What is Episodic falling syndrome in dogs?

Episodic Falling Syndrome (EFS) in dogs is a neurological condition causing the muscle tone to increase suddenly in the dog to the point where the dog freezes up and cannot relax its muscles, resulting in the dog falling over. Dogs affected by Episodic falling syndrome which is an exercise-induced-hypertonicity disorder can start to have episodes from 14 weeks of age with most dogs begin being affected before they are 5 months of age. These episodes are often in response to frustration, exercise or excitement. Severely affected dogs can have episodes for no apparent reason. This condition is found in many breeds but is extremely prevalent in Cavalier King Charles Spaniels and was once commonly known as “Cavalier Falling Syndrome”.

Genetics of Episodic Falling Syndrome

This is an inherited disorder that has an autosomal recessive pattern of inheritance meaning that 2 healthy parents carrying the disease can have affected offspring even if they themselves are not affected. The gene that is responsible for this condition is the BCAN gene that has a rearrangement mutation. Dogs that are either carriers of the mutation, or worse, affected by the condition, should not be bred to either carrier or affected dogs. Having one parent clear of the mutated BCAN gene will prevent any of the puppies in the litter from being affected by Episodic Falling Syndrome (EFS).

What is the severity of Episodic Falling Syndrome?

Episodic Falling Syndrome is considered to have a low to medium level of severity as the condition is not normally considered to be painful to the dog, nor does it have a high degree of morbidity. Affected dogs tend to learn to cope with the episodes better as they get older and have more experience with them. Episodic Falling Syndrome does not seem to affect the temperament of affected dogs.

What are the symptoms of Episodic Falling Syndrome in dogs?

Symptoms of Episodic Falling Syndrome may include one or a number of the following : Freezing momentarily, attempting to rise only to fall, freezing or walking with the head down and to one side, bunny-hopping gait, stiffness in the back legs, temporary loss of control in the hind legs, lack of coordination in the rear or front legs, drooling and spasms. Affected dogs will look like unaffected dogs in between episodes.

Diagnosis of Episodic Falling Syndrome

A definitive diagnosis of Episodic Falling Syndrome in dogs can be difficult as the symptoms are often very similar to other neurological conditions if only clinical methods are used. Thankfully, a DNA Disease Screen developed by the Animal Health Trust gives a definitive answer as to the genetic status of a tested individual so will provide a veterinarian with conclusive result.

Treatment of dogs with Episodic Falling Syndrome

Treatment of Episodic Falling Syndrome in dogs is limited and most owners of affected dogs tend to make sure the dog is not in situations where the dog would be in danger if an episode occurred. This means that the dogs would be restricted from being off-lead near roads or on unstable terrain such as steep hills. Dogs affected by Episodic Falling Syndrome will live a relatively normal life outside of the episodes and have an average lifespan relative to their breed.

References

Frequency of two disease-associated mutations in Cavalier King Charles Spaniels. Animal Health Trust. 2012
Gill JL, Tsai KL, Krey C, Noorai RE, Vanbellinghen JF, Garosi LS, Shelton GD, Clark LA, Harvey RJ. A canine BCAN microdeletion associated with episodic falling syndrome. Neurobiol Dis. 2012 Jan; 45(1):130-6
Herrtage ME, Palmer AC. Episodic falling in the cavalier King Charles spaniel. Vet Rec. 1983 May 7; 112(19):458-9.
Slatter, Douglas H. Textbook of Small Animal Surgery (3rd ed.). W.B. Saunders Company