Spinocerebellar Ataxia, Late-Onset Ataxia, LoSCA

Signs of cerebellar disease include: dogs have an uncoordinated gait (ataxia) with stilted "toy soldier" leg movements. They can display "intention tremors," where a stretched out limb or head shakes more and more violently as it approaches its target. At rest, dogs sometimes display a "truncal sway;" their spinal muscles have lost their fine-tuning, pulling the spine (and everything attached to it) back and forth in a struggle to maintain balance. The muscles of the eyes have also lost this fine-tuning, leading to a rhythmic eye flicking (nystagmus).

Unlike other SCAs in the Russell Terriers, loSCA begins between six and twelve months of age.

Unless a genetic basis is suspected due to the age, breed, or history of the dog, diagnostics must be performed to rule out infectious, inflammatory, or neoplastic causes.

During the first few months of the disease, symptoms can become progressively more severe. Though the disease can stabilize to some degree with time, episodes of worsening have been reported. As walking becomes extremely difficult towards the end stages of the disease, euthanasia is usually elected.

Talk to your vet about your dog’s spinocerebellar ataxia result so you can plan ongoing care and monitoring.

Watch for early signs such as unsteady or stiff movements, head or limb tremors, or difficulty keeping balance, and contact your vet if you notice any of these.

Keep your dog’s environment calm and consistent. Use rugs or mats to prevent slipping and help them move safely around the home.

As this condition can progress over time, supportive care and a safe, predictable environment can help keep your dog comfortable and engaged with their family.

Late onset spinocerebellar ataxia (loSCA) is an inherited disease first identified in the Parson Russell Terrier. LoSCA has been mapped to a mutation in the CAPN1 gene.

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

CAPN1

Inheritance type

recessive

Clinical category

Neurologic

Citations

1. Forman et al 2013

• Jack Russell Terrier
• Parson Russell Terrier
• Russell Terrier
• Russell-type Terrier