**1. Introduction**

The interest in the efficacy and safety of pet food has been growing worldwide with vegetables, whole grains, fortified active principles, fruits, probiotics, prebiotics, and herbal extracts as the most effective substances available. In addition, the use of antibiotics in the agriculture and intensive farming has also become a relevant concern with consequent potential health risks derived by their entry/accumulation in human food and animal food supply chains.

© 2017 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2017 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
