabilitation specialist in your area.  The ideal is to get into a program as soon as there are any visible signs and/or a diagnosis is made.  With a progressive disease such as this, any ground lost cannot be regained so the best outcome will come from being proactive.  A rehab professional can offer such things as hydrotherapy with an underwater treadmill, structured therapeutic exercise as well as helping you with a plan at home and assessing when the dog is progressing so the game plan can evolve as things change.

Probably the best exercise you can do for a DM dog is walking.  Slow, controlled, on leash walking is a great, simple, low impact exercise that helps the dog exercise all 4 quadrants and work on core strength.  Now, by walking I mean on leash, very slow and without stopping every 5 seconds to sniff!  Treat it like you and the dog are walking on a treadmill by picking a point in the not too far distance and walking to it.  I know this is not always an easy task with an AWS so you may even need to do this in the house, up and down the hall, where distractions are minimal.  A short 5-10 minutes of walking a couple of times a day is fine.  If the dog is scuffing its feet then you may want to consider getting some booties to protect the tops of the feet.  I will also add that it is still very important for your dog to get outside, run, play, chase and do all the things they love as long as they are not in danger of hurting themselves.

Some other exercises you can do include weight shifting which means very gently rocking the dog back and forth while in a standing position so their weight goes from one side to the other.  This exercise is very good for core strengthening.  Be sure to be gentle and not knock your dog over!

Using a cookie to lure the dog from a sit to a stand is also a great exercise for both hind end strengthening as well as core work.  Be sure the dog is sitting nice and square when you start which may mean having the dog against a wall or in a corner.  Also watch to be sure the dog is using the hind limbs to get into the stand and not walking into it with the front.  Think of these as doggy squats!

Walking over cavaletti or ground poles is a great way to help maintain hind end awareness.  You can buy a pre-made set online or you can use things you have around the house.  Any type of handle, pvc poles, pieces of 2x4 are all things that can be used.  The height will be determined by how well your dog is able to maneuver them but initially you could start at 6-8” and your dog’s approximate height at the shoulders apart. 

A good rehab specialist will be able to guide you through these sorts of exercises and show you how to do them properly at home.  They will also help you to know when and how to either increase or decrease the difficulty based on each individual dog’s needs.  It is important to start a program as soon as your dog is diagnosed.  At rehab you will also have access to a modality that is showing some very positive benefits for dogs with DM.  Laser light therapy or photo biomodulation is not new.  It has been widely used in humans and horses for many years with canine use becoming more widespread in the past 10 or so years.  The laser uses light waves to reduce inflammation, increase blood flow and promote healing so it makes sense that it would be helpful for DM dogs.  The results for extending the mobility of these dogs are really quite amazing.

You can read more about the laser therapy study at this link:  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7187977/

Inevitably there will come a time when the dog will need some assistance to get around.  There are a number of options available to fit a wide range of budgets.  A harness or support sling can be a great help when the dog needs assistance getting up onto their feet or up and down stairs.  As symptoms progress and mobility becomes more difficult a wheelchair can be an excellent option for these dogs.  With a thoughtful and positive introduction most dogs will welcome the freedom that a set of wheels can bring them.  An AWS can happily chase balls and birds in its wheelchair!  Wheels can range from custom made, refurbished or even rentals, depending on individual circumstances.  It is best to start getting the dog used to them with lots of treats and praise before they truly need them.

Where does DM come from?

Degenerative Myelopathy is an inherited condition caused by a mutated gene. Let’s take a moment to have a little genetics review.  If a dog has 2 copies of this mutated gene, then they are at a high risk to develop the disease.  It is an autosomal recessive trait, which means a dog must inherit one copy of the disease gene from each parent.  The good news is that there is a test available for breeding stock.  There are 3 possible test results a dog could come back with.  If a dog has 0 copies of the gene then they are considered clear, this dog will not develop the disease or produce it.  If a dog has 1 copy of the gene, they are considered a carrier, this dog will not develop the disease but could produce it if bred to another dog that is a carrier.  If a dog has 2 copies of the gene then, as mentioned above, this dog is at risk to develop the disease and is also a carrier.  For breeding purposes as long as at least 1 parent is clear (has 0 copies of the gene) then none of the puppies can have 2 copies of the gene.  The goal is to try to avoid producing the disease not to remove it from the gene pool.  In other words, there is no reason not to breed a dog who has 1 or even 2 copies of the gene as long as the other parent is clear.  For those researching the breed before committing to a puppy, it is important to remember that there is no health benefit to seeking out a litter based solely on having 2 clear parents.  As our earlier quick genetics lesson showed, an otherwise well qualified breeding dog should not be ruled out because it has a copy or copies of this gene as long as one parent is clear.  There are many pieces that make up the puzzle that is a good breeding and this disease is just one of them.   

General Health Information