Vet's Note: Five Essential Nutrients for Senior Heart and Kidney Care
Organ ageing is unavoidable in mammals, and each species faces its own challenges: chronic kidney failure is the commonest problem in older cats, while up to 30% of older dogs have heart problems.
When an animal enters the final third or quarter of its lifespan, we can call it "senior". Ageing is comprehensive: beyond the mobility and sensory changes discussed earlier, deep inside the body changes arrive too, fast or slow.
The ageing heart
Even without disease, the heart can undergo degenerative change with age — fibrosis of heart-muscle cells or thickening of the ventricular wall — affecting its ability to pump blood and even its rhythm (note 1). Pets may tire more easily, have less stamina for exercise, or pant more readily even at rest. Beyond having the vet check your pet, you can look for foods containing specific ingredients that may support cardiovascular function.
Common heart-supporting nutrients
| Coenzyme Q10 | An antioxidant that clears damaging free radicals; in an oxygen-hungry organ like the heart it is thought to resist oxidative DNA damage and ageing. |
| Collagen tripeptide | A form of collagen with a role in heart care. Studies found months of supplementation lowered total blood cholesterol in rabbits, and six months of use helped healthy people prevent and treat cardiovascular problems. |
| Taurine | Found in cardiac muscle, skeletal muscle, the central nervous system and platelets; for cats it is an indispensable essential amino acid. In the heart it helps regulate calcium ions and supports contraction. US vets fed 17 Beagles a low-protein diet for two years: blood taurine fell and one dog developed dilated cardiomyopathy; taurine supplementation markedly improved symptoms — dietary taurine is vital for heart health. |
| Omega-3 fatty acids | Widely known benefits throughout the body; fish oil for dogs with heart disease is medical consensus. Omega-3 helps stabilise heart rate, lowers total cholesterol and blood pressure. In 24 Boxers with heart disease, fish oil significantly improved arrhythmia after six weeks compared with sunflower or flaxseed oil. |
The ageing kidney
The kidney is the other organ that comes up constantly in senior care, and the one most prone to trouble in ageing cats. Renal cortex and the functional units — glomeruli — are lost with age, and blood flow through the kidney declines; in humans, half the glomeruli may be non-functional by age 80.
Urine is the kidney's report card. Often a urine test reveals problems before blood values change — so never skip urinalysis at a health check. Because ageing kidneys regulate body water less well, daily water supply must be adequate. Owners worried about kidneys can start by watching everything about urination: any change in habits, or a sudden change in volume or colour, means see the vet promptly.
Renal cortex / medulla
Finally, owners often worry about protein, sodium and phosphorus levels in food. In healthy animals these need not be a concern: no study shows that lowering protein, sodium or phosphorus early in healthy animals helps preserve kidney function. Any trusted, complete adult diet on the market is fine.
Note 1: the heart is built of heart-muscle cells; with age or disease, inelastic fibrous connective tissue appears between them, restricting the cells' ability to stretch and contract — cardiac fibrosis. A fibrotic heart stretches less and functions below a healthy heart.
❚ Further reading: Do senior pets need their nutrition adjusted? · Cataract or nuclear sclerosis? Sight and hearing changes in senior pets
References
- Grubb TL, Perez Jimenez TE, Pettifer GR. Senior and Geriatric Patients. Veterinary Anesthesia and Analgesia (2015): 988.
- Taylor EJ, Adams C, Neville R. Some nutritional aspects of ageing in dogs and cats. Proc Nutr Soc 1995;54(3):645-656.
- Beynen AC. Coenzyme Q10 in petfood. 2020.
- Tang L, et al. Effects of oral administration of collagen tripeptide on atherosclerosis development in hypercholesterolemic rabbits. J Biosci Bioeng 2015;119(5):558-563.
- Tomosugi N, et al. Effect of Collagen Tripeptide on Atherosclerosis in Healthy Humans. J Atheroscler Thromb. 2017;24(5):530-538.
- Sanderson SL, et al. Effects of dietary fat and L-carnitine on plasma and whole blood taurine concentrations and cardiac function in healthy dogs fed protein-restricted diets. Am J Vet Res 2001;62(10):1616-1623.
- Keene BW, et al. ACVIM consensus guidelines for the diagnosis and treatment of myxomatous mitral valve disease in dogs. J Vet Intern Med 2019;33(3):1127-1140.
- Smith CE, et al. Omega-3 fatty acids in Boxer dogs with arrhythmogenic right ventricular cardiomyopathy. J Vet Intern Med 2007;21(2):265-273.
- Fan D, et al. Cardiac fibroblasts, fibrosis and extracellular matrix remodeling in heart disease. Fibrogenesis Tissue Repair 2012;5(1):15.
