Vitamin status of the healthy dog

The interest in nutrition and the effect it has on health and disease has gained increasing interest during the last years. Still remarkably little is known about some of the basic concepts concerning vitamin metabolism in dogs. No reference values have been set for the concentration of vitamins in the dog blood or tissues. The requirements for the daily intake of nutrients have been established, but the studies on which they are based on are not at all as comprehensive as might be expected. The aim of this review is to map what is scientifically known about the vitamin metabolism of healthy dogs, what kind of values have been collected from healthy dogs and to compose guide lines for future reference ranges. The compilation of 35 vitamin studies demonstrates that while a fairly decent amount of studies concerning vitamins in dog blood have been made, their results are not comparable because of the differing protocols and because of missing reference values. To gain more insight on the vitamin concentrations of healthy dog blood and measuring protocols, a pilot study was performed. We measured the concentrations of vitamins A, D and E from 13 healthy Finnish dogs. Two medium-sized breeds were chosen: Rough Collies and Flat-coated Retrievers. All dogs were healthy females of the age 3 – 5 years. The results from our pilot study varied to a degree from other studies concerning different vitamins. To analyse how significant the differences actually are, raw data from the other studies would be needed. The findings of this review challenge the present knowledge about vitamins for dogs in nutrition. It shows the need for new studies on the vitamin metabolism of dogs. From there measuring protocols could be developed and reference values established. Finally improved nutritional guidelines, applications to the every day practise and individual vitamin plans could be formed. Research in veterinary nutrition could lead to a true understanding of the role of vitamins and nutrients in preventing and treating diseases both in veterinary and human medicine.