Why did the dogs get mad at Paulsen in "Woodsong"?

You do not specify which incident you are asking about, but I am going to assume that you are referring to what happened in Chapter 7, when "the whole team (was) mad" at the narrator.  In that incident, Paulsen, who ordinarily fostered a good give-and-take relationship with his dogs and understood that "the dogs always (knew) direction...(and often knew) more than the person on the sled", had been "challenging every decision" his dogs had been making because he was afraid of being lost in a storm.  Finally, he "went too far", insisting that the team turn right on a high ridge when they wanted to go left.  Paulsen became infuriated at their refusal to obey, and went so far as to grab his lead dog, Cookie, by the back of her harness and throw her over to the right.  Cookie angrily complied to her master's insistence, and "knowingly" took the team over the edge of a sharp drop".  Fortunately, no one was seriously hurt, but after he had laboriously untangled the dogs and gear from the mess he had created, the dogs let Paulsen know how angry they were at him for not respecting their judgment, avoiding eye contact his best efforts to get them to move on.  Eventually, the narrator was forced to give up and go to sleep as well, berating himself for his stupidity.  After eighteen hours the dogs, figuring their point had been made, were ready to go again (Chapter 7).