I know what the Bible says about what food may and may not be eaten. I can fully understand why we cannot eat scavengers, meat eaters and excrement eaters, this includes pigs and all shell fish. I do not understand why we cannot eat horse, zebra, ostrich or rabbit. Please can you shed some light on this.

The Torah does not mention "scavengers" etc. as identifying marks of those animals, fish or birds which cannot be eaten. Your question reflects the difficulty in the explanations that you accept as the basis for the Torah prohibition. As Maimonides writes in his introduction to Tractate Avot , these restrictions are included among those miztvot that are not readily understandable through common sense. Maharal points out in Tiferet Yisrael that there is an absolute spiritual truth that underlies these mitzvot, rather than just a medicinal or practical rationale.