Looking for poem about forsaking elderly dog

Many years ago I read an essay or poem about a young couple having a puppy that was so important to them and then as the years went by and they had children, the elderly dog was forgotten and its heart broken. It was written as the dog talking about not understanding why their master didn't love them any more, in a manner to inspire someone not to do this to their dog. I printed it and saved it but now I cannot find it anywhere.

Have I described this well enough that anyone could direct me to this essay on the internet? I need it very badly because someone I've been close to is breaking my heart the way they are treating their elderly dog who once was their pride and joy.

Thanks.