Optimal timing for mitral valve repair surgery for asymptomatic patients with mitral valve prolapse and severe mitral valve regurgitation has become a topic of study in both humans and dogs. The results of these investigations have led to improvements in perioperative management, including anesthesia and cardiopulmonary bypass, and the skill of surgeons. Mitral valve repair has been established as one of gold standard surgical method for mitral valve disease. Surgical procedures have advanced and surgical indications have expanded with the development of the artificial mitral annulus ring and replacement of the chordae tendineae using artificial materials.High survival rates can be expected in dogs if the appropriate surgery is performed. As the number of mitral valve repair procedures increases, it will be necessary to evaluate the progression of degenerative lesions and the longterm durability of the procedures. Furthermore, as mitral valve repair becomes more common and accessible in more facilities, high levels of expertise and proficiency among veterinary care practitioners will be required.

A 14-year-old castrated male Shih Tzu weighing 5.4 kg presented for refractory pulmonary edema evaluation. The dog was diagnosed with myxomatous mitral valve disease, ACVIM guidelines stage D with an intermediate probability of pulmonary hypertension. Four months after the initial visit, the dog underwent surgical mitral valve repair. The dog recovered well from surgery and was discharged 4 days after the procedure without complications. One month after surgery, the dog presented for ascites and multiple episodes of syncope. The dog was diagnosed with right sided congestive heart failure due to pulmonary hypertension and died 69 days after mitral valve repair from apparent respiratory distress despite aggressive medical treatment, including sildenafil, furosemide, and pimobendan. While the cause of this patientʼs pulmonary hypertension remains unknown, pulmonary thromboembolism was suspected based on blood coagulation tests and clinical course. This case suggests that increased age and preoperative tricuspid regurgitation severity might be associated with postoperative pulmonary hypertension.

短頭種気道症候群とはブルドッグ、ペキニーズ、パグ、ボクサー、狆などを代表犬種とする、外鼻孔狭窄、軟口蓋過長症、気管低形成、反転喉頭小嚢、鼻道の解剖学的構造による上気道閉塞を示す症候群のことをいう。臨床徴候としてはいびき、呼吸困難、咳、失神があげられ、そのほかに胸腔内圧の変化に伴い肺水腫や洞性不整脈が認められるとされている。今回、我々は一次診療施設から心原性肺水腫を疑い紹介来院した症例を短頭種気道症候群による陰圧性肺水腫と診断し、その症例が快方に向かったためにこれを報告する。