Assessment of indispensable and dispensable amino acids for the immature dog.

A completely purified L-amino acid diet was used to determine the indispensability of leucine, lysine, valine, phenylalanine and arginine in the immature dog. An additional study showed that asparagine, alanine, aspartic acid, cystine, glutamic acid, proline, tyrosine, serine and glycine can be classified as dispensable amino acids for the immature dog. Deletion of these indispensable amino acids resulted in a marked negative nitrogen balance. Increased plasma and urinary urea were also observed when a dietary indispensable amino acid imbalance occurred. Estimates are made for the dietary requirements for leucine, lysine, valine and phenylalanine in the immature dog.