5Walter PA,et al.Renal ultrasonography in healthy dogs[J].American Fournal of Veterinary Research,1987,48:600-607.
6Konde LJ,et al.Sonographic appearance of renal neoplasia in the dog[J].Veterinary Radiology,1985,26:74-81.
7WHITE I R,RUSSEL A J F,WRIGHTL A,et al.Real-time ultrasonicscanninginthe diagnosisofpregnancyand estimationofgestational age incattle. Veterinary Record . 1985
8SCHRICKF N,INSKEEP E K.Determination of early pregnancy in ewesutilizing transrectal ultrasonography. Theriogenology . 1993
9RATTOMH.Ovarian follicular synchronization,ovulation and oocyte de-velopment in llamas andalpacas. . 2005
10RIDLAND M,KNIGHTTW,WYETHTK,et al.Time and incidence offoetal mortality inalpacas. Proc N Z Soc Anim Prod . 1993
