Honestly, I don't understand why people think the ponies would be shocked if Spike decided to eat meat. Fluttershy has plenty of carnivorous pets and has fed some of her critters meat in the show. (in the form of fish and worms)
Spike isn't 100% vegetarian in the show either. (he ate worms and liked them) Besides, he's got fangs and he has them for a reason. Gems and veggies aren't that reason, he has molars for those.
Just look at him. You'd have to be evil to deny him this treat.
For those who are wondering why it looks different from my other work, this is actually my own style.