Senior diet and foods for older cats are so well-established that nearly everyone uses them. But do they help?
Here are some of the claims:
- Reduced strain on the kidneys
- Maintenance of optimum body weight and muscle mass
- Additional nutrients important for ageing
Are they correct? Could these diets be harmful instead? Let’s look at the evidence.
Senior vs Adult Cat Foods
31 foods marketed for senior cats (19 dry & 12 canned) were compared with 59 foods marketed for adult cats. Here’s what they found:
- Senior cat foods had significantly higher crude fibre
- No significant differences were found in protein, fat, calorie, or mineral levels
The authors concluded that foods for senior cats in general have a nutrient content and caloric density similar to foods for adult cats.
This does not mean that senior diets are bad, or useless. What’s going on here is best explained by looking at the nutritional needs of older cats.
What Senior Cats Should Eat
As of 2020, there is no evidence that senior cats need different food to adult cats. There are also no AAFCO guidelines for what a senior diet should or shouldn’t contain, leaving pet food companies completely in the dark.
Therefore, while the companies are almost certainly trying their best, without established standards they can only use their own judgement. This is why many senior diets seem half-hearted and make fairly wishy washy statements instead of real promises.
Most claims revolve around kidney disease and weight management. These are tricky areas worth exploring a bit deeper.
Senior Cat Weight Management
Cats from middle age become less active and often need less calories. Therefore, in general, it’s often good that a diet for cats between 5 and 11 has less energy per gram. However, as cats age further, the prevalence of obesity declines, and some healthy cats may even become underweight. Therefore, a diet for some cats over 11 may need to contain extra calories.
The problem is the one-size-fits-all approach. There is no way to predict the nutritional needs of an individual cat as they age. In fact, I consider it mildly dangerous to restrict senior cats without veterinary advice.
Kidney Disease Prevention
Senior diets claim to help the kidneys. This is based on the knowledge that cats in early kidney failure benefit from restriction in dietary protein and especially phosphorus.
In contrast, there is no evidence that restriction of normal cats is beneficial. Furthermore, most senior diets currently available aren’t restricted enough to make a difference even if the benefit exists. However, there is a way that senior diets might help.
A feeding trial over 18 months compared cats on a more heavily restricted senior diet (Royal Canin Senior Consult Stage 1) with cats fed normal food.
They found that although no fewer cases of kidney disease were observed, parathyroid hormone levels stayed lower in the treated cats. This hormone is known to be elevated in cases of kidney disease. Therefore, there was certainly no harm done, and possibly a small unproven benefit.
Senior diets that make real, informed restrictions may especially be helpful for the time between when a cat’s kidneys start to fail and when it’s detected by your vet (at which time special kidney diets proven to help will be used). In this phase, being on any restriction is better than nothing. But this won’t be necessary if your cat goes to the vet often, and you get blood testing done regularly.
So here are my recommendations…
The Best Food For Senior Cats
A diet should be chosen individually for each older cat based on three factors:
- Other health issues
If a senior cat is healthy, as judged by a veterinary exam and blood tests, then an adequately restricted senior diet may be helpful. However, for nearly all cats, there’s a better diet based on their personal needs. Examples include:
- Dental diets to maintain oral health in senior years
- Iodine restricted diets for thyroid disease
- Weight management diets
- Diets for food intolerances and allergies
- Higher palatability or digestibility foods for weight loss
And the list could go on. Well-made senior diets may have a role in cats with kidney disease who refuse to eat the prescription diets, but these are rare. For everyone else, there’s usually a more tailored approach.
Senior care is much more about being tuned in and responsive to your cat’s needs than about any single food. The main thing is to keep going to your vet, and in fact to go more often. Then all you have to do is adjust the diet based on whichever is the most important concern. The answer is almost never a generic one.
By Andrew Spanner BVSc(Hons) MVetStud, a vet in Adelaide, Australia. These blogs are from a series regularly posted on email and Twitter. Subscribe via email here to never miss a story!
Have something to add? Comments are welcome below and will appear within 24 hours.
Geddes, R. F., Biourge, V., Chang, Y., Syme, H. M., & Elliott, J. (2016). The effect of moderate dietary protein and phosphate restriction on calcium‐phosphate homeostasis in healthy older cats. Journal of veterinary internal medicine, 30(5), 1690-1702 Full Article.
Summers, S. C., Stockman, J., Larsen, J. A., Sanchez Rodriguez, A., & Zhang, L. (2020). Evaluation of nutrient content and caloric density in commercially available foods formulated for senior cats. Journal of Veterinary Internal Medicine, 34(5), 2029-2035 Full Article.