Table 3 . Dietary factors requiring consideration in healthy senior cats and all breeds of senior dogs . ( This table spreads across pages 29 and 30 .)
Dietary factor Cats Dogs Protein
Fat
Unnecessary protein restriction in senior cats and dogs is potentially more detrimental than a deficiency in younger animals ( Churchill , 2018 ) and may exacerbate loss of lean tissue and protein-calorie malnutrition ( Hutchinson et al ., 2011 ). Optimal intake can help to prevent sarcopenia ( Corbee , 2018 ). Quality of protein source is also a key consideration and should be of high biological value ( BV ), providing efficient utilisation and reduced bacterial metabolites ( Fascetti , 2010 ; Hutchinson & Freeman , 2011 ).
Approximately 1 in 5 cats over the age of 14 years have a reduced ability to digest protein , which can contribute to weight loss ( Perez-Camargo , 2004 ). This has implications for the amount , quality and digestibility of dietary protein given to senior cats .
Protein requirements increase in senior dogs due to increased protein turnover and reduced protein synthesis . Diets with a higher protein : calorie ratio , with 25 % of calorific intake from quality protein , can help to minimise loss of LBM ( Churchill , 2018 ).
In comparison to carbohydrate and protein , fat has a higher energy density . An increased dietary source may be advocated in situations requiring maximisation of energy intake in senior cats and dogs .
Fat digestibility is impaired in approximately one third of senior cats ( Perez-Camargo , 2004 ), with a subsequent impact on the digestibility of vitamins B and E , potassium and other minerals ( Laflamme , 2012 ).
An energy-dense diet may be especially useful for senior dogs in situations where food consumption is either insufficient to maintain an optimal weight or reduced for reasons such as cognitive dysfunction .
Micronutrients
Fatty acids
Medium-chain triglycerides ( MCTs )
Antioxidants
Vitamin and mineral requirements of ageing dogs and cats are similar to adult maintenance requirements . Restriction without medical justification has no proven benefit but appropriate nutrient modulation may be required in the presence of specific diseases and when poor digestibility , lower absorption and / or increased losses are expected ( FEDIAF , 2017 ; Villaverde , 2017 ).
Omega-3 ( also known as n-3 ) and omega-6 ( also known as n-6 ) fatty acids are associated with a number of health benefits and improved longevity in cats ( Cupp et al ., 2007 ). Omega-3 long-chain fatty acids ( LC-PUFA ), including eicosapentaenoic acid ( EPA ) and docosahexaenoic acid ( DHA ), are particularly valuable in modulating inflammation . Optimal intake may therefore benefit senior animals with inflammatory conditions , including osteoarthritis , and those with diseases that predispose them to cachexia . Omega-3 fatty acids have a role in reducing inflammatory mediators that may be present in sarcopenic dogs and cats .
Unlike in dogs , MCTs have no demonstrable effects in improving cognitive function in elderly cats .
Ageing is associated with a reduction in the ability to metabolise and utilise glucose as the primary energy source for neurons , affecting memory , learning and awareness . The provision of MCTs as an alternate cerebral energy source can help to offset cognitive decline and preserve brain structure , thus maximising brain function in senior dogs ( Pan et al ., 2010 ).
Antioxidants play a role in preventing cell damage caused by oxidative metabolites and in supporting the immune system .
Highly digestible diets rich in antioxidants and omega-3 fatty acids , as well as interactive toys and puzzles and environmental enrichment , may all help to slow the development of sarcopenia in cats ( Ray et al ., 2021 ).
Oxidative damage plays a significant pathophysiological role in ageing and the pathogenesis of age-related diseases such as canine cognitive dysfunction .
30 Veterinary Nursing Journal