Canine degenerative myelopathy is a neurodegenerative disease that affects the spinal cord of older dogs. It is a pathology that begins by affecting the hind limbs and, as it progresses, can also affect the forelimbs. Unfortunately, it is a disease with a serious prognosis, due to its difficult diagnosis and the lack of specific and curative treatments.
If you are interested in learning more about degenerative myelopathy in dogs, its symptoms, diagnosis and treatment, don't hesitate to join us at next article on our site, in which we will also talk about the forecast.
What is degenerative myelopathy in dogs?
Degenerative myelopathy is, as its name suggests, a degenerative disease that affects the spinal cord of dogs. It was initially known as “German Shepherd degenerative myelopathy” because this was the first breed in which the disease was described.
However, today it is known that it can appear in many other breeds, especially in large breeds such as:
- The Bernese Mountain Dog
- The Rhodesian Ridgeback
- The Boxer
- The Siberian Husky
This is a chronic disease, with a slow and progressive course, which affects dogs from advanced age causing a slow deterioration in hindlimb function, eventually leading to complete paralysis.
Symptoms of degenerative myelopathy in dogs
Canine degenerative myelopathy has a slow and progressive course. Initially, it begins as a thoracolumbar problem (of the spinal cord segment T3-L3) in which it can be detected:
- Ataxia or incoordination: crossing of the hind limbs when walking, wobble of the hip and problems estimating distances may be observed. If you want to know more about Ataxia in dogs: its causes and treatment, consult the following article on our site.
- Paresia (hind limb weakness): Difficulty going up or down stairs is common.
- Loss of proprioception: Dogs drag the toes on their hind limbs, causing wear and bleeding to be seen on the hind limbs. knuckles.
- Muscular atrophy: loss of muscle mass in the hind limbs
It is common that the signs are asymmetric, that is, they do not appear with the same pattern or the same intensity in the two hind limbs.
Over time, the neurodegenerative problem progresses to produce paraplegia, that is, complete paralysis of the hind limbs. If it continues to progress, it could lead to tetraplegia, that is, paralysis of the forelimbs and hind limbs.
You may be interested in taking a look at the following post about Paralysis in dogs: causes and treatment, here.
Causes of degenerative myelopathy in dogs
Since its discovery, multiple studies have tried to discern the etiology of canine degenerative myelopathy. These investigations tried to associate the disease with possible nutritional deficiencies, toxins, autoimmune defects, etc. However, at present the specific causes that give rise to this pathology remain unclear.
The most recent studies have identified as a possible cause the mutation of the SOD1 gene, which codes for the enzyme Superoxide Dismutase. The high incidence of degenerative myelopathy in specific breeds suggests that there is a genetic basis for the disease, so the finding of this mutation may lead to the discovery of the genetic component of this pathology.
It should be noted that the mutation in the SOD1 gene is also present in people with Amyotrophic Lateral Sclerosis (ALS), which has turned degenerative myelopathy into an animal model to study this human disease.
Diagnosis of degenerative myelopathy in dogs
The diagnosis of canine degenerative myelopathy is complicated. The tests commonly used for the diagnosis of spinal cord pathologies (x-ray, magnetic resonance imaging and cerebrospinal fluid analysis) are not usefulto detect this disease.
Therefore, the diagnosis must be based on:
- Neurologic exam: Depending on the degree of spinal cord degeneration, upper motor neuron signs or lower motor neuron signs may be detected. It is characteristic that there is no pain on palpation of the spine.
- Genetic test: a genetic test capable of detecting the SOD1 gene mutation is currently available. However, until the true etiology of the disease is confirmed, this test should only be indicative.
In short, in dogs with signs compatible with the disease, in which other spinal pathologies have been ruled out and that have the SOD1 gene mutation, a presumptive diagnosis of degenerative myelopathy. However, the definitive diagnosis cannot be reached with the live animal, since for its confirmation it is necessary to carry out a histopathological analysis after the death or euthanasia of the animal.
Treatment of degenerative myelopathy in dogs
Unfortunately, there is currently No specific treatment or cure for degenerative myelopathy.
Clinical trials are currently being carried out using inhibitors that prevent the accumulation of the SOD1 gene mutation, so it is expected that in the early future it will be possible to availability of a commercial therapy to combat degenerative myelopathy.
Until then, the only treatment that seems to extend the life expectancy of the animal is physiotherapy The rehabilitation program should include mobilization exercises, stretching, massages and muscle electrostimulation. Although this therapy fails to prevent degeneration of the spinal cord, it does help:
- Control the pain caused by tension or poor posture that the animal acquires as a result of degenerative myelopathy.
- Stop the onset of muscle atrophy (loss of muscle mass).
- Stimulate sensitivity.
- Work on coordination and balance.
In addition, it is important to take a series of measures to guarantee an acceptable quality of life in these dogs:
- A comfortable place should be provided: soft to avoid decubitus ulcers, but firm so that they can sit up easily.
- The feet must be protected with socks for dogs: to avoid the appearance of ulcers, in case they walk dragging their toes.
- It may be necessary to use harnesses: to raise the hind limbs or even specific wheelchairs for dogs, in the case of more advanced stages of the disease.
Prognosis of degenerative myelopathy in dogs
The prognosis for canine degenerative myelopathy is serious, since it is a degenerative disease with no cure. Its progress is relatively fast, so that in a period of between 6-12 months the dogs become paraplegic.
This unfortunately means that most dogs with degenerative myelopathy have to be euthanized in the interest of animal welfare. Otherwise, the degenerative process can affect the brainstem, aggravating the neurological condition and causing great suffering in the animal.
