Centronuclear Myopathy in Dogs

Category: Muscle
Inheritance: Autosomal recessive
Breeds documented: 1
Published sources: 3

Overview

Centronuclear myopathies are inherited muscle disorders named for the unusually central position of nuclei, the control centers inside muscle cells. Different genetic forms can cause weakness, muscle loss and difficulty walking. Some forms appear during puppyhood, while others can start later. Their course varies too: some affected dogs stabilize, while others develop worsening disability.

Signs to watch for

Reduced muscle strength
Tiring quickly during activity
Short, stiff steps or hopping with the back legs
Muscles becoming smaller
A hoarse bark with myotubular myopathy, an inherited muscle disorder

Onset varies by form; one Labrador form typically appears at 2 to 5 months.

When to get help Book a vet visit when you notice muscle weakness, an unusual walk or reduced stamina.

Diagnosis and tests

A vet assesses muscle strength and movement, then chooses tests suited to the suspected form. Genetic testing can confirm certain forms, including the Labrador variant tested by UC Davis. A muscle biopsy, which examines a small tissue sample, can also confirm the disease. Tests recording muscle electrical activity may provide further evidence.

Breeds with documented risk

1 breed

By breed size

1 Large

Labrador RetrieverLarge · Sporting Group

Inheritance

This condition has more than one known form, and different breeds inherit it in different ways. The sources list the form found in each breed.

Autosomal recessive
Labrador Retriever
A dog is affected only if it inherits two copies of the gene variant, one from each parent. A dog with one copy is a carrier: usually healthy, but able to pass the variant on. When two carriers are bred, on average one puppy in four is affected. A DNA test can tell clear, carrier and at-risk dogs apart.
As stated by OMIA
Autosomal dominant
Border Collie
One copy of the variant, from either parent, is enough to put a dog at risk. On average, an affected dog passes the variant to half of its puppies. Males and females are affected equally.
As stated by OMIA
X-linked recessive
Labrador Retriever
The variant sits on the X chromosome. Males have one X, so one copy is enough to affect them. Females have two, so they are usually healthy carriers. Most affected dogs are male, and a carrier mother passes the variant to about half of her sons.
As stated by UC Davis VGL

We've gathered what published sources say about this condition, so you can talk it through with your vet. It isn't veterinary advice: you and your vet know your dog best.