By Fiona Robertson, Cert A.C.N
Photo Credit to Carolyn West
Our dogs give us their all, and they deserve special attention when they retire from work. Proper nutrition is an important contributor to healthy aging in dogs and is often overlooked. While there currently isn’t any difference in the established nutrient requirements for senior dogs vs. adult dogs, current literature shows that specialized nutrition can help with some of the “older dog” issues commonly experienced by our senior canines. These include weight gain, osteoarthritis, cognitive decline, gastrointestinal disorders, and diseases such as chronic kidney disease and cardiovascular disease.
Part 1 of this article talks about Weight Gain and Arthritis.
Weight Gain.
The very first thing we need to consider is energy intake. Many senior dogs are less active and therefore are not burning as much energy as they were as younger adults. A reduction in energy intake (in the form of kcals or “calories”) is usually warranted to prevent weight gain. This means our retired partners should probably not continue eating the same diet as they did as younger adults. It is important to find a food that matches their energy needs – underfeeding a high calorie food may expose your dog to nutrient deficits, which can lead to the development or exacerbation of disease (please review the previous OBCC blog post written on this subject “Feeding instructions on Dog Food Packaging”).
Keep in mind that some diseases can cause weight loss, either indirectly through inappetence or directly due to metabolic changes and cachexia. Cachexia is the catabolism of lean muscle mass to provide amino acids for energy in the chronically ill. It can be caused by inadequate energy (calorie) intake, excessive nutrient losses and/or altered metabolism. It is most often observed in the late stages of kidney disease, heart disease, cancer and other immunodeficiency diseases. Many diseases can be managed with the help of a therapeutic or prescription diet. Early intervention is the key to extend the quality of life for affected senior dogs.
Osteoarthritis.
Preventing weight gain through calorie reduction is the first step to maintaining joint health in our senior dogs. We know that excess weight puts more strain on joints, which can contribute to arthritis pain. Additionally, obesity itself is an inflammatory disease and may directly exacerbate joint damage (1).
It is also well understood that Omega 3 fatty acids are important in alleviating arthritis symptoms. EPA (Eicosapentaenoic Acid) is a fatty acid found most commonly in fish body oil which produces immunoregulatory molecules called eicosanoids that have local hormonal and inflammation-mediating functions. The eicosanoids synthesized from EPA provide anti-inflammatory benefits in canine osteoarthritis. Choosing and dosing a good omega 3 supplement is not so easy! Many have shown (in third party tests) to be oxidized (“rancid”)(2). Therapeutic dosing should be under the guidance of a professional, as high doses may be contraindicated in certain conditions. And because fish oil is 99-100% fat, it is very high in calories (~9 kcal per gram). Our “Easy Keeper” seniors may not have any calories left for a lot of fish oil without changing their base diet to a lower calorie ration.
Reactive Oxygen Species (ROS), or “free radicals”, which are a by-product of fuel oxidation that can damage cells, are considered main contributors in the development of osteoarthritis (3). Oxidation cannot be avoided – it is the by-product of fuel (energy) burning (the metabolism of fat, carbohydrates and protein). Antioxidants scavenge undesirableROS and thus are important in reducing oxidative stress and subsequent joint damage. Normal dogs can maintain adequate antioxidant systems in the body but these systems can be overwhelmed in some dogs including hard working dogs and seniors, especially in the presence of chronic inflammation, as seen in many disease states including canine osteoarthritis.
Commercial dog foods balanced to nutrient requirements should be providing (at least) the minimum requirement of each of the main antioxidants vitamin E and Selenium required for normal (healthy) dogs. Many rations also contain non-essential (but beneficial) antioxidants such as vitamin C and CoQ10 (for example). We can probably assume that some of the antioxidants are lost “preserving” the food, so will be unavailable to the dog. Most pet foods will have factored preservation into their formulations, but additional, conservative supplementation of antioxidants may be beneficial in many dogs, including seniors with joint pain. Higher amounts may be warranted in the presence of high dietary Omega-3 fatty acids, which are prone to oxidation, but be careful if supplementing, as very high doses of single antioxidants can have an opposite effect; becoming pro-oxidants and increasing cellular damage. Additionally, selenium has a known safe upper limit for dogs, and overall dietary intake of this nutrient should not exceed this limit. Vitamin C can also cause gastrointestinal and urinary problems if over supplemented. Vitamin E has blood thinning effects in very high doses.
Other supplements for joint health may or may not be beneficial. Although many people report alleviation of symptoms when their dogs are taking one or both, glucosamine and chondroitin don’t appear to have any anti-inflammatory effects(4). Overall, research is inconclusive on the potential effects of supplements such as collagen, CBD oil and other nutraceuticals, but initial findings suggest promise. Always work with your dog’s professional care team when adding any supplements to your dog’s diet and try to buy ones that have been third party tested. And remember that the base diet should be providing all essential nutrients before adding supplements.
References:
(1) Theyse, L. F. H., & Mazur, E. M. (2024). Osteoarthritis, adipokines and the translational research potential in small animal patients. Frontiers in Veterinary Science, 11, 1193702. https://doi.org/10.3389/fvets.2024.1193702
(2) Best fish oil and omega-3 supplements? ConsumerLab tests reveal some are rancid. (2023, October 24). ConsumerLabs. Retrieved February 27, 2026, from https://www.consumerlab.com/news/best-fish-oil-supplements/10-24-2023/
(3) Blanca, P., Luisa, F. M., Guadalupe, M., & Fátima, C. (2024). Oxidative Stress in Canine Diseases: A Comprehensive review. Antioxidants, 13(11), 1396. https://doi.org/10.3390/antiox13111396
(4) Barbeau-Grégoire, M., Otis, C., Cournoyer, A., Moreau, M., Lussier, B., & Troncy, E. (2022). A 2022 Systematic Review and Meta-Analysis of Enriched Therapeutic Diets and Nutraceuticals in Canine and feline Osteoarthritis. International Journal of Molecular Sciences, 23(18), 10384. https://doi.org/10.3390/ijms231810384