Methods: 20 healthy dogs were divided at random into three groups: assistant group(group A,n=9),heart failure group(group B,n=9) and control group(group C,n=2).

• 方法:20只实验犬随机分为3组:辅助组(A组,n=9)、心衰组(B组,n=9)和对照组(C组,n=2)。