Cerebral small vessel disease in a six-month-old Rottweiler with severe subaortic stenosis

A six-month-old, 23.5-kg female Rottweiler with severe subaortic stenosis (SAS) was referred for cardiological management due to exercise intolerance. Transthoracic echocardiography revealed severe SAS with a pressure gradient of 130 mmHg. A combined cutting balloon and high-pressure balloon dilation was performed. Postoperatively, the dog developed neurological signs, including depression, absent menace reaction, and reduced facial sensation. Despite further treatment, the clinical signs worsened with blindness and inability to maintain spontaneous breathing before becoming comatose, after which the owner elected for euthanasia. Necropsy confirmed severe SAS and revealed chronic cerebrocortical necrosis in the brain, with multiple intraparenchymal hemorrhages, vessel congestion, and gliosis. These findings indicated chronic ischemic damage such as that highlighted in cerebral small vessel disease described in humans. This case suggests a potential link between severe SAS and cerebral small vessel disease, similar to findings reported in human patients with severe aortic stenosis. Further research is necessary to explore the connection between SAS in dogs and cerebral perfusion alterations and to determine whether the intervention triggered the symptoms or if they arose independently.