As with many things, there is no one-size-fits-all answer to this question. Your pet is an individual. When making a decision about what type of diet to feed, you need to consider, among other things, your pet's age, size, breed, and any existing medical problems. And of course, you also must consider the nutrient content of the diet offered.
Quality of the Diet
As with most things, quality matters. However, in the current pet food market, it can be difficult to discern the quality of the diet relative to a company’s marketing scheme. It is recommended to offer your pet a diet that meets the Association of American Feed Control Officials (AAFCO) and World Small Animal Veterinary Association (WSAVA) guidelines. When in doubt, discuss specific diet options with your veterinarian for more individualized recommendations.
What Are Semi-Moist Foods?
Semi-moist food contains a higher water content than dry food, but lower than canned foods. It tends to be fairly high in both salt and sugar. Cats and dogs do not need this much salt and sugar in their diets. In addition, sticky, sugary foods can contribute to dental disease. While dental caries (cavities) in people are related to the amount of sugar in the diet, dental caries are infrequent in dogs and unusual in cats. Tooth loss in both cats and dogs is much more commonly associated with gingivitis and periodontal disease, where inflammation and infection of the gum tissue causes loosening and retraction of the gum tissue around the tooth, which eventually leads to tooth loss. Sticky, sugary foods can contribute to the development of gingivitis and periodontal disease. In general, most experts recommend avoiding semi-moist foods and sticking with a dry or canned option.
Dry Food Myths and Facts
For medium and large breed dogs, most people choose a dry food for several reasons. Larger breed dogs require a larger amount of food than smaller dogs or cats, and dry food is easy to transport, store and prepare. Since canned food contains a much larger percentage of water (usually 80-85%) than dry foods (usually 10% or less), dry food is usually more economical to feed on a per-serving basis, especially when feeding a high quality food. Due to both cost considerations and the ease of use, most pet owners choose a dry kibble for their pet.
Many people also choose to feed their pets dry food in the belief that dry kibble slows the accumulation of plaque and tartar on the teeth by scraping or wiping the teeth while chewing, thereby slowing the progression of dental disease. While dry food exercises the mouth during chewing, the average dry kibble actually does not provide very much mechanical scraping action. When the tip of a tooth comes into contact with regular dry kibble, the kibble shatters before the tooth can penetrate far enough into it for any scraping to take place. However, there are specially designed dental diets on the market, with a kibble designed to hold together longer, allowing more tooth contact before the kibble breaks apart. This allows for more of a wiping effect on the tooth, but even these diets are not a replacement for good dental care. The Veterinary Oral Health Council has a comprehensive list of veterinary dentist-approved products and diets for both dogs and cats. While canned foods may promote a somewhat faster accumulation of plaque and tartar, plaque and tartar will still eventually accumulate no matter what type of food is fed. Regular home care, yearly dental exams and professional cleanings are still essential for optimum dental health.
The Case for Canned Foods
Smaller breeds of dogs and cats obviously eat less than larger dogs, so quality canned foods are often less cost prohibitive. However, smaller breed dogs often have more crowded teeth, providing areas where plaque and tartar easily accumulate. Sometimes owners state that their dog is accustomed to canned food and refuses to eat dry food. These dogs can still be fed canned food, but dental home care needs to be especially emphasized. Pets eating canned food are likely to need annual professional veterinary dental cleanings. In pets with existing dental disease or other causes of oral pain, canned foods can be easier to chew.
Special Considerations for Cats
Until recently, dry food was usually recommended most often for cats as well. However, recent research in feline nutrition is causing some changes in these recommendations. The typical dry cat food is quite high in carbohydrates (often 45% or more) and there is some indication that this may predispose certain cats to becoming overweight or obese, and possibly developing diabetes as they get older. The typical diet of cats in the wild, which usually is mostly mice and other small rodents, is thought to be about 45% protein, 45% fat and only 4-5% carbohydrates. Dry pet food requires a fairly high carbohydrate content in order for the kibble pieces to stick together. However, canned food is typically much lower in carbohydrate content (about 10%). Many veterinary nutritionists are now recommending that cats, especially those with a tendency toward obesity, be fed a canned diet with a protein, fat and carbohydrate content as close as possible to a 'wild' diet. Interestingly, early reports seem to indicate that a canned diet does not seem to increase the incidence of dental disease in these cats.
It is important to note that specific health conditions may affect the type of diet that is recommended for your individual pet. For example, cats with urinary tract problems or animals with kidney disease may benefit from an increased water content in their diet. Oftentimes prescription canned foods are recommended in these situations. Always consult with your veterinarian before making any drastic changes to your pet's diet and have an open dialogue with your veterinarian about specific recommendations for your individual pet.