Cognitive dysfunction and owner-directed aggression in a 10-year-old neutered golden retriever: A case report

A 10-year-old, 38.5 kg, male neutered golden retriever was evaluated for a 2-year history of growling, baring teeth, and biting his owners. The dog also displayed disorientation, increased vocalization, altered interactions with the female owner, anxiety, and nighttime restlessness. A primary diagnosis of cognitive dysfunction syndrome and concurrent diagnosis of owner-directed aggression related to altered cognition or awareness, pain/discomfort, and impulse control/conflict was made based on the dog’s age, behavioral signs, and exclusion of medical causes. The owners were provided with a treatment plan that included environmental and safety management, reward-based behavior modification, and an antioxidant-rich diet. After the addition of a selective serotonin reuptake inhibitor (fluoxetine) and a serotonin antagonist and reuptake inhibitor (trazodone), the dog’s clinical signs were significantly improved within six months and sustained during a 2-year follow-up period.