Feline Spinal Muscular Atrophy (SMA): An In-Depth Explanation

Feline Spinal Muscular Atrophy (SMA) is a hereditary neuromuscular disorder that affects cats. It is a genetic condition characterized by the degeneration of motor neurons in the spinal cord, leading to progressive muscle weakness and atrophy. SMA is caused by a mutation in the survival motor neuron 1 (SMN1) gene, which is essential for the survival of motor neurons.


SMA in cats is inherited in an autosomal recessive manner. This means that for a cat to develop SMA, it must inherit two copies of the mutated SMN1 gene, one from each parent. Cats that inherit only one copy of the mutated gene are carriers, meaning they don't show symptoms but can pass on the mutation to their offspring. When two carriers are bred, there's a 25% chance of producing an affected (SMA-affected) kitten, a 50% chance of producing a carrier kitten, and a 25% chance of producing an unaffected kitten.

Signs and Symptoms: 

The onset of SMA symptoms in cats typically occurs within the first few months of life, often becoming noticeable around 3 to 4 months of age. The severity of the disease can vary, but common signs and symptoms include:

Diagnosis: Diagnosing SMA involves a combination of clinical signs, genetic testing, and ruling out other potential causes of similar symptoms. Genetic testing can confirm whether a cat carries the mutated SMN1 gene or is affected by the disorder.

Treatment Options 

Treatment mainly focuses on managing the symptoms and improving the affected cat's quality of life. Some approaches that might be considered include:

It's essential to consult with a veterinarian who has experience with neurological conditions in cats to determine the best course of action for managing a cat with SMA.

What types of SMA genetic markers are there?

There isn't a wide array of detailed genetic markers identified specifically for feline SMA, unlike some other genetic disorders in animals. The primary genetic marker associated with feline SMA is the mutation in the survival motor neuron 1 (SMN1) gene. This gene is responsible for producing survival motor neuron protein, which is critical for the survival and function of motor neurons in the spinal cord.

The specific genetic mutation involved in feline SMA is a deletion in the SMN1 gene. This deletion leads to a deficiency or absence of functional survival motor neuron protein, resulting in the degeneration of motor neurons and the development of spinal muscular atrophy in affected cats.

Due to the relatively limited research on feline SMA genetics compared to more common genetic diseases, there might not be an extensive set of markers or variations associated with the condition. Most of the diagnostic genetic testing for feline SMA revolves around identifying this specific deletion in the SMN1 gene.