I had always thought that domestic cats go through a phase in life when they become older and more sedentary, burn up less calories and therefore put on weight unless you fed them less or modify the diet. This is not entirely true.
When domestic cats become older still to an age where they could be described as “geriatric”, they often lose weight and becomes rather frail. We have all seen the geriatric cat with the sad, old eyes and the dull coat looking rather skinny and accepting this is as a normal consequence of advanced years.
This need not be the case according to Dr Mark Peterson DVM writing for the Feline Nutrition Foundation.
He states that the idea that older cats be fed reduced energy senior diets is questionable. Geriatric cats have increased energy requirements and nutritional needs. They have a “higher maintenance energy requirement”. In addition, geriatric cats do not digest protein as efficiently as they did when they were younger. Further, “older cats also require high amounts of protein to maintain protein reserves compared with younger adult cats”.
Therefore unless the geriatric cat has an increased calorific intake through protein he/she is liable to lose muscle mass. Cats get most of their calories through protein and fats not carbohydrates.
This is where it gets complicated and I don’t want to go down a complicated route but simply flag up the concept that geriatric cats require increased daily protein intake compared to young to middle-aged cats.
Young to middle-aged cats require approximately 5.5 g/kg up to 11.5 g/kg. This means, at the lower end, the normal, middle-aged cat requires five and a half grams of protein per every kilogram of body weight daily. As both energy needs and protein requirements increase progressively as the domestic cat ages (starting at 10 to 12 years of age), in order to maintain lean body mass and optimum health, geriatric cats should be on a diet which provides at least 6 to 8 g of high quality protein for every kilogram of bodyweight, daily.
The big question is how do these figures translate to what we give our cat by way of commercial cat food? How do you know that you are giving your geriatric cat 6-8 g of high-quality protein per kilogram of body weight?
It is going to be complicated to work out in my opinion and it may be too complicated for the average cat caretaker or too bothersome. I would suggest that your veterinarian is consulted but the chart below may help.
I hope this helps or at least raises some questions in the minds of cat caretakers. It did for me.