Juvenile Myoclonic Epilepsy (JME) Testing in Rhodesian Ridgebacks

Rhodesian ridgebacks are known to be particularly at risk of juvenile myoclonic epilepsy (JME), a hereditary neurological disorder that manifests typically in young dogs around six months old. This type of epilepsy differs from other epilepsy forms because it presents early with frequent seizures, mainly myoclonic seizures—sudden, involuntary muscle jerks or twitches—often occurring during rest or sleep.

Unlike many other types of epilepsy that appear in middle age, JME develops early and may significantly impact quality of life for affected dogs.

What is Juvenile Myoclonic Epilepsy?

JME is a genetic epilepsy condition in dogs characterised by brief muscle spasms and jerky, uncontrolled movements that can happen unpredictably. These seizures tend to occur mostly when the dog is resting or sleeping but can also be triggered by bright light or other stimuli. Frequent seizures—sometimes over 100 per day—are common in dogs with JME, requiring close supervision to ensure their safety during attacks.

Which Dogs Are at Risk?

This condition is especially found in Rhodesian ridgebacks, with studies indicating up to 15% may carry the gene responsible for JME. Symptoms generally appear between a few weeks and 18 months, with two-year-old dogs without symptoms considered unlikely to be affected but possibly carriers.

How is JME Inherited?

JME follows an autosomal recessive inheritance pattern. This means a dog must inherit two copies of the faulty gene—one from each parent—to be affected. Dogs with one copy are carriers and typically healthy but can pass the gene on to offspring. Understanding the genetics helps breeders make informed choices to avoid producing affected puppies.

• Two clear parents: All puppies clear of the mutation.
• Two affected parents: All puppies affected.
• Two carriers: Expected 25% affected, 50% carriers, 25% clear puppies.
• One clear and one affected parent: All puppies are carriers but not affected.
• One carrier and one clear parent: Puppies are 50% carriers, 50% clear.
• One carrier and one affected parent: Puppies are 50% affected, 50% carriers.

Genetic Testing for JME

The only way to reliably detect a dog's genetic status is through a DNA test. Your vet can collect a blood sample or buccal swab, which is sent to a specialised laboratory. Results typically return in a few days, classifying the dog as clear, carrier, or affected.

This test is crucial for breeders to prevent breeding affected dogs and manage carrier matings responsibly, thereby reducing the prevalence of JME in the breed.

Buying and Breeding Healthy Rhodesian Ridgebacks

Responsible breeders will test their breeding stock for JME and provide evidence of these health clearances. Avoid breeders who do not perform such tests, as breeding affected or carrier dogs without knowledge perpetuates the condition.

Breeding a carrier with a clear dog is accepted to maintain genetic diversity but requires follow-up testing of offspring if they are to be future breeding stock. Prospective owners should always seek puppies from health-tested parents to ensure their new dog has the best chance of living a healthy life.

Genetic testing and awareness empower you to make informed decisions, protecting your future dog's health and supporting the welfare of the Rhodesian ridgeback breed as a whole.