Description and cause
Degenerative myelopathy is a progressive wasting disease affecting the hind limbs. DM occurs predominately in German Shepherds and Welsh Corgis, although it can on rarer occasions affect other breeds. The cause is unknown but genetic factors are suspected. There is a non-inflammatory degeneration of the axons in the white matter of the spinal cord, causing nerve impulses from the brain to fail to reach the hind limbs correctly. This will eventually lead to progressive hind limb weakness and paralysis.
Symptoms and diagnosis
Early cases can be confused with orthopaedic disorders, however proprioceptive defecits (poor foot placement) are an early indication of DM which are not seen so often in orthopaedic cases. Affected dogs are usually over the age of 5 years, symptoms progress over a period of time, 6 months to 3 years. Often the first sign an owner will see or hear is claw scuffing of the hind limbs. Progressive weakness of the hind limbs will initially cause the dog to loose balance, eventually the dog will loose weight bearing function completely. Thankfully this condition appears to be painless and most affected dogs seem almost to not notice and endeavour to carry on their daily lives as if unaffected.
Diagnosis is made by examination, the use of myelography and MRI scans are essential to rule out inflammatory diseases and compression of the spinal chord, which may respond to surgical treatment. There is now a DNA test available to help detect a genetic pre-disposition to DM (CDRM)
Long term prognosis for DM is poor. Some clinicians advise the use of vitamin supplements and amioncaproic acid, but the safety and effectiveness of this treatment is not greatly known. Please discuss this further with your veterinarian.
Hydrotherapy in an Aquatic Treadmill can help to maintain muscle use, enabling the dog to continue walking for longer than would otherwise be possible. Cardiovascular fitness is also maintained along with the strength of the front legs, both of increasing importance if owners are considering the use of a cart. The mental welfare of the dog is much improved by hydrotherapy, in the non weight-bearing environment all four limbs are able to work in the normal manner of a healthy animal. This freedom of movement will make for a much happier dog who can exercise more normally in the water. It is only when the disease progresses that the hind limb activity lessens, although the front limbs usually remain strong.
The use of carts
There is much controversy about the use of carts for dogs with hind limb paralysis. This is a decision that should be made on an individual basis. Some dogs cannot cope with using a cart while others, however, cope very well and gain much quality of life with one. Many owners also feel unable to put their dogs in mechanical devices, this has to be your decision, let your dog guide you.
There are some basic guidelines that should be followed when considering a cart:
- Look at many manufactures of carts. There are several designs and where one may not be suitable for your dog another may.
- Homemade carts are to be used with caution. The stability of these gadgets is crucial to their success, there is a fine line between a cart that works well, particularly at speed or on rough ground and another that tips your dog over causing injury and distress.
- Pressure sores are also an important factor to consider and must be avoided. This can be difficult if the balance of the cart is wrong, the harness holding the animal is not made of the correct material or fitted correctly. Pressure sores are painful and can lead to infection requiring prompt veterinary treatment.
- Hygiene is another issue to consider. As dogs with hind limb paralysis often suffer from incontinence, be sure your dog can be kept clean at all times and that the design of the cart allows for easy defaecation.