Unlike fat and carbohydrate, excess amino acids are not stored by the body for future use.Īll companion animals have the ability to metabolize excess protein. Conversely, if the animal is in zero or positive energy balance (i.e., consuming adequate or excess energy than it is expending, respectively), the excess protein will be deposited as fat and the nitrogen will be excreted in the urine.
If the animal is in negative energy balance, the excess protein will be used as an energy source. When protein in excess of needs is consumed, there are two possible uses for the additional protein (amino acids). Melody Foess Raasch DVM, in Canine and Feline Nutrition (Third Edition), 2011 PROTEIN EXCESS IN DOGSAND CATSĪs discussed previously, there is some evidence suggesting that it may be beneficial to feed animals levels of protein that are higher than the minimum level necessary to maintain nitrogen equilibrium, and that whole-body protein turnover provides a better estimate of an animal’s maintenance protein needs. For the average animal, these changes are insidious, may not be obvious at necropsy, and may never lead to renal failure however, current urinary or systemic disease can accelerate the process. Functionally, with age, glomerular filtration rates slowly decline, hypertension increases, urine concentrating ability declines, and vascular resistance increases. Concurrently, progressive decreased kidney weight and volume and reduced cortical thickness occur. Those changes may be seen incidentally in histologic sections of aged domestic animals, especially dogs and cats. After maturity, there begins a slow steady reduction in the number of viable glomeruli with accompanying glomerulosclerosis, atrophic changes in tubules, increased interstitial fibrosis, basement membrane thickening, and reduced renal function. Confer, in Pathologic Basis of Veterinary Disease (Sixth Edition), 2017 Aging of the KidneyĪs animals age, they have increased risk of kidney disease however, aging alone may not cause spontaneous kidney disease, but aging is associated with anatomic and physiologic changes in renal structure, function, and regenerative capacity.