Vet Q & A
Question: I buy my dog's food at the supermarket, but his coat isn't shiny and I've heard that other dog food's sold at the feed store and vet's office carry may be better. How are these dog foods different from the one's I buy?

Answer: That's a good question, one I'm often asked. What you need to do is read the ingredient labels on the dog foods, whether dry or canned, to try and figure out which has the items that would suit your dog best. First look at the meat. It should be listed first and will say exactly what the protein source is. The top of the line foods will list the meat source by itself, such as chicken or beef. If the word meal is included behind it, such as chicken meal, then it means that things other than muscle meat have been added, usually things like sinew, tendons, and cartilage. These are cheaper additives and increase the protein level in the dog food; however this type of protein is more difficult for a dog to digest, and some meat meals may not contain all the amino acids (amino acids are what make up protein) needed by dogs. It's hard to tell the quality of the meat included in the meal, however price may be the easiest factor to look at since less expensive foods generally contain less muscle meat. Many less expensive dog foods contain soy as a source of protein and it will be listed on the label if it is in the product. Soy is a poor source of protein for dogs as most cannot digest the plant fiber that soy is made of. Soy requires the digestive enzyme cellulase to break it down so digestion can occur. Dogs do not have or make cellulase, this digestive enzyme is only found in the fresh plant, and so the protein in soy is not digested or used. Some dogs also can have an allergic reaction to soy, often Labrador Retrievers. The carbohydrate source should also be checked. This is usually a grain product; the most common ones are corn, rice and wheat. Some dogs can be sensitive to different grains according to how well they digest them. Easiest to digest is usually rice. Corn is high in natural sugars and should be avoided by diabetics and overweight dogs. Fruits and vegetables are also used by some dog food companies in addition to or instead of grains as a carbohydrate source. Most dogs do very well on theses products however some may not digest the fruit easily and produce gas. Adding a digestive enzyme can help this problem if a food of this type seems best for your dog. Preservatives are another ingredient that can be checked. Many less expensive foods in the market use ethoxyquin as a preservative, a toxic additive that can be a carcinogen. Ethoxyquin was banned from use in people food in 1957, and the allowed level in pet food was recently reduced. Try to avoid dog foods with this ingredient in it. Acceptable preservatives are Vitamin E (also listed as tocopherols) and Vitamin C (also listed as ascorbic acid). Avoid dog foods that have been dyed many colors, as food dyes, especially red, are responsible for many health problems in dogs. Foods that contain semisoft pieces are made of a substance called propylene glycol, which should be avoided due to associated liver problems when consumed on a regular basis. There are other factors but this will give you a start so you can evaluate different dog foods.

Question: My 14 year old cat is looking very thin. He's always hungry and seems restless sometimes. What could be the matter with him?

Answer: There are a variety of causes for thinness in older cats, however in your cats' case the weight loss combined with constant hunger and restlessness usually describes hyperthyroidism or excessive output of hormones by the thyroid gland. This has been an increasing problem in cats over the last 20 years. The most common cause is a non-cancerous tumor (usually a type called a functional thyroid adenoma) that can affect one or both sides of the thyroid gland. Other symptoms that can occur are increased urination, increased drinking, vomiting and diarrhea. Hyperthyroidism can be confirmed by a simple blood test of T4, one of the hormones the thyroid secretes. The cause of this condition has been linked to a toxic substance that is in the material used to line the inside of the pop-top type cat food cans. Treatment options to control hyperthyroidism are radioiodine therapy, thyroidectomy, or administration of an antithyroid drug. The choice of treatment will depend on how advanced the hyperthyroidism is and if the health of the liver and kidneys has been affected. When trying to decide on treatment options it's best to have a complete blood chemistry profile checked on the affected cat to make sure the liver and kidney enzymes are normal. Radioiodine therapy, where radioactive iodine is administered, taken up by the thyroid gland and destroys the overfunctioning thyroid tissue, is very effective. Price varies, but it can be expensive, and usually the cat must be referred to a specialty veterinary clinic for administration. Thyroidectomy, the removal of the affected gland or glands if both sides are affected, works well as a treatment, but can be a tricky surgery since the parathyroid lays next to the thyroid, is very tiny, and must not be removed. The surgery is very specialized and is most often performed by a board certified surgeon. Using the antithyroid drug methimazole, which blocks thyroid hormone synthesis, as a treatment is effective but cats on the medication should have their CBC profile checked a few times during the first three months of use to make sure their red blood cells have not been adversely affected. If liver and kidney enzymes have become elevated before the hyperthyroidism has been diagnosed, acupuncture and homeopathics can be used to help lower the levels.