You've got complete confusion going on here. Maddie has been dog pack leader for however long (whether you knew it or not) now this little upstart comes along and is getting ideas above their station and she's getting mixed messages from you.

Im assuming Rico is a male, which is easier to deal with.

People often assume a puppy will be bottom of the pack on its arrival, and are surprised when the older dogs are very tolerant, maybe allowing them to take food or toys or just jumping on top of them, seeming that the older dog has been overtaken in status. When the puppy gets older and continues this behaviour, the older dogs will tolerate the behaviour much less.

Now, here is where the mistake has been made. You tell Maddie off when she snaps, this is completely the wrong thing to do. Firstly, you shouldn't be allowing the pup to be pestering her until she gets to the stage where she snaps. She cant be bothered with puppy games.

She may play with the pup but once it gets too far, you need to separate them. Maddie's status needs to be reinforced. You're punishing her for something she's well within her rights to do. If Maddie snaps at the pup, then it will be for a good reason, so you need to take the puppy away from her, praise MADDIE and ignore RICO. I would feed her first and give her privlidges that the others don't. If you start like this, the other problems can then be addressed, i suspect her change in behaviour is in response to the confusion she is feeling right now.

So many people treat their dogs equal or reinforce the wrong dog, leading to big problems.

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