Episodic falling syndrome health testing for the Cavalier King Charles spaniel

Episodic falling syndrome is a genetic disorder that is unique to the Cavalier King Charles spaniel dog breed, which leads to a tendency to develop uncontrolled muscle contractions of the legs and body, causing rigidity of the back legs and bending of the spine. Some dogs may suffer from rigidity in all four legs, which can lead to collapse and difficulty recovering their footing, hence the name.

Exactly how badly the condition affects any given dog can vary, with attacks passing in just a few seconds for some dogs, but lasting significantly longer in others.

The condition cannot be prevented or reversed, although a slightly milder variant of the condition was discovered in 2011 that in some cases begin to stabilise as the dog gets older, having a very small impact on them for the remainder of their lives.

Because the condition is hereditary and widely spread within the breed’s gene pool-in fact, over 20% of Cavalier King Charles spaniels were found to be carriers of the condition in a 2012 survey-owners of Cavvies that may wish to use their dogs for breeding are strongly advised to have them tested for the markers of the condition first, in order to avoid passing the condition on to further, subsequent generations of dogs of the breed.

In this article, we will look at episodic falling syndrome in Cavalier King Charles spaniels in more detail, including how and why the test for the condition is performed.

More about episodic falling syndrome

Episodic falling syndrome is a neurological condition that is often confused with other health conditions that present with similar symptoms, such as epilepsy. This means that testing for the condition is important not only to ensure that affected dogs do not go on to breed, but also so that your dog’s condition can be definitively and correctly diagnosed.

Exactly how the symptoms of the condition present and how badly it affects dogs will vary from case to case, but all of the symptoms associated with the condition present when the muscles in various parts of the dog’s bodies become tense and unable to relax normally. Stress, heat, exercise and excitement can all trigger an episode of the condition, all of which lead to the dog losing their coordination and ability to control their own muscles, which usually leads to collapse, although not in all cases.

The condition cannot be cured (nor prevented in dogs that have the genetic markers that cause the condition), but in some cases, it can be managed with medications such as Clonazepam and Acetazolamide. However, these medications are not suitable for all dogs, due to the potential side effects that they can produce, which can in some cases be as bad as the condition itself.

What sort of dogs are affected by the condition?

The Cavalier King Charles spaniel is the only purebred dog breed that is afflicted by the condition, and it is very prevalent within the gene pool of the breed.

Dogs that will be affected by the condition usually become symptomatic well before they reach the age of one, with four to seven months old being the average. Males and females are equally likely to be affected by the condition, and even dogs that are themselves healthy and not suffering from the condition may be carriers for it, and so able to pass it on to their own offspring.

How does the heredity of the condition work?

Episodic falling syndrome in dogs is an autosomal recessive condition, meaning that in order for a dog to develop the condition themselves and/or become a carrier for it, they must have inherited a certain combination of faulty genes from their parents.

If the two parent dogs are both clear of the condition, their own offspring will be clear too. If a dog inherits one copy of the gene mutation for episodic falling syndrome but not two, there is a 50% chance for each of their own offspring to be clear or carriers respectively.

Dogs that inherit two copies of the gene mutation will be affected with the condition themselves.

Testing for episodic falling syndrome

Because the gene mutation that causes episodic falling syndrome in the Cavalier King Charles spaniel is so widely spread throughout the breed, dog owners who wish to breed from their dog are strongly advised to have them DNA tested prior to breeding, so that an informed decision can be made about the viability of any breeding pair.

The test itself involves asking your vet to take a DNA sample from your dog (such as a blood sample or a swab of the skin cells from the inside of your dog’s cheek) which you then need to send away to one of the registered laboratories that can test for the condition.

A list of laboratories that can perform the test can be found on The Kennel Club’s website.