Have never eaten one but have eaten some strange things and don't mind the idea of cats and dogs. Cow's leg, dog's leg, there's no difference really. Either a person eats animals or they don't.
I wouldn't agree with that exactly. Domesticated animals have individual purpose, which is what we bred them for. Each species has a purpose and a cow's purpose is to be eaten and a dog's purpose is to be a companion. Also, carnivores taste very different from herbivores.
That's speciesism. Who are we to determine what the purpose of other animals is?
You will notice I said "domesticated animals". This means animals that are not found in the wild in their current form and have been bred (genetically modified) into their current form. This modification was done by man to serve man's purpose.
You can also look at it the other way around and say that the species have adapted to new environments through natural selection and in doing so have become extremely successful. The selection being obedience and friendliness (dogs), docility and flavor (cows), and hunting prowess (cats, though this analogy falls apart very quickly as cats are not really domesticated). In doing so they have become three of the most successful species on the planet as none of the three would exist at even 1% of their current numbers in the absence of human influence.