It’s inevitable that our much-loved canine companions will age and with their advancing years comes a waning of their physical and mental capabilities — thought to be due to an accumulation of oxidative damage to cells of the body. It’s important to understand, however, what oxidative damage is and how antioxidants can have a positive effect on their body, so we’ve put together a list of what antioxidants and other essential nutrients can do this.
So, what is oxidative damage?
First of all, normal metabolism results in the production of molecules known as oxidants. These molecules can damage cell membranes and other structures, but enzymes, such as superoxide dismutase, break down these oxides and minimise the damage they cause. Mice, for instance, that lack superoxide dismutase can suffer from heart disease and early death, as well as increased age-related loss of muscle mass.
When there is an increase in the production of oxidants, or the body has insufficient antioxidants, a condition known as oxidative stress can occur. The excess amounts of oxidants damage DNA and other cell components, which may increase inflammation. This is oxidative damage. It suggests that adding antioxidants to your dog’s diet may help protect them against cell damage, which can then potentially contribute to good health and slow the ageing process.
Antioxidants for your dog
The most commonly used antioxidants in dogs are vitamin E, vitamin C and lipolic acid. Vitamin E is important in protecting cell membranes from oxidative damage. To increase a dog’s vitamin E intake, feed your dog meats, poultry and eggs, as well as cereals, fruit and vegetables.
Vitamin C is not just an antioxidant on its own, but is involved in converting oxidised vitamin E back to an active form. For this reason, vitamin C is usually given with vitamin E. Dogs usually produce adequate amounts of vitamin C in their bodies, but in times of physical or emotional stress (e.g. physical injury, moving house, etc.) they may be deficient. If extra vitamin C is needed, then more fresh fruit and vegetables can be added to their diet.
Lipoic acid plays an important role in energy production in cells and is found in liver, kidney, spinach and broccoli.
If your dog is a fussy eater or doesn’t eat much, consider feeding them a prescription pet food that contains extra antioxidants or feed them an antioxidant supplement to support their body as they age.
The beneficial effects of antioxidants on your dog’s body and mind
Antioxidants have been shown to have a number of positive effects on the health of elderly dogs. With age, for instance, dogs can suffer from deterioration in the function of their retina and lens, which can adversely affect their vision. Antioxidant supplementation may protect the structures of the eye from this deterioration.
What’s more, feeding a diet containing antioxidants, as well as fish oil and good quality protein, has been shown to have a beneficial effect on kidney function in senior dogs with early kidney disease.
Vitamin E is one of the best known antioxidants and has shown good results in the management of canine osteoarthritis. Nitric oxide, for example, is an oxide which is involved in inflammation and increased blood supply to the joints, as well as the loss of cartilage on the joint surfaces. The use of vitamin E may significantly reduce the amount of nitric oxide in a joint, which may subsequently have a positive effect on the symptoms of osteoarthritis.
Your elderly dog’s brain can also benefit from a reduction in oxidants. Feeding them a diet rich in antioxidants may actually improve their ability to learn new tasks, for example, and there have been some suggestions that antioxidants may also slow the progress of age-related mental decline.
Antioxidants and cancer
It has been suggested that the use of antioxidants may have some impact on the treatment and prevention of cancer, however it’s important to stress that the evidence isn’t that clear. Some forms of vitamin E appear to protect against cancer, while others have no preventative effect at all.
Oxidative stress can occur in dogs with lymphoma and mammary cancers, and oxidants may actually contribute to the progression of the disease, as well. It’s also possible that increased antioxidants could slow the growth and spread of tumours, and that antioxidants may help to protect the body from the adverse effects of radiation therapy and chemotherapy. On the other hand, these commonly used cancer therapies rely on the production of oxidants to kill cancer cells so the addition of antioxidants to a dog’s cancer treatment protocol could reduce their effectiveness. The result is that the use of antioxidants is a controversial subject amongst both veterinary and human oncologists.
Other supplements that may help senior dogs
Antioxidants are not the only supplements that can make a difference to the well-being of elderly canines, though. Feeding medium-chain triglycerides can have a positive effect on brain function in old dogs. This type of triglyceride can be found in coconut oil. Some dogs don’t like the taste of these triglycerides and adverse effects can include flatulence and loose stools.
The addition of fish oil, which contains omega-3 fatty acids, can improve weight-bearing in the joints of those dogs that suffer from osteoarthritis.
The most important part of meeting your pet’s nutritional requirements is to feed them a good quality, balanced food. Before you add antioxidants or other products to their diet in the hope of improving their well-being, do talk to your vet.
1 Sechi, S., Chiavolelli, F., Spissu, N., Di Cerbo, A., Canello, S., Guidetti, G., Fiore, F. and Cocco, R. (2015). An Antioxidant Dietary Supplement Improves Brain-Derived Neurotrophic Factor Levels in Serum of Aged Dogs: Preliminary Results. Journal of Veterinary Medicine, 2015, pp.1-9.
2 Li, Y., Huang, T., Carlson, E., Melov, S., Ursell, P., Olson, J., Noble, L., Yoshimura, M., Berger, C., Chan, P., Wallace, D. and Epstein, C. (1995). Dilated cardiomyopathy and neonatal lethality in mutant mice lacking manganese superoxide dismutase. Nature Genetics, 11(4), pp.376-381.
3 Muller, F., Song, W., Liu, Y., Chaudhuri, A., Pieke-Dahl, S., Strong, R., Huang, T., Epstein, C., Roberts, L., Csete, M., Faulkner, J. and Van Remmen, H. (2006). Absence of CuZn superoxide dismutase leads to elevated oxidative stress and acceleration of age-dependent skeletal muscle atrophy. Free Radical Biology and Medicine, 40(11), pp.1993-2004.
4 Wang, W., Hernandez, J., Moore, C., Jackson, J. and Narfström, K. (2016). Antioxidant supplementation increases retinal responses and decreases refractive error changes in dogs. Journal of Nutritional Science, 5.
5Hall, J., MacLeay, J., Yerramilli, M., Obare, E., Yerramilli, M., Schiefelbein, H., Paetau-Robinson, I. and Jewell, D. (2016). Positive Impact of Nutritional Interventions on Serum Symmetric Dimethylarginine and Creatinine Concentrations in Client-Owned Geriatric Dogs. PLOS ONE, 11(4), p.e0153653.
6 Rhouma, M., de Oliveira El Warrak, A., Troncy, E., Beaudry, F. and Chorfi, Y. (2013). Anti-inflammatory response of dietary vitamin E and its effects on pain and joint structures during early stages of surgically induced osteoarthritis in dogs. Can J Vet Res., 77(3), pp.191-198.
7 COTMAN, C., HEAD, E., MUGGENBURG, B., ZICKER, S. and MILGRAM, N. (2002). Brain ageing in the canine: a diet enriched in antioxidants reduces cognitive dysfunction. Neurobiology of Aging, 23(5), pp.809-818.
8 Sechi, S., Chiavolelli, F., Spissu, N., Di Cerbo, A., Canello, S., Guidetti, G., Fiore, F. and Cocco, R. (2015). An Antioxidant Dietary Supplement Improves Brain-Derived Neurotrophic Factor Levels in Serum of Aged Dogs: Preliminary Results. Journal of Veterinary Medicine, 2015, pp.1-9.
9 Yang, C., Suh, N. and Kong, A. (2012). Does Vitamin E Prevent or Promote Cancer?. Cancer Prevention Research, 5(5), pp.701-705.
10 Freeman, L. (2009). Antioxidants in Cancer Treatment: Helpful or Harmful? Compendium: Continuing Education for Veterinarians, 31(4).
11 Manteca, X. (2011). Nutrition and Behavior in Senior Dogs. Topics in Companion Animal Medicine, 26(1), pp.33-36.