Spinal Muscular Atrophy in Brittany Spaniels

Brittany Spaniels along with some other dog breeds are predisposed to suffering from a condition that affects their spines. The disorder is spinal muscular atrophy which sees all-important motor neurons found in a dog's spinal cord as well as their brainstems die off or degenerate. The result is that impulses are not sent to a dog's muscles and this prevents them from contracting and causes them to freeze up. The condition is a motor neuron disorder that is also known as hereditary canine spinal muscular atrophy or HCSMA.

The condition explained

It is an autosomal dominant disorder and its progression and how it affects a dog depends on the breed as well as an individual dog. Motor neurons are valuable nerve cells found in a spinal cord. Their function is to transmit vital impulses to the body's muscles which then causes them to contract allowing a dog to move normally. When this function is negatively impacted in any way, it leads to their muscles seizing up because they are unable to contract thus preventing a dog from moving naturally.

Symptoms of the disorder

As previously mentioned, the severity of the disorder can vary from breed to breed and dog to dog, but the signs of there being something wrong include the following:

• Loss of muscle mass
• An abnormal gait
• Reduced reflexes
• A weakness in both front and back legs
• Very poor coordination
• Head tremours
• Lack of appetite and trouble swallowing
• Lack or diminished growth
• Unable to hold their head up
• Inability to move
• High temperature (body)

The different types Spinal muscular atrophy

There are various types of spinal muscular atrophy and each affects different breeds. These are as follows:

• Spinal muscular atrophy - Brittany Spaniels
• Focal spinal muscular atrophy - German Shepherds
• Motor neuron disease - Rottweilers
• Multisystem chromatolytic neuronal degeneration - Cairn Terriers

Causes of Spinal Muscular Atrophy

Motor neuron diseases in dogs are inherited, autosomal dominant disorders which means that a puppy would only need on copy of the mutated gene from one or other of their parents to inherit the condition.

Diagnosing the problem

A vet would need to have a dog's full medical history as well as their lineage. They would also need to be told of how any symptoms first presented themselves and at what time they first appeared. A vet would then examine a dog's gait at the walk before performing a neurological examination as well as the following:

• A pupillary light reflex
• Palpating muscles to check for atrophy
• Pelvic and thoracic limb reflexes
• A spinal check

Most vets would recommend carrying out a muscle biopsy which would be sent away to a laboratory for analysis. A dog would need to be put under general anaesthetic for the procedure to be carried out which means they would need to be kept in overnight at the surgery. Other tests a vet might want to carry out include the following:

• X-rays of a dog's limbs
• An electromyogram - this would record any electrical activity within the muscles and again, a dog would need to be fully sedated for the procedure to be carried out.
• A nerve conduction test

Treatment options

Sadly, there is no treatment nor is there a cure for Brittany Spaniels diagnosed as suffering from spinal muscular atrophy, nor are there any cures or treatment options for other types of motor neuron diseases that affect other breeds. As such, it is more a case of managing the disorder with the use of specific drugs and medication with an end goal being to improve a dog's neurological activity.

With this said, many dogs diagnosed with chronic spinal muscular atrophy go on to lead full lives, but they never put on condition and remain very thin and their symptoms are often mild, but progressively get worse. Some vets recommend that dogs with the disorder undergo physical therapy and will sometimes recommend acupuncture too.

Dogs suffering with the condition have been seen to improve after being aquatic therapy such as swimming or walking on underwater treadmills. The reason being that all pressure is taken off their legs and the fact that their muscle tone improves through walking on the treadmill and swimming.

Dogs that are carrying too much weight would need to be put on a special diet and any that have lost the use of their back legs could benefit from having wheels fitted to enable them to move around. Another therapy that a vet might suggest is neuromuscular electrical stimulation or NMES which gives off very low volt electrical charges with an end goal being to stimulate muscle contractions.

Prognosis

If the diagnosis is severe and the condition seriously impacts a dog's life, it is kinder to put them to sleep rather than let them suffer unnecessarily. With this said, if the progression of spinal muscular atrophy is slow, a vet would need to keep an eye on a dog's condition and to prescribe specific ways to improve their lives with a lot of Brittany Spaniels going on to lead full and active lives, but they should never be used in a breeding programme.