非复杂性水囊瘤，肘部，犬

A 9-year-old mixed-breed dog, in a standing position (A) and sternal recumbency (B), with a small, uncomplicated hygroma that resulted from repetitive trauma while lying on hard surfaces. Note the hairless, callused area of skin where the bony prominence of the elbow contacts the floor when the dog is in sternal recumbency. The hair over the antebrachium has been clipped for an unrelated purpose.