Startle Disease (Hyperekplexia)

Startle disease or hyperekplexia is an inherited neurodegenerative disease caused by defective neurotransmission of inhibitory glycineric signals. The condition affecting the breed Spanish greyhound is defined by an excessive startle reflex or episodes characterised by hypertonia and apnoea, triggered by touch and/or acoustic stimuli. During such episodes, the termination of breathing may occur, which can be extremely dangerous, due to possible brain damage or even sudden death. Clinical symptoms, that usually begin at birth, include limb rigidity and tremor that is aggravated by unexpected handling or noise, furthermore cyanosis also appears while suckling. Affected dogs are unable to stand or walk unassisted and with assistance, they almost immediately develop extensor rigidity in all limbs. Symptoms usually stop when dogs are relaxed, asleep or under general anaesthesia. As a result of feeding and breathing complications during such startle episodes, neonatal death is also common. In case of survival, affected dogs usually have to be euthanised.

Inheritance: autosomal recessive

Mutation: SLC6A5 gene

Genetic test: The method used for genetic testing is extremely accurate and allows complete differentiation between affected animals, carriers and healthy dogs. DNA testing can be done at any age.