Just as human medical recommendations change based on the most recent scientific findings, so do Veterinary medical recommendations. Within the past few years, veterinary science has discovered a link between several serious disease processes and dry cat food.
Until recently, dry food with considered the 'best' food to feed cats, and was advertised aggressively to consumers and veterinarians. This opinion has changed as it has been found that feeding dry food may actually have a detrimental effect on the health of your cat. An increasing number of American Veterinary Medical Association members, including board certified veterinary internists, are now strongly recommending canned food for cats instead of dry food.
As obligate (strict) carnivores, cats are very different from other species in their nutritional needs. Cats rely mainly on nutrients found in animals- high protein, moderate fat, and minimal carbohydrates to meet their nutritional needs. Animal based proteins also provide complete amino acids such as taurine, arginine, cysteine, and methionine. These are essential for cats whose bodies don't make them in adequate amounts.
Cats in the wild thrive on a high-protein, low carb diet consisting of approximately 1 to 2% carbohydrates as part of their daily diet. Dry cat food diets contain as much as 45 - 50% more carbohydrates. Canned cat food contains a far smaller carbohydrate content, some as low as 3 - 4%.
Compared to dogs and humans, cats require a much higher amount of animal-based protein in their diet. This stems from the cats' inability to break down liver enzymes. If a diet is not high enough in protein, the body will begin to utilize and attack the protein in the cat's own muscle, leading to muscle wasting. Because it is without the fillers of carbohydrates, such as wheat, grain and corn, canned cat food has a higher protein content.
Having evolved on the deserts of Africa, cats adapted to the environment by having their water requirements met mostly by the moisture found in their prey. This natural diet contained at least 65% water. Commercial dry food contains no more than 10% moisture. Having low thirst drives, cats typically don't drink enough water to make up for what they're getting and what they need. By contrast, commercially prepared canned food typically contains 40 - 45% water.
Dry food diets have been shown to contribute to many potentially life-threatening problems in cats. The feline inability to metabolize the high-levels of carbohydrates in dry food wrecks havoc on blood sugar levels and can lead to diabetes. Many insulin-dependent diabetic cats have gone into remission when transitioned to a low-carbohydrate 100% canned food diet.
Kidney disease is probably the leading cause of mortality in the feline. Cats being fed a primarily dry food diet are chronically dehydrated. Chronic dehydration plays a large role in kidney failure.
Bladder and kidney stones are very common in cats and can be life-threatening. When a cat is on a diet of water depleted dry food they produce a highly concentrated urine. This increases the chance of these crystals forming into stones. A canned food diet will keep the proper amount of water flowing through the urinary tract system and help maintain health.
Being unable to metabolize high levels of carbohydrates can lead to feline inflammatory bowel disease IBD which can cause chronic vomiting and diarrhea and or constipation.
Obesity is one of the most common health problems in cats today and is directly related to high carb, calorie dry Foods. Most cats will lose weight rather easily when fed a 100% canned diet.
Long-standing claims that cats have less dental disease when fed dry food versus canned food are grossly overrated, inaccurate, and not supported by recent studies. For optimal oral health, most veterinarians are recommending daily tooth brushing and a once a year professional cleaning.
It can be difficult to transition a dry food addict onto a more healthy and natural canned diet. The single biggest mistake humans make is to say that their cat 'won't touch' the new canned food then panic and fill the bowl with dry food.
Transitioning a cat from a dry food diet to a canned food diet takes time and patience. Cats are typically very resistant to such a drastic change in the texture of their food.
If your cat has been eating a dry food on a free choice basis, take up the food and establish a schedule of two feedings per day. Leave the food dry or canned down for 20 minutes, then remove the uneaten portion. Repeat in 8 to 12 hours. Once the cat is on a schedule he will be more enthusiastic about food during the scheduled meal times and will be more inclined to try something new canned food.
Patience and persistence on the guardian's part are key elements in successfully transitioning a cat to a 100% canned food diet. It can be a very slow process and can often take several months or longer to make the transition, but in terms of overall, long term health it is well worth the effort.
Elizabeth Llewellyn is a feline welfare and behaviour specialist with 30 years experience working with cats in a variety of settings including rescue, breeding, boarding, grooming and veterinary. She lives in Chittenden County Vermont with her three cats.