I think this is true, dogs can do okay and even seem better than before on a detox like only fruit, but in time will show ill health...our perfect diet is not theirs. I really wish it were though. I'm vegan and it bothers me a great deal to buy those poor dead souls for my dog, but I do because it's part of her natural diet. Hopefully you're only experimenting for a short time, then he'll be okay...not for long term meal plan though. My dog loves fruit too, by the way...I can't even have it in peace around her, she begs and drools all over me. Nothing like having a dog! They're the best!
~megan