Tail chasing in a dog with brain atrophy: A case report

A 2-year-old male mixed breed sheepdog was presented with a history of worsening recurrent tail chasing (TC) and biting by 2 months of age. Physical examination and blood tests showed no health problems, except for mild leukocytosis. Behavior analysis excluded the presence of other compulsive behaviors, but aggressive behavior during TC was reported. Neurological examination showed aggressive behavior in a dog that was otherwise quiet until few months before the consultation. A forebrain disorder such as a congenital or a degenerative disease could not be ruled out. In vivo computed tomography brain scan revealed widened sulci and symmetrical lateral ventricular enlargement, which were associated with cerebral atrophy with acquisition of contrast enhancement. A diagnosis of brain atrophy probably due to a degenerative disease was made. After 5 days, the dog was euthanized following the owner's request due to deteriorating condition. In dogs showing repetitive and potentially compulsive disorders, veterinarians should be aware that a structural disorder as a brain atrophy should be included in differentials.