PROOF OF THE PUDDING
Canine nutrition is a can of worms. No one would argue with the fact that feeding the correct food is vital to maintaining health, it’s how to choose such food that is difficult
We need something on nutrition!’ yelled Mr Clark, the Editor. My heart sank and my tummy rumbled ominously. Canine nutrition, quite simply, is a can of worms. Numerous theories are vociferously expounded. Millions are ploughed into marketing. Camps are divided between raw and complete. Owners obsess with protein content when energy is really the key. And so it goes on. And on. But at the end of the day, the proof of the pudding is in the eating…
No one would argue with the fact that feeding the correct food is vital to maintaining health, it’s how to choose it that is difficult. Previous experience of a diet is helpful. Food manufacturers spend much on research and clinical trials but what suits one dog may not suit yours. Many food producers make claims that cannot be substantiated. The lifetime effects of feeding raw have not yet been investigated, making it difficult for your vet to recommend doing so, because there is currently no evidence to back it up. Heh, even understanding what is written on a pet food label is not easy. But it’s a good place to begin.
Water is the most important nutrient of all. Your dog can lose all his fat and half his protein and still survive, but 15 per cent water loss means death. Listed as moisture content in food, water has no energy value, so foods with a high content will usually have a lower energy density. Dry food is about 6 per cent water, while tins typically are around 80 per cent, so a far greater volume of the latter is required to be fed.
One of the energy-producing components of a food, protein content, is confusing and can be misleading. There are 23 amino acids that make up proteins and animals require all of them, although only 10 are essential, because the others can be synthesised in the body. The quality of protein is determined by its “biological value” (BV), which is a measure of how closely it matches a dog’s requirements, along with how well it is absorbed and retained. Egg, which most closely meets these requirements, has been assigned a value of 100 and this allows other proteins to be benchmarked. Thus animal protein, such as chicken, has a BV of about 80, while cereal proteins are around 45. Gelatin, much loved by some pet food manufacturers as it looks lovely, is junk with a BV of 0. You can see, therefore, that it is just not possible to make comparisons between the percentage of protein in different foods without knowing the quality of that protein.
Fat is required for energy, to help absorb fat-soluble vitamins A, D, E and K, to improve palatability and as a source of essential fatty acids. Two of the polyunsaturated fatty acids, Omega 3 and Omega 6 are essential, as they cannot be synthesised. Deficiency of these results in poor reproductive performance, delayed wound healing and a dry scaly skin that is prone to infection. This is most commonly seen in dogs receiving low-fat dry food, especially if it has been stored for too long in warm, humid conditions. Fat is the most expensive component of commercial dog foods.
Carbohydrates are split into two groups, depending on their ability to be digested and absorbed. Digestible carbohydrates, although not essential for dogs (as long as they are receiving adequate protein and fat) are, nevertheless, an economical and easily digested energy source and can also increase palatability. Indigestible carbohydrates are listed as “fibre” and are important for regularising bowel movements and preventing constipation and diarrhoea. Fibre also decreases the energy content of food.
Minerals are collectively listed on pet food labels as “ash”. Not really a great deal of help if you need to know the calcium/phosphorus ration when feeding pups! Suffice to say that calcium deficiency is commonly seen when highphosphorus meats and offal are fed.
One of the benefits of commercial foods is that their vitamin content is known. Homemade foods or raw can be a bit hit or miss. As I said, a can of worms… but food for thought, I hope.