Don't know how far I will get with this but it is worth a try.
When I was a little girl I used to have a picture book (one of those big, thin ones which each page is a picture with the words superimposed on the picture) about a puppy who lived on a farm and all his brothers and sisters teased him. His mother assured him "I love you just the way you are" (possibly not in those words - but I associate the memory of the book with the Billy Joel song!)
It is a lovely book and I'd love to be able to read it to my DS but my mum doesn't have it any more and wasn't sure she remembered the title. I have had a search on amazon but can't find anything.
Any ideas? Oh, if it helps, it would have been first published early 1990s at the latest.