The first thing you can do to keep your pet's skin and coat healthy is to be sure he is healthy and on a good diet. At least one third of my patients get rid of their dandruff, grow more hair, and get an extra shine to their fur by just getting health problems taken care of, and switching to a better diet. Generic diets are sub-standard--they're cheap because they have cheap ingredients. A good diet does not contain artificial flavors, colors, or preservatives. Many pets are sensitive to these factors and may develop dandruff and a dull coat when fed diets containing them. Sulfur dioxide used as a preservative can destroy the B vitamin thiamin.
Hair is 95 per cent protein. This means the second important factor in a good diet is a good source of protein. It should come from meat, not just by-products or gluten meal. A poor protein source can result in sparse hair.
The third important factor in a good diet is a good source of Omega 3 and 6 fatty acids. They are also needed to prevent dandruff and a dry coat. It is difficult to put enough fatty acids into a dry dog food, and canned diets and even homemade diets may not have enough of the omega 3 fatty acids in them. Fat in a dry dog food will become rancid after 6 months on the shelf, and this destroys essential fatty acids. Even though omega 3 oils are not considered essential for dogs, adding them to the diet often brings an extra shine to the coat. Flax oil or fish oil are fine for your dog, but your cat can only assimilate fish oils. Cold water fish such as salmon and tuna are also a good source of omega 3 fatty acids, for both dogs and cats.
Increasing the fats or oils in a diet increases the need for vitamin E. Even more vitamin E is needed if you inadvertently feed food with rancid fat. Fats in dry dog or cat food will start to go rancid 6 months after the product was produced. Canned food lasts for 1 year before you see the same problem. If you are storing up dry food for the year 2000, you may have a problem with rancid fats. Vitamin E can also help with some skin problems involving inflammation or thickening of the skin.
Biotin, riboflavin, niacin and niacinamide are some B vitamins that are important for proper skin health. Pets who are on a vegetarian diet are more likely to have skin problems that respond to B vitamins, but adding B complex to the diet can't hurt. Liver is a source of vitamin A and has a lot of B vitamins, also. A small piece once or twice a week is usually sufficient for skin health.
A variety of minerals is needed for healthy skin. A sluggish thyroid can cause skin problems, and a good source of iodine help it function better. Kelp is a good source of minerals, including iodine.
Some pets just don't absorb nutrients well, even with the best of diets. For them, some digestive enzymes can do the trick, letting them absorb just enough extra that their coat will blossom.
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Rothstein DVM, Emily et al. "Tetracycline and Niacinamide for the Treatment of Sterile Pyogranuloma/Granuloma Syndrome in a Dog," Journal of the American Animal Hospital 33(6):540-543, Nov/Dec 1997.
Steel, R.J. "Thiamine Deficiency in a Cat Associated with the Preservation of 'Pet Meat' with Sulphur Dioxide" Australian Veterinary Journal 75(10):719-21, October 1997.
Vitale, C.B. et al., "Vaccine-Induced Ischemic Dermatopathy in the Dog," Veterinary Dermatology 10(2):131-142, June 1999.