Older cats need food they can digest easily.

A low residue cat food contains ingredients that are very easy to digest.
So what should you feed your favorite feline? The answer is simple ~ wet food. Dry kibble may be cheaper and easier, but most commercial brands lack what your cat needs, mainly because: A) they are water-depleted, which inhibits urinary tract health, increasing your cat’s risk for urethral obstructions; B) they are high in carbohydrates, which negatively impact your cat’s blood sugar levels and can result in a serious hypoglycemic state; C) the bulk of protein included is from plants, whereas your cat needs animal protein; and D) they are highly processed, resulting in the destruction of nutrients. On the other hand, most wet foods provide a high water content, low carbohydrates, animal-based protein and are more easily digested and utilized by your cat’s body. Besides these health benefits, the variety wet foods provide keep your cat from getting bored by eating the same dry kibble meal after meal.
In addition to easier digestion, when you transition your cat to raw food, you can expect to see the following
According to recent studies in various species, antioxidants in foods such as corn may potentially reduce the risk of some forms of cancer, heart disease, arthritis, strokes, atherosclerosis, cataracts, and slow the aging process.2 Betacarotene, vitamin E and lutein are antioxidants in corn that help protect key cell components from damage.3 Also, cooked ground corn is highly digestible so pets can easily absorb corn's important nutrients.4,5,6 In addition to easier digestion, when you transition your cat to raw food, you can expect to see the following noticeable benefits:*Raw is considered most easily digested, nutrient available form of cat food.Cat food contains fruits and vegetable ingredients easily digested by cats
While these are excellent sources, it’s important to recognize that all proteins are NOT created equal. Proteins have different levels of amino acids that impact the value of the protein. Animal proteins are best as they are the easiest to digest and they also contain more of the essential (and non-essential) amino acids your cat requires. Plant-based proteins are acceptable, but your cat needs animal proteins, so be sure their food is high in those types of protein.If your cat is doing well on his current diet, then there may be no need to change to a different formula. Some brands make a Senior cat food which is specially formulated to deliver ingredients which are more easily digested than standard adult cat foods. Senior cats are more likely to develop health issues related to intestines and kidney disease. There are diets specifically formulated to benefit cats with these issues which may help slow the progression of these diseases.Feeding more (or only) canned food is another way–one that is often easier for people to deal with. Canned foods are higher in protein, and lower in carbohydrates, than dry foods. Their high water content increases the cat’s overall fluid intake, which keeps the kidneys and bladder healthy. Because the ingredients are more easily digested and utilized by the cat’s body, canned foods produce less solid waste in the litterbox.A low residue cat food contains ingredients that are very easy to digest. Cats digest animal protein the most easily. A small amount of fat is also digestible but some cats have a harder time with fat than others. Low fat animal protein and under 4% of fiber is the best. A food with a high moisture content will also help your cat digest the ingredients. The food should be low in grains and carbohydrates as cats don't digest these easily. When feeding our companion cats, the most logical strategy is to feed the diet that most closely mimics the natural prey diet. A homemade diet is an excellent way to accomplish this. Feeding more (or only) canned food is another way–one that is often easier for people to deal with. Canned foods are higher in fat and protein, and lower in carbohydrates, than dry foods. Their high water content increases the cat’s overall fluid intake, which keeps the kidneys and bladder healthy. The higher fat contributes to skin and coat health. Because the ingredients are more easily digested and utilized by the cat’s body, canned foods produce less solid waste in the litterbox.Canned food: Probably the easiest, healthiest way to feed your cat, and for FIV+ cats, it probably is the best option. We highly recommend looking for brands that are “human quality,” rather than “pet quality,” because of the higher standards. By being canned, the food is still cooked, but not for anywhere near as long as dry food, with the added benefit of being left wet despite the cooking process. With the shorter cooking time and the lack of dehydration, the food is left more bioavailable for the cat, meaning that the nutrients in the food are more easily digested and used.