Vitamin B5 (pantothenic acid) is critical for animal health because it is involved in a vast number of chemical reactions within the body.  Besides turning fats, proteins, and carbohydrates into energy, vitamin B5 interacts with other vitamins to perform necessary functions.  For example, it works with vitamin C to maintain the health of the adrenal glands.
Pantothenic acid plays in important role in the immune system, helping it to remove toxic substances from the body.  This vitamin also assists in the production of hormones, the transmission of signals along the nerves, and the creation of blood cells.  Not surprisingly, vitamin B5 is important for proper reproduction and growth.