Senior Cat Food Compared: Senior Is Not a Life Stage

There are two life stages in pet food. Growth and reproduction, and adult maintenance. That is the entire list recognised by the AAFCO nutrient profiles that regulate the label on the bag.

Senior is not one of them. A food marketed for older cats is, legally, an adult maintenance food with a word on the front, and there is no minimum standard a manufacturer must meet to print it. Two bags both saying "Senior 7+" can differ more from each other than either differs from a standard adult food.

This is not a reason to dismiss the category. Several senior formulas are carefully made and genuinely suited to older cats. It is a reason to stop treating the word on the front as the specification and start reading the panel on the back, because the word is doing no work at all.

What actually changes in an ageing cat

Three things change enough to matter for feeding. Notably, none of them is "needs less protein".

Muscle loss. Ageing cats lose lean body mass, and their efficiency at digesting and using protein tends to fall rather than rise. The practical consequence is that many older cats need more protein than they did at five, not less, simply to hold the muscle they have. A cat that looks bony over the spine and shoulders while still weighing the same has lost muscle and gained fat, and cutting protein makes that worse. See crude protein and amino acid profile.

The old advice to restrict protein in healthy seniors was borrowed from kidney disease management and applied far too broadly. It has not held up.

Body condition drifts, in both directions. Middle-aged cats tend to gain. Cats past about eleven tend to lose. Both matter, and the direction tells you different things — which is why a number on a scale is less useful than a body condition score from your vet, ideally recorded at every visit as the WSAVA global nutrition guidelines recommend.

Eating becomes less comfortable and less appealing. Dental disease is extremely common in older cats and genuinely painful — see periodontal disease and feline dental resorption. Smell declines with age too, and cats eat largely by smell. A cat that has gone off its food has often not become fussy; it has developed a reason.

The most important thing on this page

An older cat losing weight without you trying is a veterinary appointment, not a shopping decision.

Unintentional weight loss is one of the most useful early signals in feline medicine, and the usual causes are all diagnosable: hyperthyroidism, chronic kidney disease, diabetes, intestinal disease, dental pain, cancer. Several of these are very manageable when caught early and considerably less so when caught late.

Buying a higher-calorie food to counteract the loss feeds the cat around the problem and buys the disease several months of uninterrupted progress. Bloodwork and a urine sample first. Then feed to whatever you find. The same applies to vomiting, increased thirst, or a change in litter box habits.

Related, and worth stating plainly: do not put a healthy cat on a therapeutic renal diet as a precaution. Those diets restrict protein and phosphorus because that helps cats with diagnosed, staged kidney disease. In a healthy cat you get the restriction and none of the benefit, and the protein restriction runs directly against the muscle maintenance an old cat needs. See prescription diet.

Reading the label properly

Four things on the back of the bag are worth more than everything on the front.

The AAFCO statement. Look for the phrasing. "Formulated to meet the nutritional levels established by the AAFCO cat food nutrient profiles" means it was calculated on paper. "Animal feeding tests using AAFCO procedures substantiate that this product provides complete and balanced nutrition" means it was actually fed to cats. The second is a stronger claim. See AAFCO statement and life stage formula.

Protein, converted properly. The guaranteed analysis is as-fed, so wet and dry foods cannot be compared directly — an 8 percent protein wet food may well be higher in protein than a 30 percent dry once you account for water. Convert to dry matter, or compare like with like. See wet versus dry and moisture.

Calories per can or cup. Densities vary by more than half between products, so "one cup" is not a unit and a food change can quietly become a fifteen percent ration change. See caloric density.

Who made it. Whether the company employs a qualified nutritionist, runs feeding trials and does its own quality control matters more than any ingredient on the list.

The comparison, in practice

Wet food is the default worth defaulting to for older cats. It carries moisture, which suits cats with reduced thirst drive and any degree of kidney compromise; it is easier on a sore mouth; and it is generally more palatable to a cat whose sense of smell has faded.

The large manufacturers with feeding trials and in-house nutritionists are the conservative choice here, and conservative is the right instinct for an old cat.

If your cat is holding weight poorly and the vet has ruled out disease, a higher-protein wet formula is the sensible direction — more protein, not fewer calories.

Dry food is not disqualified. It is convenient, it is cheaper per calorie, and plenty of old cats do well on it — particularly alongside wet food rather than instead of it. If your cat prefers dry and is drinking well, a senior dry formula from a serious manufacturer is a reasonable base.

For the specific and common problem of an old cat that has simply stopped finding food interesting, high-moisture, strongly aromatic products are the practical tool — warmed slightly, offered often, in small amounts.

How this goes wrong

What to skip

• Any food chosen because the bag says senior. It is not a standard. The panel is.
• Protein restriction without a diagnosis. The single most damaging piece of outdated advice in this category.
• Prescription diets bought without the prescription. They exist to treat specific diagnosed disease, and they are the wrong food for a cat that does not have it.
• Dental treats as a substitute for dental treatment. A painful mouth needs examining under anaesthetic, not a crunchy biscuit. See how do I brush my dog's teeth for the equivalent home-care reality.
• Switching foods to solve a symptom. Weight loss, vomiting and appetite change are diagnostic information. Spend them at the vet, not in the aisle.

How to choose

If your cat is a healthy weight, eating well and has normal bloodwork, change nothing. Age alone is not a reason. See when should I switch to senior food.

If you are choosing anyway, choose wet, from a manufacturer that runs feeding trials, with protein on the higher side rather than the lower.

Get bloodwork annually from about seven, and twice yearly past eleven. It is the single highest-value thing on this page, and it is not a food.

And weigh the cat at home every month or two. A steady half-kilogram loss over six months is invisible in the living room and completely obvious on a kitchen scale, and finding it early is worth more than any bag you can buy.