What is commonly heard during a physical examination of a dog's abdomen indicating active intestinal movement?

Borborygmi refers to the sounds produced by the movement of gas and fluid within the intestines. These sounds are often described as gurgling or rumbling noises and are indicative of active intestinal motility. When veterinarians perform a physical examination of a dog's abdomen, they listen for borborygmi to assess gastrointestinal function. The presence of these sounds typically suggests that the intestines are functioning normally and are effectively moving contents through the digestive system.

In contrast, nasal stridor is a breathing sound associated with issues in the upper respiratory tract and does not relate to intestinal movement. Tachycardia and bradycardia refer to an increased or decreased heart rate, respectively, and are more relevant to cardiac function than to gastrointestinal activity. Therefore, borborygmi is the correct answer as it specifically indicates active intestinal movement within the abdomen during a physical exam.