Degenerative Myelopathy in Your Dog

Degenerative Myelopathy (DM) is a progressive, incurable neurological disease that affects a dog’s spinal cord. 

There’s a gradual breakdown of the nerves which control the hind limbs. As a result, neurons in the spinal cord aren’t able to communicate with the brain.  Your dog might start showing signs of weakness and unsteadiness in their back legs when walking. These are early symptoms of the disease. 

As it progresses, full paralysis is, unfortunately, inevitable. DM is most commonly observed in certain breeds, and its onset is typically in the later stages of a dog's life. This means it can sometimes be misdiagnosed for arthritis, or other age-related conditions with similar symptoms.

Sadly, Degenerative Myelopathy is ultimately fatal. However, there are ways to maintain your dog’s quality of life and keep them relatively active, until the point where the disease takes over. This process can take months or, in some cases, a year or so.

DM in dogs is slow-onset and isn’t painful. It’s associated with a genetic abnormality. Both the upper and middle (thoracic) and lower (lumbar) parts of the spinal cord are affected, although symptoms are typically seen in the hind limbs first. These symptoms are often asymmetrical i.e. you’ll notice your dog struggling with weakness more on one side of the body than the other. 

Prognosis is poor: usually around one year after first visible onset of symptoms, a dog becomes unable to walk using their hindlegs.

Sadly, in the late stages of DM, the entire spinal cord will eventually be affected. This means the front legs become paralysed, and a dog will develop breathing problems, incontinence and be unable to eat. 

At this stage, your dog’s quality of life will have been profoundly compromised and euthanasia is the kindest approach for your dog.

For these reasons, a diagnosis of Degenerative Myelopathy can be very difficult to receive. As it’s a terminal illness, treatment is ultimately palliative rather than to halt or cure the disease. Witnessing the disease unfold can require emotional resilience, sometimes over a relatively long period of time.

Canine Degenerative Myelopathy has similar clinical signs to ALS (the most common form of Motor Neurone Disease) in humans. Degenerative Myelopathy is sometimes referred to as chronic degenerative radiculomyelopathy (CDRM).

Early Signs and Symptoms of Degenerative Myelopathy

Sometimes it can take a while for an owner to realise that what they’re seeing are Degenerative Myelopathy symptoms, rather than the normal ageing process, a bad knee, or touch of arthritis (for example). This is because the early symptoms can seem mild and innocuous. Sometimes, the vet’s only consulted when rear leg weakness becomes really apparent. 

Initially, your dog will start exhibiting signs of rear leg weakness and lack of coordination. To begin with, it might be just one back leg that seems weak. There’ll be gradual muscle wastage. Your dog may find balancing difficult, drag the back paws, or find it hard to get to standing after having been sitting or lying down.

Degenerative Myelopathy symptoms in dogs will also include:

• Scuffed Toenails - The nails of the back paws may suddenly seem very short or have become stubby. The quick may even be exposed. This is because a dog with DM isn’t able to pick up their paws as well, so the nails get worn down.
• Knuckling - The back paws will “knuckle” - become turned under - so that your dog’s walking on their knuckles.
• Swaying - It might look as if your dog’s hindquarters are swaying, even though your dog standing still
• ‘Drunken Sailor’ Walk - Your dog might look as if he’s staggering (ataxia i.e. incoordination within the nervous system), or cross his hind legs while he’s walking.
• Falling - Your dog will fall easily if pushed from the side
• Paw Scraping - The back paws are ‘scraping’, or dragging on, the ground when walking. The tops of the paws can become hairless from this, or have bleeding and open wounds from the dragging
• Difficulty Standing - You’ll notice your dog struggling to get up from a lying position
• Tail Position - This can be a very subtle clue. If your dog’s tail is no longer pointing upwards, and only horizontal when walking, it may be a sign that there are changes to the spinal cord.

As the spinal cord continues to deteriorate these symptoms will become more noticeable, and worsen over time. Sadly, as Degenerative Myelopathy progresses, a dog will become doubly incontinent, and develop complete hind end paralysis.

As the condition progresses, these symptoms worsen, eventually progressing to paralysis of the hind end. A dog usually loses the ability to walk using their hind legs within 6 to 12 months.

Weakness and paralysis of the front legs characterise the late stages of the disease.

Many of these clinical symptoms are also seen in other spinal cord and neurological diseases, so it’s important that your dog gets the correct diagnosis for the symptoms from which he’s suffering.

When you first take your dog to the vet, they will do a physical examination of your dog. Your dog might show a mild limp on a rear leg and show dropping of the hip as your dog steps forward.

Your vet will likely feel your dog’s paw, if they pinch the paws and your dog shows a loss of feeling in these paws, it is likely they might have Degenerative Myelopathy. Over time, the loss of feeling will show in both paws.

You vet will ask to see your dog walk, your dog will show wobbling or weaving when walking.

If your vet takes an X Ray, if they find no signs of hip dysplasia, bone tumours and the knees are in good health with no signs of a torn or pulled cruciate ligament knee / ACL, then this indicates it could be Degenerative Myelopathy.

Your vet might give your dog anti-inflammatory medication or pain killers, your dog will likely have Degenerative Myelopathy if these two types of medication have no or very limited effect on your dog. The medication will have no impact on your dog as DM is a neurological condition so anti- inflammatory or pain killer medication will have no impact.

Diagnosis Testing for Degenerative Myelopathy

Good news, you can do a gene test for Degenerative Myelopathy so you have a firm answer on whether your dog has DM or not.

With the help of your vet, you can submit a blood sample for gene testing, and if it comes back positive for the SOD-1 mutation, then your dog has Degenerative Myelopathy.

I think my dog has Degenerative Myelopathy

If you find yourself googling “What is DM in dogs?” because you suspect that your dog’s suffering from it, it’s essential to consult with a vet as soon as possible.  Your vet will take your dog’s breed, medical history and age into account. 

Your vet will do a thorough physical examination, This will likely include pinching your dog’s paw to test for feeling. A loss of feeling is a possible sign of DM. Your vet will also watch your dog’s gait, assessing for any limping, dropping of the hip as your dog moves forwards, or weaving and wobbling.  The knees will be checked for Cruciate Ligament issues.

Sometimes a dog’s prescribed anti-inflammatory medication or pain killers. If these medications don’t have any effect, DM is then suspected. This is because DM is a neurological condition, and so neither of these will make a difference to your dog’s symptoms.

Your dog will have blood tests (to exclude metabolic reasons for spinal cord dysfunction), neurological tests and imaging studies to help with diagnosis. X-Rays rule out hip dysplasia, bone tumours

Imaging may include an MRI scan to see the spinal cord. Less usually, a spinal tap (CSF  - cerebospinal fluid test) is done to exclude other diseases.

Both an MRI and CSF test need to be performed while your dog’s under anaesthetic.

There isn’t a diagnostic test for DM per se, although there are DNA tests to see whether your dog is in a genetically ‘high risk’ category for developing it i.e. has the genetic mutation associated with DM. 

Generally the diagnosis through a process of elimination. Other spinal cord and neurological conditions, such as arthritis, hip dysplasia, or IVDD, will be ruled out.

What Causes Degenerative Myelopathy in Dogs?

The causes of Degenerative Myelopathy aren’t fully understood. What is known is that dogs who are at an increased risk of developing it carry two mutated copies of SOD-1 gene. 

In DM the gene coding for superoxide dismutase (SOD-1) is mutated. Superoxide dismutase is a protein that’s responsible for destroying excessive free radicals in the body. Free radicals are part of the body’s natural defence mechanism but can be harmful if there are too many of them. When there are excessive quantities it results in cell death and a variety of degenerative diseases, such as DM. 

Dogs are categorised into:

• Those who don’t carry any mutation of the gene (clear); 
• Those who have one normal copy and one mutated copy (carrier);
• Those who have two copies of the mutated gene (higher risk). 

Even a higher risk dog may avoid developing DM. There are various theories as to why they manage to evade it. It might be because the dog’s natural lifespan ends before DM has a chance to develop. It might be because of other genetic or environmental factors of which we’re still unaware.

Nonetheless, if you suspect your dog carries two mutated copies of the SOD-1 gene, or know a dog in their lineage has had DM, your dog should have a DNA test. There’s an inherited component to DM and so it’s best to avoid passing it on through breeding if your dog does carry both copies of the gene mutation.

Degenerative myelopathy is typically divided into four stages to describe the progression of the disease. These stages are based on the severity of clinical signs and the level of disability. It's important to note that not all dogs will progress through these stages at the same rate, and some may skip certain stages. Below Stages 1-4 are described.

Stage 1: In this initial stage, the symptoms of degenerative myelopathy are often subtle and may go unnoticed for some time. Dogs may experience mild hind limb weakness or a slight loss of coordination. They might stumble occasionally or have difficulty getting up after lying down for a while. There may be knuckling of the paws, dragging of the feet/wear on the toenails, and stumbling/crisscrossing of the hind limbs. Often owners may attribute these symptoms to normal ageing or arthritis, and they may not seek veterinary attention at this point. Stage 1 can last for several months to a year.

Stage 2: In this stage, the clinical signs become more noticeable and concerning. Dogs exhibit moderate hind limb weakness and may drag their hind feet when walking, with increased level of paralysis. They will increasingly struggle to rise from a lying or sitting position. Muscle wasting (atrophy) in the hind limbs will become apparent. Dogs may or may not still be able to walk but will have an unsteady gait. Many dogs in this stage require mobility aids such as wheelchairs to move around. Incontinence of both bladder and bowels often becomes a problem. This stage can also last for several months.

Stage 3:  This stage is characterised by significant loss of coordination and hind limb paralysis. Dogs will struggle to stand without assistance and fall over when attempting to walk. They may drag themselves using their front legs when unable to walk or stand properly. The hind limb muscle atrophy becomes pronounced. Front limbs often start to become noticeably affected also, with increased weakness. Faecal and urinary incontinence and a change in bark or other vocalisations may be noted. This stage can last several months. Euthanasia is sometimes considered to prevent further suffering.

Stage 4: This is the most severe stage of degenerative myelopathy. The dog is generally completely paralysed in all four limbs, has muscle atrophy affecting the entire body, has faecal and urinary incontinence, change in vocalisation, difficulty swallowing food/water, and difficulty breathing. Dogs in this stage typically experience a significant decline in their overall quality of life. Euthanasia is often felt to be appropriate to prevent further suffering.

Can I Prevent my Dog from Developing Degenerative Myelopathy?

The only way to prevent Degenerative Myelopathy is through selective breeding i.e. puppies bred from two parents who both have two normal copies of the SOD1 gene. Other than that, there’s no way to prevent a dog from developing it. 

If your dog has a healthy lifestyle, is the right weight, and is kept active for as long as possible (see below) this can possibly slow the progression of the disease. The life expectancy of a dog diagnosed with DM is usually around 130-255 days. 

There’s a study that’s shown that if a dog remains active for longer by using a wheelchair, has physiotherapy and photobiomodulation therapy (aka low level laser therapy), then longevity might possibly be increased. 

What Dog Breeds Suffer from Degenerative Myelopathy?

It seems that German Shepherds, Boxers, Pembroke and Cardigan Welsh Corgis, Wire Fox Terriers, Bernese Mountain Dogs, Borzoi, Cavalier King Charles Spaniels, Chesapeake Bay Retrievers, Golden Retrievers, Great Pyrenean Mountain Dogs, Kerry Blue Terriers, Poods, Pugs, Rhodesian Ridgebacks, Shetland Sheepdogs, Soft-Coated Wheaten Terriers, and Novia Scotia Duck Tolling Retrievers are all breeds that are more susceptible to DM.

What Ages Suffer from Degenerative Myelopathy?

Degenerative Myelopathy typically manifests in dogs older than five years, with an average onset age of around 9-14 years.

Treatment Options: How Can I Help My Dog?

When your dog’s been diagnosed with Degenerative Myelopathy, their quality of life and wellbeing should be at the heart of every treatment decision you’re making. The progression of the disease is inevitable - everything is a question of ‘when, not if’. Treatment is, by definition, palliative.

There are four defined stages to the disease, and obviously the higher the stage, the more difficult your dog’s life becomes. The last stage of the disease can progress quite suddenly, and lead to you having to make difficult decisions on behalf of your dog.

Dr Alice Villalobos developed a Quality of Life Scale to help people track how their dog is doing if faced with a terminal illness. The 7 criteria she highlights are:

1. Hurt
2. Hunger
3. Hydration
4. Hygiene
5. Happiness
6. Mobility 
7. More good days than bad

You can read more about it here

With DM, keeping your dog mobile for as long as possible is extremely important. Wheelchairs allow your dog to move around and go for walks, which will also help with their happiness and hygiene (wheelchairs are designed so your dog can urinate and defecate while in them, although dogs can’t squat in a wheelchair).  

The advice is to get your dog used to a wheelchair before the disease has progressed to the stage where they actually need it - i.e the early to mid-stage of DM. 

It’s a fallacy that if your dog’s in a wheelchair, it’ll make them lazy. The reality is, with a diagnosis of DM, a wheelchair is a crucial mobility tool.

Other approaches to help manage the disease and its symptoms are:

• Physiotherapy and Hydrotherapy - Keeping core strength and muscle tone for as long as possible.
• Acupuncture - Done once or twice weekly, can work to stimulate the nerves in your dog’s hindquarters.
• Exercise - Both active (walking, climbing stairs, weight shifting exercises) and passive (stretching and range of motion maintenance).
• Canine Massage Therapy - Massage helps keep blood and fluids circulating.
• Photobiomodulation Therapy - This can have very positive results in extending lifespan if used the right amount when a dog’s suffering from Degenerative Myelopathy.
• Medication - The progression of clinical signs has been shown to be slowed with a combination of epsilon-aminocaproic acid, N-acetylcysteine, prednisone, and vitamins B, C, and E.
• Nutrition - Some owners research and follow specific nutritional protocols to help their dogs. Depending on the individual dog, this can make something of a difference.
• Other Mobility Issues - Ensure that there aren’t any other mobility issues at play. DM is generally a pain-free condition so if your dog is showing signs of pain when walking, that may be a concurrent condition, such as arthritis.

BIKO Physio Dog Brace - This mobility aid is designed to give more proprioceptive feedback to your dog’s brain, and helps strengthen the leg muscles. It helps your dog’s legs to move in a straight line (lessening the leg crossing that often characterises the later parts of the early stages of DM), and makes walking and turning easier. Owners report it can help keep their dogs walking for as long as possible.

Q: Hello, we have a Labrador who has just been diagnosed with very early stages of degenerative myelopathy. At the moment he just has some very slight weakness in his left hind leg but we have been warned by the vet that he will only get worse. We are wanting to be prepared and be able to support him with his progressive hind weakness, what can you recommend please?

A: Thank you for your query about your Labrador who is in the early stages of myelopathy. We're sorry to hear about his diagnosis, but here are some things which you can have a look at which hopefully will be helpful.  Firstly, we would recommend these anti-slip socks that may give him more purchase when he's getting up from laying down, particularly if you have wooden floors.

In terms of further support, you could also consider a Walkabout rear lift harness to help give him support as he gets up. This harness will aid with lifting or carrying your dog or to aid you to walk dogs with rear leg weakness. It wouldn't however provide support on its own. This one can be left on all day, if necessary:

We have a range of back braces such as the Biko Brace which are aimed at dogs with degenerative myelopathy however our customer feedback is that these are not particularly helpful. In addition, the progression of degenerative myelopathy can be fast and so they can ‘outgrow’ its usefulness relatively quickly.

Lastly, this is not something which is suitable for your dog currently as sounds like he is still able to get around fine but is worth thinking about as things progress. For dogs that are weak or paralysed in their back legs, the dog wheelchairs are a great option to keep them mobile, as the wheelchair will totally support your dog's weight. Their back legs can be put up in the stirrups or they can still use their back legs if they have a bit of movement and you want to help maintain muscle. 

How To Help Around The House

Your dog will need increasing levels of help around the house as the disease progresses. 

A rear-lift or full-body support harness will likely be invaluable, particularly if you’ve got stairs or need to get your dog in and out of the car. A ramp can also help with stairs.

The GingerLead Support Sling is another popular support that is useful when helping your dog out to go to the toilet.

Provide non-slip surfaces such as carpets, yoga mats or get your dog non-slip socks. This is to give your dog a little more traction as their rear legs become weaker.

At some point, you’ll have to start dealing with episodes of incontinence. Make sure that your dog’s bedding is washable, and washable dog incontinence pads might also be helpful. Ensure your dog is kept washed and fresh, so that they’re not suffering from ‘urine scald’. 

Urinary tract infections can sometimes be a secondary effect of incontinence, so ask your vet if this is something that needs keeping an eye on.

Conclusion

Degenerative Myelopathy is a very distressing diagnosis. As with any terminal illness, coming to terms with the implications can take time. The disease demands that you’re very closely attuned to your dog’s needs and have the stamina to give your dog the necessary care, particularly in the later stages of the disease. It might be helpful to reach out to other dog owners who’ve had experience of looking after dogs with DM for support and information.

However, the right support can help extend a dog’s quality of life. Wheelchairs can really make a significant difference to your dog’s mobility and emotional wellbeing.

Most owners know when the time has come to relieve their dog’s suffering through euthanasia. Until that moment, working in close conjunction with your dog’s vet and physiotherapist can help your dog live with the condition as well as possible, for as long as possible.