Succinic Semialdehyde Dehydrogenase Deficiency (Discovered in the Saluki)

Succinic Semialdehyde Dehydrogenase Deficiency, formerly known as central nervous system status spongiosus in Saluki dogs (SSSD), is caused by deficiency of succinic semialdehyde dehydrogenase (SSADH) enzyme critical in the metabolism of gamma-aminobutyric acid (GABA) neurotransmitter. The enzyme deficiency leads to cerebral cortical atrophy with vacuolation (status spongiosus) predominantly affecting gray matter structures in the brain. SSADHD is characterized by generalized or focal epileptic seizures, difficulty being aroused from sleep, and altered behaviors, such as episodes of vocalization. While a physical exam can appear normal in affected dogs, a neurologic exam may reveal a mild generalized ataxia with thoracic limb hypermetria (overreaching steps), bilaterally absent menace reflex, and delayed proprioceptive positioning in all limbs. The initial neurological signs are usually seen in affected puppies between the ages of 6 to 10 weeks.

There is no effective treatment available for SSADH deficiency. Anti-seizure medications may help control seizures in affected dogs but will not address the underlying disorder. Upon initial observation of clinical signs, affected dogs should be closely monitored to assess welfare. Due to the early onset and severe nature of clinical signs, the prognosis is considered poor for affected puppies and humane euthanasia is often considered by 9 months of age.

There are many responsibilities to consider when breeding dogs. Regardless of test results it is important that your dog is in good general health and that you are in a position to care for the puppies if new responsible owners are not found. For first time or novice breeders, advice can be found at most kennel club websites.

This disorder is autosomal recessive, meaning two copies of the variant are needed for a dog to be at an elevated risk for being diagnosed with the condition. A carrier dog with one copy of the Succinic Semialdehyde Dehydrogenase Deficiency (Discovered in the Saluki) variant can be safely bred with a clear dog with no copies of the Succinic Semialdehyde Dehydrogenase Deficiency (Discovered in the Saluki) variant. About half of the puppies will have one copy (carriers) and half will have no copies of the variant. Puppies in a litter which is expected to contain carriers should be tested prior to breeding. Carrier to carrier matings are not advised as the resulting litter may contain affected puppies. Please note: It is possible that disorder signs similar to the ones associated with this Succinic Semialdehyde Dehydrogenase Deficiency variant could develop due to a different genetic or clinical cause.