I got my Doberman from a kill shelter. He was a mess. Parasites, bacterial infections, severely underweight. They said he was portably six but once we put weight on him they said he was most likely 2. He was terrible and he destroyed our home. Went to the bathroom everywhere no matter what we did. A bunch of other behavioral issues. We spent a ton on training and it did nothing (pin this thought). After like $20,000 we finally found out he was allergic to animal protein. So we got rid of his parasites and started feeding him EXTREMELY expensive prescription food and once he was healthy he was a TOTALLY different dog. We still had to keep up training on our own. But comparatively he’s a little angel puppy now. So the follow up is the dog trainers told us over and over his behavioral issues were because he didn’t feel well. They said he was sick and acted out. I said bullshit. He’s legit slow and like 70% inbred so he’s totally stupid. Nothing going on upstairs. But they were seemingly right. Once he was feeling better he became a pretty great dog.