Differential diagnosis of collapse in the dog

COLLAPSE is a challenging clinical sign to investigate in dogs due to the very large number of potential causes. It may occur acutely, episodically or may be the end result of more chronic debilitation associated with one or more of a wide variety of critical illnesses. This article, the first in a series of three, reviews the mechanisms by which acute or episodic collapse may occur in the dog and outlines an approach to the investigation of collapse. Part 2, to be published in the February issue of In Practice, will discuss neuromuscular causes of acute or episodic collapse, while Part 3, to be published in the March issue, will describe cardiovascular and other miscellaneous causes of collapse.