There is much which remains under debate with Pug Myelopathy in the veterinary and scientific field, including its name. It is sometimes referred to as subarachnoid diverticulum (SAD), Pug ataxia, facet hypoplasia, Pug constrictive myelopathy (CM) or merely ‘rear weakness’. However, they all refer to the same spinal condition, which causes ataxia and paralysis of the hind legs. It typically progresses over a period of 1-4 years, but unlike degenerative myelopathy, it does not spread into the forelimbs or rest of the dog’s body.

There are a range of conditions such as IVDD (slipped discs), spinal tumours and degenerative myelopathy which Pugs suffer from, however despite being a little-known condition, it is thought that in fact Pug Myelopathy is the most prevalent cause of mid-back spinal cord problems in pugs.

Although most commonly seen in Pugs, Pug Myelopathy is not limited to this breed. In theory any breed of dog can develop Pug Myelopathy, although also recognised as being most at risk are; French bulldogs, English bulldogs and Boston terriers. As research and knowledge increases however, it is entirely possible that other breeds could join this list.

Signs and symptoms of Pug Myelopathy

One of the things which can be very distressing as an owner of a dog with pug myelopathy, is that your dog can seem otherwise completely normal and their usual happy and healthy self. Pug Myelopathy (unlike IVDD) is mostly characterised by being a pain-free condition, even on palpation of the affected area.

Pug Myelopathy typically presents with the following signs and symptoms:

• Ataxia; dogs may have difficulty coordinating their movements, leading to an unsteady gait, sometimes referred to as the ‘drunken sailor’ walk
• Dogs affected by Pug Myelopathy usually develop progressive hind limb weakness, which worsens over time. Initially you may only notice that your dog’s feet and/or toe nails are scuffed
• Dragging or ‘knuckling’ of hind legs. As the disease progresses, affected dogs may increasingly drag their hind limbs or knuckle over their paws. This eventually progressed to complete paralysis
• Reflexes in the hind limbs may become diminished or absent
• Generally, a symptom which develops later on is incontinence. As the condition advances, dogs may lose control over either or both their bladder and bowel functions

If you suspect your dog may have Pug myelopathy, it is really important that they are assessed and diagnosed as soon as possible, for the best possible outcome. Ideally your dog should see a vet who has some experience in Pug myelopathy. Your vet is likely to refer your dog to a specialist neurologist. Diagnosis is usually done through a combination of physical examination, imaging (MRI) and sometimes cerebrospinal fluid analysis. It is also often a question of ruling out other possibilities such as IVDD or degenerative myelopathy.

For this reason, sometimes genetic testing is done, as although it is not possible to genetically test for Pug myelopathy, it can flag up other conditions. It is important to remember however, just because your dog is flagged as being ‘at risk’ of a disease (such as degenerative myelopathy) through genetic testing, it does NOT mean that that is necessarily the problem, it just indicates that they are a risk of developing or have the potential to develop that condition.

Several other well documented conditions in Pugs also cause symptoms of hind weakness or paralysis, such as hemivertebrae (usually young dogs); Intervertebral Disc Disease (IVDD); spinal cord tumours and spinal arthritis in older dogs. It is therefore important to have the prompt input from a vet knowledgeable in PM and/or a referral to a specialist dog neurologist, if your dog has symptoms for an appropriate diagnosis.

As touched on above, the knowledge base on pug myelopathy is still growing however, it is believed that it occurs due to a number of spinal abnormalities, causing either vertebral bone changes and/or spinal cord compression. Interestingly, in studies which tried to pinpoint the exact cause of pug myelopathy, although the majority of pugs had ‘defective’ spinal bones, not all of them had the neurological symptoms of pug myelopathy. This indicates that it is more likely to be caused by spinal cord compression, and has led to it generally being accepted as being the main cause of Pug myelopathy, although further research is needed.

Spinal cord compression happens when a fluid-filled pocket or pockets (lesions) develop on the outside of the spinal cord, in the subarachnoid space and compresses the spinal cord. Although it is completely normal for the spinal cord to be surrounded by cerebrospinal fluid, this lesion or lesions become so dilated that it puts pressure on the spinal cord, causing compression and therefore neurological symptoms of paralysis. It can also sometimes, although not always, lead to incontinence issues.

It is thought that there is a genetic factor to the development of Pug myelopathy however, unlike degenerative myelopathy, there is no genetic test which can be performed, to help and identify the presence or risk of Pug myelopathy. This is particularly hard when thinking about breeding from your pug.

However, as a breeder there are some steps which you can take. Sadly, like with so many of these conditions which our purebred dogs suffer from, it is through selective breeding on our part, which has led to these conditions developing and becoming so prevalent. Purebred dogs, by their very nature, are homozygous, meaning they have little genetic variation. So, where there is a population of registered, purebred dogs, a lot of interbreeding occurs through multiple generations. This is exacerbated by dogs then being bred for their ‘ideal’ or ‘standards’ of confirmation. Notoriously this has led to extremes of confirmation, with Pugs becoming increasingly brachycephalic (flat-faced) and also having an overly compact spine. This is directly linked to the development of Pug myelopathy. In a move to combat this, some Pug breeders have tried to bring diversity into the genetic pool. Two examples of these are Retro Pugs and Old German Pugs. Neither of these variations have, or carry, the spinal defects which lead to Pug myelopathy developing.

What Age does a Dog get Pug Myelopathy?

Generally, onset of Pug myelopathy is seen in middle to later-aged dogs, between the ages of 9-12 years. Although it has been seen in dog as young 2 years of age, this is considered very unusual.

As of this time, there is no cure for Pug myelopathy however, this does not mean that your dog cannot live a long and very happy life. Dogs affected with Pug myelopathy are usually pain free and can have excellent quality of life.

For some dogs surgery is an option, but it has been found to only be effective if done in the very early stages and then only delays and does not prevent disease progression and paralysis. So while short-term it can be great, long-term outcomes are poor. However, this is a constantly evolving field and it is hoped that successful surgery will emerge in the future.

One of the most effective ways of treating Pug myelopathy is through physical therapy, in conjunction with a wheelchair. A combination of exercises, which aim to help maintain and enhance muscle tone and mobility, can really help your dog. Similarly moving your dog into a wheelchair while they still have some function in their back legs is ideal. Dogs who are put into a dog wheelchair in the earlier stages do much better than those who wait until the later stages. Partly this is because your Pug needs to stay motivated to be active and long periods of inactivity and paralysis mean they lose some of this motivation.

A wheelchair can be lifechanging, enabling your dog to still enjoy an active life, despite paralysis or reduced function of their hind legs. A wheelchair takes the weight off their back legs, while still supporting them, so they can remain active.

There are different options for your dog while they are in their wheelchair. Their legs can either be completely supported (if they have total paralysis) or there are elastic stirrups, so your dog can continue to use their legs, if they still have some mobility. This will also help your dog to maintain muscle mass and mobility, even when using the wheelchair.

One other aspect of caring for a dog with Pug myelopathy monitoring continence. For some dogs with Pug myelopathy their paralysis can progress and include paralysis of the bladder and bowels. It is critical your dog is carefully monitored for its ability to completely empty the urinary bladder several times a day. There are some excellent resources online which give detailed descriptions of how this can be managed.

How to help your dog around the house

One side effect of Pug myelopathy is incontinence due to paralysis affecting not just the hind limbs, but also the bladder and bowels. This does not happen in all cases but it is important that you monitor your Pug for signs of urinary retention or an inability to pass a bowel motion. Dog nappies are sometimes used to manage incontinence however, this often causes your dog to develop recurrent urinary infections, so are best avoided if possible.

Q: My pug has spinal problems that have caused weakness in his back legs. He can walk but he's unstable and he sits a lot. I've tried a sling but it was no good, so I think a set of wheels for walk time will get him moving more. He can still potter around at home without wheels but having wheels would allow him to play with his pug family (we have 2 others who are very active). Should I send you a video of him? 

A: He looks like he would be a perfect candidate for wheels as his front legs are strong and he is in good condition. Wheels would help him get around and join in with the family activities, whilst taking the weight off his back legs and giving him support.  He would still be able to use his back legs whilst in the wheelchair but if they were getting tired you would be able to put them up in the stirrups that come with the kit.

Q: I am looking to buy a wheelchair for my French Bulldog. She has become quite wobbly on her back legs but is still relatively young, is otherwise well and so enjoys being out and about. We have been advised by our vet to think about moving her into a wheelchair, do dogs adapt well to these and what sort of attachments will we need?

A: The wheelchairs are great for dogs that have weak back legs, they usually adapt really well to them and are soon up and running.  They can get a bit tired at first because they will be doing more exercise than they are used to, but they soon build up fitness. The wheelchair kit comes with everything you need but it is possible to buy different harnesses and belly supports, which might be more comfortable if your dog is going to use the wheels for many years.

One thing to consider if your dog is going to be in a wheelchair long-term however is which make of wheel chair you decide to go for. Walkin Wheels are excellent wheelchairs, which receive very good customer feedback. Dogs seem to adapt really well to these and get excellent quality of life in them; however long-term they can have some limitations and it is therefore worth looking into Eddies Wheels.

Eddies Wheels have slightly different biomechanics, which load less weight and pressure on your dog’s shoulders, making weight distribution more equal. These wheelchairs however are custom-made for each individual dog and therefore can be costly. As a long-term investment, it is defiantly something that we would recommend although that is not to say that Walkin Wheels are not a good choice.

Q: Hello, my dog has hind leg weakness which is causing her back legs to spay out, is there something which you can suggest which would help prevent this?

A: We have the Walkin Traction Dog Socks, these have a strong non-slip, waterproof silicone base and they would help to stop your dog from slipping or splaying out.  They also have Velcro around the top of the sock part to help keep them on.

Q: Hi, I am looking for some advice please. My 8 year old dog has just been diagnosed with degenerative hind weakness, he is a still able to walk but his back legs appear to become weak and wobbly at times.

A: If your dog is likely to have permanent degeneration (such as Degenerative Myelopathy or Pug Myelopathy or similar) and will not be able to use his back legs again, it would be best you get him into a wheelchair sooner rather than later. This will allow him to still exercise and go on walks like normal and have a good quality of life, but the wheelchair will take the weight off his back legs. They are able to still move/use their back legs to some extent which will help to maintain muscle tone for as long as possible, but the weight will be taken off them.