Sensory neuropathy in the Border Collie is a severe neurological disorder caused by the degeneration of sensory and, to a lesser extent, motor nerve cells. Clinical signs start between 2 and 7 months of age and include progressive proprioceptive ataxia with intermittent knuckling of the paws, hyperextension of the limbs, and self-mutilation wounds in the distal part of the limbs. Usually, the pelvic limbs are more severely affected than the thoracic limbs. There is decreased or loss of proprioception and nociception in all limbs, and in some cases autonomic signs such as urinary incontinence and, in the later stage, regurgitation has also been reported. Electrophysiological studies show decreased or absent sensory nerve compound action potentials, normal or reduced motor nerve conduction velocities, and normal electromyography in the appendicular muscles.
1 - 2 weeks after arrival of the sample in the lab