My 4 month old neutered puppy urinated on my back. Not a tiny amount like marking, but a large amount (I know, stop laughing). What could cause this?:confused:

He is exhibiting dominant behavior. He is marking his territory and letting everyone know that you belong to him. Without knowing you or your situation, it appears that he believes he is the one in control, not you. You need to train yourself to be the leader, the alpha of the "pack." Labman has some very good information and training techniques that he recommends that will be of great help to you. I will not steal his information and claim it as mine, LOL. I am positive that he will stop by at some point today and give you the help that you need. We aren't always online when people need help immediately, so please be patient.

The key to most behavior problems is approaching things using the dog's natural instincts. Dogs see all the people and dogs in the household as a pack with each having their own rank in the pack and a top dog. Life is much easier if the 2 legged pack members outrank the 4 legged ones. You can learn to play the role of top dog by reading some books or going to a good obedience class. A good obedience class or book is about you being top dog, not about rewarding standard commands with a treat. Start at Raising Your Dog with the Monks of New Skete For more on being top dog, see Establishing and Keeping Alpha Position, Letting your dog know you are the boss

The current trend is to neutering as early as 4 months. Might be a good time to ask your vet what he thinks.