Multisystem chromatolytic neuronal degeneration in Cairn Terriers

Dogs like people can be affected by nervous system disorders and as such a lot of research has been carried out into this type of condition which means there's a lot more information available than there is for some other more common congenital and hereditary disorders known to affect specific breeds. Nervous system disorders are also often referred to as metabolic disorders and one in particular that affects Cairn Terriers, has recently been identified which is known as multisystem chromatolytic neuronal degeneration.

The condition explained

There are several breeds that are predisposed to suffering from metabolic disorders and the Cairn Terrier is one of them. Although rare, multisystem chromatolytic neuronal degeneration has been identified in the breed. It is an inherited motor neuron disorder that negatively impacts essential impulses that need to be sent to a dog's muscles which allows them to move naturally. When the impulses are not received, muscles seize up and freeze. The disorder is progressive which results in a dog eventually being unable to stand up because they are unable to support their own weight due to weakness.

Unfortunately, although studies have established that the condition is inherited, the mode of inheritance remains unknown and more research is needed to establish why some breeds are more predisposed to inheriting this form of motor neuron disease whereas others are not.

Symptoms associated with the disorder

The clinical signs associated with this motor neuron disorder can be mild or severe. The symptoms a dog typically shows when they are suffering from the condition are as follows:

• Progressive weakness
• Reduced reflexes
• An abnormal gait
• Loss of muscle mass which is referred to as muscle atrophy

Diagnosing the condition

A vet would need to have a dog's full medical history and their lineage before carrying out a full neurological examination. The tests a vet would typically recommend carrying out in order to establish a definitive diagnosis could include the following:

• A muscle biopsy
• Nerve tests (electromyogram)

Treatment options

Sadly, there is no treatment for Cairn Terriers that have been diagnosed as suffering from multisystem chromatolytic neuronal degeneration. The disorder, as previously mentioned is progressive and a dog's condition might worsen quickly or it could get slowly worse as it varies from dog to dog. Should a dog's condition be deemed very severe, it is often much kinder to put them to sleep rather than to let them suffer any further unnecessarily because their quality of life is so negatively impacted.

What about breeding?

Any Cairn Terrier diagnosed as suffering from a mild form of the disorder should be spayed or neutered and not used in a breeding programme. Any lines where a dog has been diagnosed as suffering from multisystem chromatolytic neuronal degeneration should be identified and any dog from these lines should not be used for breeding purposes until they are at least 3 years old which is good breeding practice as it allows for them to be identified as being carriers or not.