Bunny Hopping Syndrome (BHS1)

The Bunny Hopping Syndrome (BHS1) found in the Weimaraner breed is an autosomal recessive movement disorder due to a neurological developmental defect. In mammals, one half of the brain always supplies the other half of the body. This means that nerves from the left half of the brain innervate the right half of the body and vice versa. For movement control to function correctly, nerve pathways in the spinal cord must only ever run on one side of the body. In dogs with BHS1, this strict order is disrupted and nerve pathways in the spinal cord switch sides. As a result, the dogs cannot target either the left or the right hind leg, but always hop with both legs. Because this gait resembles the hopping of a bunny, the disease is called Bunny Hopping Syndrome. In contrast to Shaking-Puppy-Syndrome in Weimaraner dogs, the gait of puppies affected with BHS1 does not improve according to current knowledge, which usually leads to euthanasia.