Startle disease

Startle Disease or Hyperekplexia is an inherited neurodegenerative disease that is connected to an impaired transport of the neurotransmitter glycine. Individual mutations in the SLC6A5 gene were found in the breeds Irish Wolfhound, Old English Sheepdog and Spanish Greyhounds, while a variant in the GLRA1 gene was found in Australian Shepherds and Miniature American Shepherds causing Startle disease.
Affected puppies show first symptoms at a very young age, for example already 5-7 days after birth in Irish Wolfhounds. Clinical symptoms are exaggerated extensor rigidity and tremor evoked by handling or in response to either acoustic or tactile stimuli. The puppies are unable to stand or walk and show rigid extended posture in all four limbs. Symptoms lessen when dogs are relaxed or sleeping and increase when the dogs are moving. Additionally, cyanosis can appear while suckling. Affected puppies have to be euthanised.