I'm pretty sure that depends on what organization they are fighting with and the specific rules. It's not hard to find articles about controversy when a referee stops a fight[1]. In the linked case, there was no count, nor even a knockdown. Obviously there are cases, at least in some boxing organizations, in which a ref can stop a fight without a full count.

1: http://www.badlefthook.com/2014/3/9/5486930/canelo-vs-angulo...