As a mostly vegan I don't want any animal to die to feed another - I realise this is somewhat hard for many to understand, and I have no come back to those who would argue that it is the way nature works- some animals are prey whilst others are the hunters/scavangers.
As PETA explains:
" Some people wonder if it’s “unnatural” to omit meat from the diet of dogs and cats. But to feed them the meat that they would naturally eat, you would have to serve them whole mice or birds or allow them to hunt for themselves, an option that would be unfair to native species of birds and other small animals, since companion cats and dogs have been removed from the food chain and have advantages that free-roaming animals lack. Many vegan dogs and cats enjoy excellent health, and a vegan diet for your companion animal is ethically consistent with animal rights philosophy."
Part of being a guardian to our animals whilst they are here with us is making sure they are given the best of care, to the best of your financial ability.