Myotonia Congenita

Affected dogs present as puppies for prolonged muscle contractions, especially after resting. This leads to visibly appreciable muscle rigidity and a stiff, hopping gait. The tongue muscle is often affected as well, causing affected dogs to have a characteristic protruding tongue. Affected dogs may also have difficulty swallowing or may regurgitate their food after eating due to involuntary muscle contractions.

Signs first appear in puppies.

Genetic testing, clinical signs, EMG, and muscle biopsy can be used to diagnose this disease.

There is no treatment currently for this condition, but physical therapy can be beneficial.

Talk to your vet about your dog’s myotonia congenita result so you can plan appropriate care and monitoring.

Signs such as muscle stiffness after rest often improve with gentle movement or warm-up activity.

Avoid sudden or strenuous exercise, and provide good traction at home to help your dog move safely.

Learning gentle stretching or physical therapy techniques from your vet may also help keep your dog comfortable and flexible.

This mutation was first described in the Australian Cattle Dog.

Penetrance: This disease is inherited in an autosomal recessive manner, meaning that affected dogs must have two copies of the mutation to show clinical signs.

Gene

CLCN1 (Exon 23)

Inheritance type

recessive

Clinical category

Muscular

Citations

1. Finnigan et al 2007

• Australian Cattle Dog
• Border Collie
• Australian Kelpie
• McNab
• Stumpy Tail Cattle Dog