Arginine requirements in immature dogs

Labrador Retriever puppies (3 kg) were fed L-amino acid (L-AA) diets, containing the equivalent of 14% protein, to determine dietary argnine requirements for optimal growth and maintenance of normal intermediary metabolism. Growth and food consumption were depressed by decreasing the dietary arginine concentration. Urinary citrate and orotate increased with decreasing dietary arginine. Elevated blood orotate, urea and NH4+-N were detected in arginine deficient dogs. More than 0.56% arginine was required to support optimum growth and prevent abnormal loss of urinary metabolites. The effect of dietary nitrogen concentration (14, 21, or 28% L-AA) on arginine requirements was examined in immature Beagles. All arginine deficient dogs and dogs fed the 28% L-AA with arginine showed signs of emesis, excessive salivation and muscle tremors. Hyperammonemia and hyperglycemia were observed 2 hours after force feeding an L-AA diet devoid of arginine. Only hyperammonemia was observed in the Labrador Retrievers fed the same diet but incorporated into a 2% agar gel. Dietary nitrogen concentration or dietary arginine content dit not significantly influence glucose tolerance response to oral glucose loading. These data show that dietary arginine is required in the immature dog and that the requirement is influenced by dietary nitrogen concentration.