I am truly sorry for what you're going through with your dog. It is so hard. I, myself am going through something similar. My almost 14 yr. old Lab has liver failure and has had several seizures as a result. It's terribly upsetting to watch. When her quality of life is bad enough, that it outweighs her enjoyment of life, I too will have to make that heart wrenching decision to spare her further suffering.
I often wonder if the anti-inflamatory I gave her for her arthritis contributed to her liver problem. The vet doesn't think so, because she didn't have much, but it's just a feeling I have and with that feeling comes guilt.
I don't think it was the food that caused anything in your dog. I had dogs live to be 18 and 16 who were raised on Purina Dog Chow. All this about premium food has come up more recently. I do feed a better food now, but honestly, I doubt that has anything to do with your dog's problem.
I have four dogs and one is a Dobmerman Pinscher. They have more than their fair share of health issues. One of those is cancer. It is in their lines, in all the lines. So in most cases, this can be genetics and nothing else. They also are prone to cardiomyopathy. Do you think that everyone whose dog gets these things blames themselves? Of course not. And you shouldn't let anyone's cruel, wicked remarks influence you.
Give your dog the best love and fun you can and when and if your dog gets too unhappy or sick, kiss him good bye and you'll see him in your memories. We all have to go through this. My thoughts are with you.
I think it's atrocious what was said to you and I am suprised that the forum owner would allow this kind of treatment to anyone. But that's not my business. I can choose whether or not I want to visit such a forum.
Carrie