Saluki Encephalopathy (SSADHD)
What is Saluki Encephalopathy (SSADHD)
Saluki Encephalopathy (SE) is a neurological disorder that is passed down from parents to their offspring. The condition is also known as Canine Succinic Semialdehyde Dehydrogenase Deficiency (SSADHD).
Affected puppies usually show first signs of the disease at the age of 6-10 weeks.
The symptoms are caused by atrophy and degeneration of largest portion of the brain- the Cerebral Cortex. This degeneration leads to holes, also called vacuoles. The vacuoles are the cause of the symptoms and can only be seen on MRI, or found with a necropsy (animal autopsy).
SE is a rare but serious disease, and testing of all dogs is strongly encouraged.
Testing Adult Dogs for SE
Saluki encephalopathy is an inherited disease. Meaning it is passed from the mother and father to the offspring.
SE presents at only 6-10 weeks of age. Puppies can not be tested until 3 weeks of age, and results take 2-4 weeks to return. Minimal testing is available for puppies showing symptoms (additional information regarding symptomatic puppies can be found below).
To prevent SE genetic testing should be performed on all Salukis, especially prior to breeding.
What are the Clinical Signs and Symptoms of SE?
Affected dogs show progressive neurological signs, meaning that as time goes on the signs and symptoms get worse. Neurologic signs can include: - Seizures - Exaggerated gait (hypermetria) - Episodes of vocalization - Difficulty eating/nursing - Reduced Energy (lethargy) - Difficult to wake when sleeping -Absent or reduced eye reflexes (menace reflex) -Loss of limb reflexes (poor proprioception in all four limbs)
Testing can be performed with one of the following labs
Choose the Yellow “Order Test” Button - Dog DNA tests are carried out using cells brushed from your dog's cheeks and gums. - UC Davis will send a test kit to your home, with instructions on how to collect samples, and a pre-paid shipping container. - You are responsible for communicating results to the OFA (directions can be found in the OFA section of this website)
Choose the Embark “Purebred- Breed+Health Test Kit” - Embark will send a test kit to your home, with instructions on how to collect samples, and a pre-paid shipping container. - You are responsible for communicating results to the OFA (directions can be found in the OFA section of this website)
Choose the “Wisdom Panel Premium Test Kit” - Wisdom Panel will send a test kit to your home, with instructions on how to collect samples, and a pre-paid shipping container. - You are responsible for communicating results to the OFA (directions can be found in the OFA section of this website)
Test Results, Interpretation and Breeding Recommendations
Every animal has TWO copies of most genes- one from the mother and one from the father. For a Saluki to have symptoms of SE they must have TWO copies of the SE gene. This means that dogs can have ONE copy and not have any symptoms. A dog who has only ONE copy of SE is called a Carrier. If two carriers are bred, approximately 25% of the puppies are predicted to develop the disease and 50% are Carriers. It is NEVER recommended to breed two carriers. And discouraged to breed a carrier to a non-carrier
Explanation of Possible Test Results:
SE- Is the code for the SSADHD gene N- Is negative 1. SE/SE - Dogs with SE/SE genotype are homozygous for the SE variant found and are expected to develop the disease. 2. N/N - these dogs NOT have any copies of the SE gene and will not develop signs or pass it to their offspring. 3. N/SE - If a Saluki has ONE copy of the gene they will not become sick. These dogs are called Carriers. It is possible for them to pass a copy of the gene to their offspring. If two carriers are mated, approximately 25% of the puppies are predicted to develop the disease and 50% are predicted to be carriers. It is NEVER recommended to breed two carriers. And discouraged to breed a carrier to a non-carrier.
Testing and Treatment of Affected Puppies
At this time, there is minimal testing, outside of genetic screening that can be used to diagnose puppies who have SE. Therefore the focus is largely on genetic testing adult saluki to prevent passing SE to their offspring. Advanced testing is available for puppies that are affected by SE. These include: - An MRI to identify brain lesions in the cerebrum, brainstem and cerebellum. - Blood and Urine tests for gamma-hydroxybutyric (GHB), dihydroxyhexanoic acid (DHHA) and succinic semialdehyde (SSA). However, these tests are merely to confirm that SE is the cause of the clinical signs. Unfortunately there is no treatment for SE. Puppies who have been diagnosed are euthanized as their quality of life declined quickly after their symptoms began.. Therefore genetic testing of all Saluki is the best way to prevent animals from passing on SE.
References and Resources:
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https://vgl.ucdavis.edu/news/new-test-available-saluki-encephalopathy
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Vernau K.M., Struys E., Letko A., Woolard K.D., Aguilar M., Brown E.A., Cissell D.D., Dickinson P.J., Shelton G.D., Broome M.R., et al. A missense variant in ALDH5A1 associated with canine succinic semialdehyde dehydrogenase deficiency (SSADHD) in the Saluki dog. Genes. 2020;11:1033. doi: 10.3390/genes11091033. - DOI - PMC - PubMed - https://www.mdpi.com/2073-4425/11/9/1033