Episodic Falling Syndrome Testing for Cavalier King Charles

Cavalier King Charles Spaniels suffer uniquely from a genetic disorder called episodic falling syndrome (EFS), causing uncontrolled muscle contractions that lead to rigidity and collapse. It most commonly appears in puppies between 4 and 7 months old and varies in severity from brief episodes to prolonged attacks causing difficulty standing.

This syndrome results from a mutation in the BCAN gene affecting muscle control. While it cannot be cured or prevented after birth, health testing via a simple DNA test can identify whether a dog is clear, a carrier, or affected. Responsible breeders should use this test to avoid breeding two carriers or affected dogs, helping to reduce the prevalence of EFS in the breed.

What is Episodic Falling Syndrome?

EFS is a neurological condition marked by episodes triggered by exercise, excitement, stress, or heat that cause muscle stiffness primarily affecting the hind limbs and back. Some dogs experience rigidity in all limbs. These symptoms can sometimes be confused with epilepsy, so definitive diagnosis through genetic testing is crucial for correct identification and management.

Dogs affected by EFS appear normal between episodes, complicating diagnosis without testing. Medications like Clonazepam or Acetazolamide may help manage symptoms but are not appropriate for every dog due to side effects.

Who is Affected and How Is It Inherited?

This disorder occurs exclusively in the Cavalier King Charles spaniel breed. It is an autosomal recessive genetic condition, meaning a dog must inherit two copies of the mutated gene (one from each parent) to be affected, while carriers inherit only one copy and show no symptoms but can pass the mutation on to offspring.

If two carriers are bred, there is a 25% chance their puppies will be affected, a 50% chance they will be carriers, and a 25% chance they will be clear. Hence, testing breeding dogs before pairing is vital.

How DNA Testing Works

The DNA test for EFS involves collecting a sample from your dog, either a blood sample or a cheek swab, which is then sent to a registered laboratory for analysis. Results classify dogs as:

• Clear: Two normal gene copies; dog will not develop EFS or pass it on.
• Carrier: One normal and one mutated gene; dog will not show symptoms but can pass mutation to about 50% of offspring.
• Affected: Two mutated genes; dog is likely to show symptoms and will pass mutation to all offspring.

Tests are available through accredited UK laboratories listed on The Kennel Club’s website. Testing before breeding helps make informed decisions to prevent producing affected puppies.

Responsible Breeding and Management

Due to the high carrier rate within the breed (over 20% according to surveys), it is essential for breeders to test their dogs to carefully select mating pairs that do not produce affected litters. This limits propagation of the disorder, improving the health and welfare of future generations of Cavaliers.

Owners of affected dogs should work closely with their vet to manage episodes and provide a safe environment. Avoiding known triggers such as excessive excitement, heat, or strenuous exercise can help reduce episode frequency.

Summary and Next Steps

Episodic Falling Syndrome is a serious but manageable condition unique to Cavalier King Charles Spaniels. With available DNA testing linked to the Cavalier King Charles spaniel puppies gene mutation, breeders and owners can take proactive steps to control its spread.

If you own a Cavalier or are considering breeding, ask your vet about testing for episodic falling syndrome to ensure your dog’s health and that of future puppies. Responsible breeding and good management help maintain this beloved breed’s wellbeing for years to come.