ABSTRACT
Animals are live and sensitive creatures; although their general appearance re¨ects their health and welfare, it is not so easy to de¤ne this concept in such a way that it can be scienti¤cally assessed. Ÿe measurements of skin color variation in stressful situations would be an indicator because the color of the skin may oscillate and become pale yellow in the living of stressful situations, a condition generated by psychological reactions, neurohumoral mechanisms, and physiological responses to symptoms of stress such as fear and fright. Stress has some common symptoms in humans and animals (Conceição 2008, 2010).
