Vitamins are quite revitalizing in terms of body physiology and processes. Many enzymes are made of protein bases with vitamin radicals attached. If you want to know the basis of health, you cannot ignore this important aspect. Normally, people ignore the fact that pets are supposed to be given a balanced diet just like we human beings. The problem occurs because most people don't know what to give to dogs since they don't consume vegetables save for avocados. Did you give them supplements? In this regard, a pet owner has to be careful in order not to overdo things by transforming the situation from vitamin deficiency to vitaminosis. The formulation of supplements is generally tailored to factor in human requirements without regard to the fact that animals also require the same. But I might be wrong since there could be veterinary alternatives. I would appreciate any advice to be in the know in this regard since am guilty as charged.