Completely unnecessary. The argument that you will see people use is that in the wild the dog would eat the contents of the stomach of their prey. Most of the time, this is just not the case. If you watch a wild kill by wolves or feral dogs, if they even eat the stomach they will tear it open and strew the contents about, then just eat the organ. I have never seen or heard of a wild dog/wolf eat any digestive organ other than the ocaisional stomach. They will leave intestines and all guts to rot.
Does it hurt to feed it? Probably not. Is it necessary? nope.
Does it hurt to feed it? Probably not. Is it necessary? nope.