Degenerative Myelopathy in Your Dog

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

Degenerative myelopathy (DM) also sometimes known as chronic degenerative radiculomyelopathy (CDRM), is a non-painful but progressive and incurable neurological disease that affects a dog’s spinal cord. It involves a gradual breakdown of the nerves in the spinal cord which control the hind limbs.

As a result, neurons in the spinal cord aren’t able to communicate with the brain. Early signs or symptoms of degenerative myelopathy in dogs is often weakness and unsteadiness in their back legs when walking.

As the disease progresses, a dog will gradually develop weakness and an abnormal gait in their hind limbs. Usually it is not completely symmetrical, so your dog will struggle with greater weakness on one side of their body, than the other. As degenerative myelopathy advances, it causes progressive paralysis of the hind limbs.

Very sadly the entire spinal cord will eventually become affected—causing gradual paralysis of their entire body and if left to progress this leads to forelimb paralysis and eventually problems with breathing, continence and eating.

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 in your dog can require a lot of emotional resilience from you as an owner; deciding when it is the right decision to have them euthanised.

While there are ways to maintain your dog’s quality of life, keeping them relatively active until the point where the disease takes over, one of the hardest parts is recognising at which stage your dog’s quality of life becomes compromised and euthanasia is the kindest approach for your dog.

Early Signs and Symptoms of Degenerative Myelopathy

Sometimes it can take a while for an owner to realise that what they’re seeing in their dog is degenerative myelopathy symptoms, rather than the normal ageing process.

Due to early symptoms being mild or innocuous, they can often be put down to your dog having a touch of arthritis or a bad knee for example. Often owners only seek help from their vets once symptoms become more obvious and back leg weakness more profound.

There is no definitive test for degenerative myelopathy, diagnosis is more often reached by ruling out all other likely causes or diseases.

Degenerative Myelopathy Symptoms 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.
• Jumping and climbing - They may struggle or no longer be able to perform tasks which they previously used to, such as jumping into the back of your car or climbing the stairs etc.
• Muscle wasting - Sometimes this is asymmetrical but generally after a while becomes symmetrical

As the spinal cord continues to deteriorate these symptoms will become more noticeable and worsen over time, eventually progressing to paralysis of the hind legs/back and double incontinence.

A dog usually loses the ability to walk using their hind legs within 6 to 12 months. Weakness and paralysis of the front legs occurs in the late stages of the disease.

As always, if you suspect your dog may have degenerative myelopathy, it is important to consult with your vet for a proper diagnosis.

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 Degenerative Myelopathy is a neurological condition so anti- inflammatory or pain killer medication will have no impact.

The Degenerative Myelopathy Test

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.

What Causes Degenerative Myelopathy?

What causes degenerative myelopathy is not fully understood, there is a known genetic factor, however not all dogs who test positive for this genetic abnormality go on the develop degenerative myelopathy, which indicates there are other contributing factors which, at this time, are not known.

It is thought the most common form is due to a genetic mutation in a gene coding for superoxide dismutase 1 (SOD 1). Dogs who carry either one or two copies of the mutated SOD 1 gene, have an increased risk of going on to develop degenerative myelopathy. SOD 1 is a protein responsible for destroying free radicals in the body.

While free radicals are part of the natural defence mechanism, they become harmful when they are produced in excessive quantities. Excessive quantities of free radicals, causes cell death and a variety of degenerative diseases, of which degenerative myelopathy is one.

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)

While a dog with two copies of the mutated SOD 1 gene is at an increased risk of developing degenerative myelopathy, it is not guaranteed. This has led vets and scientist to conclude that there must be further contributing factors, which we are not yet aware of at this time.

DNA testing is available, this can help to identify those dogs who are deemed as ‘clear’, ‘carriers’ or ‘at risk’. This is sometimes used by responsible breeders to determine whether or not to breed from their dogs, however a genetic test does not confirm degenerative myelopathy.

So, while it is considered extremely irresponsible to breed from a dog which is flagged as a ‘carrier’ or ‘at risk’ of degenerative myelopathy, it is not a certainly that they will go on to develop it in their lifetime.

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.

What Dog Breeds Suffer from Degenerative Myelopathy?

Previously degenerative myelopathy was predominantly regarded as a disease of German Shepherds however, in recent years the disease has been identified in many other breeds of various sizes and it is no longer considered a “large breed” problem. It can affect any breed of dog however, those which are considered most at risk are:

• Poodles
• Boxers
• Borzois
• Pembroke and Cardigan Welsh Corgis
• Bernese Mountain Dogs
• Cavalier King Charles Spaniels
• Great Pyrenean Mountain Dogs
• Rhodesian Ridgebacks
• Shetland Sheepdogs
• Chesapeake Bay Retrievers, Golden Retriever and Nova Scotia Duck Tolling Retrievers
• Soft-Coated Wheaten Terriers, Kerry Blue Terriers and Wire Fox Terriers

At What Age Does Degenerative Myelopathy Start?

Degenerative Myelopathy typically manifests in dogs with an average onset age of around 9-14 years. It is extremely rare to see Degenerative Myelopathy in a dog younger than five years of age.

How To Help Around The House

There are a number of ways in which you can help your dog manage their degenerative myelopathy on a day-to-day basis when at home.

• Getting your dog some rubber anti-slip socks or boots to put on their back feet can help prevent your dog from slipping, giving them extra support and traction if they have lost muscle tone. This is especially helpful on wooden or tile floors which can be slippery. Equally putting carpets down if you have areas of floor which your dog is slipping on can be equally helpful

• Similarly protective boots or socks can prevent your dog ripping nails or developing sores if they are dragging their feet or knuckling 

• Try not to give your dog a bed which is too high or too low - A bed which is at their chest height means that your dog does not need to climb up or lower themselves down too far and makes it easier for them to get in and out of their bed

• A rear lift harness can help you help your dog on a day-to-day basis whether it is supporting them when toileting, getting in and out of the car, up and down steps or in and out of their bed

• As Degenerative Myelopathy progresses and your dog becomes incontinent, good hygiene is vital. Developing ‘bed’ or pressure sores is common. Urine and faeces can easily excoriate your dog’s skin, creating sores which are slow to heal and leave them at high risk of an infection developing. Further due to paralysis and not being able to adjust their position easily, your dog can develop sores from being in one position for too long and you may need to manually turn or reposition your dog every few hours

• Geeting your dog into a dog wheelchair can really transform their lives and prolong their time of being able to be independent and have a greater quality of life. Read more about this further below in the Treatment section

Treatments for Degenerative Myelopathy

When your dog’s been diagnosed with degenerative myelopathy, their quality of life and wellbeing should be central to every treatment decision you’re making. The progression of the disease is inevitable – it’s is a question of ‘when’ not ‘if’.

Because there is no cure for degenerative myelopathy treatment is by definition palliative; focusing on managing the symptoms and maintaining your dog's quality of life. This may involve physical therapy, the use of mobility aids such as wheelchairs or slings and managing urinary and faecal incontinence.

Integral to the treatment plan that you make for your dog will involve constantly assessing their quality of life and recognising at what stage this compromised and euthanasia is the kindest approach for your dog.

With Degenerative Myelopathy, keeping your dog mobile for as long as possible is extremely important and cannot be overstated enough. Wheelchairs allow your dog to move around at home and in the garden as well as go for walks. This can give your dog a huge boost in their quality of life and be literally life-changing for them. In addition, it can also really help improve their hygiene as wheelchairs are designed so your dog can urinate and defecate while in them, without having to squat.  

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 Degenerative Myelopathy. It’s a fallacy that if your dog’s in a wheelchair, it will make them lazy or will further reduce their muscle mass.

The reality is, with a diagnosis of degenerative myelopathy, a wheelchair is a crucial mobility tool aimed at supporting your dog. Wheelchairs can be either two wheeled where they just support the hind legs or a quad, which gives support to your dog on all four limbs.

This brace is a mobility aid and 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 degenerative myelopathy) and makes walking and turning easier. Owners report it can help keep their dogs walking for longer than they otherwise would.

Other Approaches to Managing the Disease:

• Physiotherapy and Hydrotherapy - Keeping core strength and muscle tone for as long as possible. You should try to maintain both active exercise (e.g. walking, climbing stairs, weight shifting exercises) and passive exercise (stretching and range of motion maintenance) – your physiotherapist or vet can recommend which would be most beneficial for your individual dog

• Acupuncture - Done regularly, can sometimes help to stimulate the nerves in your dog’s hindquarters. Similarly Canine Massage Therapy can help to keep blood and fluids circulating.

• Photobiomodulation Therapy – This is a relatively new treatment for degenerative myelopathy and can have very positive results in extending lifespan

• 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. degenerative myelopathy is generally a pain-free condition so if your dog is showing signs of pain when walking, that may be a simultaneous condition, such as arthritis.

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.