I've always been a pet guy. My mother manages a Apt Complex and at least once a month she finds strays that need homes. Over the last two years there has been a handful that she'd taken home after being unsuccessful in finding them homes, and two of those dogs I grew attached to so I took ownership of them. Long story short is, I was never aware that their diet was important because as a kid (a semi-poverished family) we only fed our dogs what we had left from the table, it's all we could afford most days. They always were healthy, it seemed.
Well, one of the dogs that I took in was about 2 years old this past April. She was a Bull Mastiff so she was 150lbs. I fed that dog everything leftover from dinners on a weekly. Sometimes this was full servings of Fried Chicken and sometimes steak, but I did this on top of her dogfood for the entirety of her two year life span. Now just imagine everything that you can eat in two years, and you will understand exactly what my dog was eating while she was alive. Yea, she passed away in April. When I found her she was completely paralyzed almost laying in her on feces and a puddle of drool. I immediately thought that my neighbor had poisoned her because she barked a lot at night and, I had other issues with this neighbor. After taking her to the vet she passed away an hour after being there and they too didn't know why but said that she had some type of gastric issue that had possibly flipped her stomach or something.
It was over the next few weeks when I came to realize that I had killed my dog myself and that my neighbor hadn't poisoned her.
In trying to find proof of poisoning via google and matching the things I learned with her symptoms, I actually found my proof that I had killed her over time with a poor poor diet.
I was devastated.
I took in another dog a month before she died that is a small breed, a Havanese specifically.
This dog only gets the proper diet with occasional meats/food dropped on the floor while cooking or eating at the table.
Sorry for the paragraph but I wanted to share my story of just pure ignorance in the hopes that it may save some friends of yours from the same fate in the future.