Degenerative Myelopathy

19th Nov, 2019

Written by Dr Mirjam van der Wel

Your healthy, happy dog is running around, happy as can be, when suddenly one of their legs gives in. Or perhaps you’ve noticed them struggling to get onto the couch or into the car. Maybe they’re struggling to squat to do their business, or they walk unsteadily at times.

Concerned that they may be developing arthritis, you whisk them off to the vet, hoping that a course of anti-inflammatories will do the trick. But the cause turns out to be more insidious and destructive: degenerative myelopathy.

What is degenerative myelopathy?

Degenerative myelopathy (DM) is a spinal disorder affecting dogs. It occurs spontaneously (without any trigger or warning) in adult dogs, generally between eight and 14 years of age.

In humans, there’s a similar condition known as Amyotrophic Lateral Sclerosis (ALS), or Lou Gehrig’s disease. Stephen Hawking (1942-2018) was one of the more famous people who suffered from this debilitating disease.

In a healthy spinal cord, the “white matter” tracts contain the nerve fibres that communicate between the brain and the limbs and send sensory information from the limbs back to the brain. With DM, the white matter degenerates, and communication between the brain and the limbs slowly becomes impossible. The condition predominantly affects the hindquarters.

Why did my dog get it?

DM is a genetic disorder. There’s a DNA test that can show which dogs are “clear” (extremely unlikely to develop DM), “carriers” (more likely to develop DM) and “at risk” of developing DM. This is, however, not a diagnostic test, and it cannot be used to confirm that a dog has DM. Also, a number of the “at risk” dogs never develop DM in their life.

Certain breeds appear to be predisposed, but it can occur in other breeds, including mixed-breed dogs. Male and female dogs are equally affected.

The test is useful for breeding programmes, especially for breeds that are predisposed to DM. In the past, DM was thought to affect mainly German Shepherds and some other large breeds, but currently the list of breeds where DM is a concern includes Boxers, Pembroke and Cardigan Welsh Corgis, Wire-haired Fox Terriers, Bernese Mountain dogs, Borzoi, Cavalier King Charles Spaniels, Chesapeake Bay Retrievers, Golden Retrievers, Great Pyrenean Mountain dogs, Kerry Blue Terriers, Poodles, Pugs, Rhodesian Ridgebacks, Shetland sheepdogs, Soft-coated Wheaten Terriers and Nova Scotia Duck Tolling Retrievers.

What signs should I look out for? Is it easy to diagnose?

The onset of DM in dogs is very gradual. You may notice the dog has difficulty walking up steps or getting in the car, reluctance to squat to defecate, an uncoordinated/wobbling walk with the hind limbs (a bit like the dog is drunk; this is called “ataxia”), and the dog dragging its back paws. Often one leg is initially more affected than the other.

With time, the legs become increasingly weaker, and the dog will find it more and more difficult to walk or even stand.

Eventually the dog will develop faecal and urinary incontinence (this means it has no control over when it pees and poops), and the weakness can progress to the front legs. From the first onset of symptoms to complete hindquarter paralysis takes about six to 12 months, but individual cases may vary.

The diagnosis of degenerative myelopathy is one of elimination. What that means is that there’s no specific test for DM, and the diagnosis can only be confirmed after the dog has passed away and its spinal cord is examined under a microscope.

Does it hurt?

Degenerative myelopathy is not a painful disease on its own. However, as the dog compensates for the loss of strength in its hindquarters, it can experience pain in other parts of its body, such as front legs, shoulders and neck. Also, the dragging of its feet can cause non-healing wounds.

The initial symptoms of DM can appear similar to a number of other conditions, such as a herniated intervertebral disc, cysts, tumours, stroke, infections or injuries. Your vet will rule out these options by taking a detailed history and using tests such as spinal x-rays, CT scan, MRI or myelograms.

Can I help my dog?

DM is a progressive debilitating disease, and currently there’s no curative treatment. And whilst DM doesn’t actually kill the dog, owners will generally elect humane euthanasia to stop their four-legged friend from suffering due to the deterioration of their quality of life.

It’s been shown that treatments such as physiotherapy, hydrotherapy, (electro) acupuncture and massage can slow down the progression of the disease. Some dogs will require pain relief, because, although DM isn’t painful, the dog can develop secondary issues as it compensates for its disability.

Slings, harnesses, wheelchairs and booties can make mobility easier for you and your dog.

None of these treatments are of the “one-size-fits-all” type and will have to be adjusted to what suits you and your dog. In some cases, this means that euthanasia is chosen shortly after the disease becomes apparent; in others, owner and dog seem to find a very happy balance for a longer period of time.

One of these happy balances is between Shauna and her dog, Lucy. Lucy has degenerative myelopathy, and Shauna has kindly offered to share her story with us all.

TESTIMONIAL STORY

LOVING LUCY

Written by Shauna Germishuizen

Professional photography by Nat Gold ZA

I adopted Lucy about two-and-a-half years ago at approximately 11 or 12 years old. She’s always been an active, happy, friendly little dog. She also has a mischievous streak.

We’d go walking on the sports field, and when it was time to go home, she’d sprint off in the opposite direction, with me in hot pursuit. It’s amazing how fast those little legs could take her. I’d eventually catch up with her, panting furiously, at the far end of the field and put her lead on to escort her back to the car.

Her leg collapsed under her

I first noticed there was something wrong with her legs just over a year ago. She was scampering around on the field, sniffing at something, and suddenly her right hind leg collapsed under her, and she generally seemed wobbly on her back legs.

I took her to the vet, expecting the diagnosis to be a pinched nerve, since she has a rather long spine for a Corgi-mix dog. This was confirmed by the vet, who thought it was indeed a disc or nerve problem because it appeared to have come on rather suddenly. I was issued strict instructions to give Lucy cage rest for two weeks and then see how she was doing.

It was incredibly difficult to keep Lucy quiet as she was so exuberant, but we managed to some extent. However, the weakness in her legs persisted after the two-week rest period. I was really distressed and at a loss as what to do next.

A devastating diagnosis

I took Lucy to an animal physiotherapist who confirmed that it was some kind of damage or wear-and-tear to her spine and that there was pinching of the nerve, making her legs weak. I was told to walk her on even ground only, not on soft sand or over stony areas. This rather limited our walks and put paid to beach frolics. I didn’t want to over-exercise her, so she went for short walks only at that stage, much to her disappointment.

I noticed during this period that Lucy’s right back leg was weaker than the left, and her claws were dragging on the road when she walked. She also seemed to be getting gradually weaker in both legs. This was a very stressful time for me, seeing this lively little dog finding it progressively more difficult to walk.

She’d wobble on her back legs, looking like a drunken sailor, and then overbalance from time to time. Nevertheless, she’d just pick herself up and continue undeterred. What a brave little dog!

At this point I was advised to go to an animal acupuncturist. The diagnosis from this specialist was that the weakness was progressive and could only be slowed down with treatment – not stopped or reversed. It was apparently a dying-back of the nerves supplying the hind legs. I subsequently had this devastating diagnosis confirmed by another vet.

The scientific term for this insidious and cruel disease is degenerative myelopathy. The nerves slowly die back from the feet upwards towards the spine.

Living in the moment

At this stage, Lucy’s had the disease for over a year, and she’s now no longer able to walk.

But, being the determined little dog that she is, she doesn’t let this disability get her down at all. She pulls herself around at speed with her front legs and is able to get around on her own – I often find her lying outside in the sun when it’s chilly in the house.

Lucy appears to be just as happy and friendly as before and seems to live in the moment. She doesn’t think about what she’s lost, only about how to get around in the present.

We still go for a walk on the sports field, only now we go with her sitting in a shopping cart that I’ve modified for her. She sits in there with a smile on her face, watching the scenery and other dogs passing by. Every now and then she wants to get out and examine something from close by. Then she’ll scoot along on her front legs, covering large distances to sniff out the pee-mails or scavenge something delectable that she finds on the grass.

I’ve learned a lot from Lucy about living in the moment. We shouldn’t mourn the past. We don’t know what the future will hold. All we have is now, and we have to make the most of the present moment. Lucy does this every day, in her exuberant, happy way.

And thank you to Happy Tails and Pets R Us Pet Strollers for sponsoring Lucy her very own pet stroller, Lucy loves it, and it’s making a huge difference to our daily walks.