It's amazing how well you think you know someone until one day......
My advise is to take the puppy if the husband offers it, and back away from your friend for a while. What she did, not to mention the condition she's leaving the dog in, is bordering on abuse. She is in the wrong--not you. If she can't take some constructive criticism from someone she's known for so long, then maybe she's not such a great friend after all. This might sound harsh, but in the same situation, I would be more concerned about the puppy than the friendship. She is responsible for her behavior and actions--you don't have to make excuses for her. Your reaction was justified. This goes against what some other people are saying, but it's just my opinion.
Good luck, and please keep us posted!