Beet pulp is a good source of both soluble and insoluble fibre. The soluble fibre helps to nourish the friendly bowel flora. It also slows down the rate at which food travels through the gut; ensuring that there is sufficient time for the extraction of nutrients. This helps to achieve optimal digestion and assimilation. The insoluble fibre increases peristalsis (contractions of the intestinal muscles). It may improve dietary satisfaction, and also contributes to the crunchy texture of the kibble. A good quality fibre source at the correct proportion can be beneficial in helping maintain stable blood sugar, good serotonin levels and controlled release of energy throughout the day. Together, these plus points all work towards a healthy metabolism. Beet pulp has had unwarranted bad press due to claims it is a cheap filler, may turn coats red and is a common dietary allergen. In fact there is no evidence to suggest it can alter coat colour. It contains only a small protein fraction and is therefore an unlikely allergen.
Chicken may be found in dog food in a variety of forms. “Chicken meal” is a dehydrated ingredient used in dry dog food that includes the bone (a good natural source of calcium). “Hydrolysed chicken” is specially processed to render the protein into tiny fractions of such a low molecular weight that they are too small to annoy the immune system, meaning they are non-allergenic. “Fresh chicken” is as the name implies, and it’s added to the food without any prior processing. Chicken has a high biological value (it’s easily broken down into its constituent amino acids), making it an excellent protein source for cats and dogs. It is also a very good source of tryptophan, calcium, potassium and vitamin B6. Many discerning dog owners prefer to see chicken listed as opposed to a generic poultry blend which may include a variety of different species.
Fat is the most efficient energy source for dogs, and 1g of fat contains more than double the calories of 1g of pure protein or carbohydrate. Chicken fat is considered one of the most digestible sources for dogs, and is therefore commonly used. It has a high and consistent level of essential fatty acids, is a source of choline (which is important for the liver and the brain) and is very low in sodium. Dogs with true allergies to chicken may not need to avoid chicken oil if it has been filtered to remove protein molecules.
Egg is a versatile ingredient. The yolk is a good fat source, whilst egg whites contain the purest form of protein found in whole foods. Eggs are also a valuable source of vitamins (all of the B vitamins, vitamin A, vitamin D and Vitamin E) and minerals (including iodine, selenium and phosphorous). Using egg in combination with meat or fish in commercial complete dog food ensures an excellent amino acid profile (providing all of the building blocks of protein that the body needs for a variety of structural and functional purposes). Using whole egg is better than using just the white or just the yolk because the whites contain avidin which binds biotin (one of the B vitamins). The yolk however contains a high concentration of biotin that negates this problem. (Cooking reduces the binding effect of avidin, and this is another reason why whole egg in extruded pet foods is a very safe ingredient).
Like chicken, lamb can also be found in dog food in a variety of forms; usually as “lamb meal” (which is sometimes also described as “dehydrated lamb” or “dried lamb”) or in its fresh state. Lamb is both highly digestible and palatable. It is an excellent source of protein for dogs, and a good source of the amino acid carnitine, zinc, iron and the B vitamins. It was traditionally considered a good alternative protein source for dogs with chicken allergies, but because it is now a very common pet food ingredient, feeds which include it may not be suitable as an exclusion diet unless the lamb (and the ingredient/s used as the carbohydrate source) are novel to the individual dog concerned.
Maize is a member of the starch family of carbohydrates, and is used as an energy source. It also supplies potassium, magnesium and vitamin B6. It is often considered an indigestible ingredient, but when it is cooked within an extruded pet food it is very highly digestible. It’s been described as a common dietary allergen, but the zein protein in corn is actually less allergenic than the glutenin and gliadin that together form wheat gluten. More cases of problems associated with this ingredient are due to its popularity and the fact that many dogs have eaten it, rather than it being particularly provocative in allergy terms. Human (and dog) coeliacs can often safely eat maize, but need to avoid oats and barley (in addition to wheat) due to the similarity of the storage proteins to glutenin and gliadin.
Oats are used as an energy source although they also supply protein. They are low in fat, high in soluble fibre, and a natural source of iron, manganese, zinc and the B vitamins
Potato can provide an alternative carbohydrate source for dogs with grain allergies (although due to its increasing popularity, some dogs may require a more exotic/novel source of carbs if potato was already a staple of their diet at the allergy was diagnosed). It is an excellent source of the vitamins C & B6 as well as potassium, which is good for immunity and energy production. Potato is a safe ingredient, and is not proven to cause or exacerbate arthritic conditions or systemic yeast infections.
The yeast query arose from human nutrition as people with Candida may be advised to eliminate potatoes from their diet. This is because they grow underground and the skin can hold candida cells with the potential to put more yeast into the system. However, potato within extruded pet food is cooked at such a high temperature that these cells would not survive. Another caution (again pertaining to human nutrition) more so than to dogs and cats, is that potato starch is quite quickly converted into sugar and thus could be used as a food source for existing yeast colonies. However at a reasonable proportion, it is unlikely that it would exacerbate a yeast infection.
The arthritis query has again stemmed from human research. However the studies were concerning rheumatoid arthritis. There remains to this date no scientific evidence to support that potato is problematic in dogs with osteoarthritis or related conditions. The respected Arthritis Research UK charity has dismissed claims that people should avoid potato to prevent or alleviate the symptoms of osteoarthritis. In the olden days, people used to dry raw potato juice as a “cure” for arthritis (which is poisonous) and probably made themselves very ill because of it, so this may have had some bearing on things as well.
Rice is a popular pet food ingredient and is used as an energy source. Brown and white rice are both commonly used. Brown rice is traditional perceived as healthier since only the outer hull is removed during processing. Milling and polishing of white rice does destroy some of the B vitamin content as well as manganese, phosphorous and iron. However commercial dog foods are enriched with vitamins and minerals. The reason why some companies use white rice rather than brown is due to the fibre content of brown rice; and if they are using an alternative fibre source such as beet pulp, it’s not necessary to include the additional fibre from the rice.
Fish body oil such as that derived from salmon provides an excellent supply of the long chain omega-3 fatty acids DHA and EPA which are vital components of every cell membrane. They are able to support cell growth, survival and renewal in many organs; and are beneficial to the nervous system, heart, liver, kidneys, joints, brain, eyes, skin and coat. The reason they can help in so many ways is because of their anti-inflammatory properties. Good quality fish oils are micro-filtered to ensure that any dioxins and PCB levels are well below the EC maximum limits.