Have you ever noticed that different languages use different words to mimic or describe animal sounds? A professor in Adelaide has made a compilation of the sounds for animal sounds in different languages - you can find it here, complete with some common commands as well.
I can only speak for the German bits, where there's actually more sounds that can be used; at least I have heard other sounds as well in German language. In some cases, there's also a difference between mimicking the sound and describing it, and the table seems to mix both of them in some cases. I find it very interesting, though, and quite amusing to learn that French pigs go "groin groin"!