A Retrospective Study of Prognosis of Medical or Surgical Treatment in Dogs with Mitral Regurgitation
The objective was to compare the prognosis of medical treatment and mitral valve plasty (MVP) using cardiopulmonary bypass (CPB) in dogs with mitral valve regurgitation (MR) with pulmonary edema. Fifty-three cases that underwent medical treatment and 16 cases that underwent MVP from April 2005 to June 2007 were entered in the study from 5 animal hospitals. The average age at the time of the initial pulmonary oedema onset was 140 ± 31 months. The average body weight was 5.7 ± 3.5 kg. Cardiac murmur was detected at grade 4.3 ± 0.6 in the mitral valve area. ISACHC classification was II (n = 9), IIIa (n = 30), and IIIb (n = 28). It was cured with diuretics, cardiotonic drugs, and vasodilators at the time of the initial pulmonary edema. Maintenance medical treatments administered were diuretics, cardiotonic drugs, vasodilators, and carvedilol. Forty-one of 53 patients died throughout the survey period, and the mortality was 77%. Mean length of life was 222 ± 214 days. The center survival period was 156 days (1-854 days). Six of 20 MVP cases died during the operation or postoperative hospitalization, and 14 dogs were discharged. The perioperative average age was 123 ± 10 months. The average weight was 5.5 ± 2.2 kg. Two dogs died of a reason other than cardiac disease after discharge. The center survival period was 450 days (233-955 days). With medical treatment alone, MR dogs died from pulmonary edema by an average of 7 month; however, MVP cases survived more than 12 months.