Signalment: 7-year-old, female spayed Bull Terrier mix.

Primary Complaint: Generalized anxiety worsening over the last 2 years with severe thunderstorm phobia.

History: The dog was born in an animal rescue shelter and was adopted as an 8-week-old puppy by the first owner. The animal was crated most of the day throughout the first year of life with no more than 30 minutes of exercise per day. The current owner adopted the dog when she was 1 year of age and noted she was severely anxious all day, every day. After one year of acclimation, the dog was started on daily trazodone (50 mg BID), which successfully managed the dog’s anxiety from 2 to 5 years of age. Two years prior to presentation, at the age of 5 years, the anxiety worsened, especially during thunderstorms. The trazodone dose was increased to 100 mg BID and an additional 50 mg two hours prior to thunderstorms was given. This dose escalation resulted in a 50% improvement of the anxiety. Six months later, the patient underwent general anesthesia for a prophylactic dental cleaning and experienced asystole during the procedure. With emergency intervention, the patient’s heart returned to a normal sinus rhythm which was followed by an uneventful recovery. Other than the anesthetic adverse event, there were no previous major illnesses throughout life.