DEAR DR. FOX: I am writing to you, as I am concerned about how we feed cats.

I have a friend who had to have her female cat put down in December. The cat was 12 years old. My friend fed the cat dry food only. The vet said the cat had kidney failure. She had stopped eating and drinking.

Now my friend has another cat she adopted from the SPCA, Annie. Annie is 6 years old, and she spent two years at the shelter. My friend was told to feed the cat both wet and dry food. She gave Annie both foods for a couple of weeks, but now she gives only the dry food.

Is it true that a cat should have both wet and dry food? Is it safe to feed a cat only dry food? I have a neighbor with a cat, and he told me the cat should have wet and dry food.

I don't want this cat to end up like my friend's last cat. I just want to know what's best for the cat. My friend doesn't believe me when I say she needs to feed both kinds. -- P.E.S., West Long Beach, N.J.

DEAR P.E.S.: I appreciate your letter and you have every reason to be concerned about your friend's cat being fed just dry cat food.

Many cats become addicted to a dry food diet, and it is highly advisable to feed a corn-free, grain-free dry food (you can soak it if the cat does not drink much water). For details, check my website, DrFoxVet.com, and visit feline-nutrition.org for excellent information.

Ideally, cats should be fed a cereal- and soy-free diet -- canned and dry -- or raw-frozen or rehydrated freeze-dried, nutritionally balanced formulations. This will help prevent a host of all-too-common diet-related diseases in middle and old age. Cats fed standard dry food continue to suffer in spite of the medical evidence of the harm of poor-quality protein and high fat content of so many manufactured dry cat foods.

DEAR DR. FOX: I agree with you 100 percent on using gloves while handling birds.

Years ago, I was trying to catch one of my finches with my bare hands. The bird bit my finger, but I didn't give it a second thought. Within 24 hours, a red streak was going up my arm. After going to an urgent care facility, it was determined that the finch bit me on a paper cut on that finger, and it became infected.

To this day, I wear heavy gloves when handling my birds -- they bite really hard and can break the skin. -- L.S., St. Louis

DEAR L.S.: Your letter is a welcome addition to the debate raised by one bird "expert" (J.M. from Naples, Fla.) who castigated me for advising people to wear gloves when handling birds who are not fully socialized or who are fearful or aggressive.

This should be standard practice for those with little expertise in handling birds, reptiles and small mammals. Bites and scratches can result in serious infections, and, as I stress repeatedly, the pain could make the handler drop the animal with potentially fatal consequences.

DOGS AND HUMANS WITH OCD SHARE BRAIN CHARACTERISTICS

Canine compulsive disorder is similar to human obsessive-compulsive disorder in practice and physiology, according to recent research. MRI images of 16 Doberman pinschers showed that those with canine compulsive disorder had structural brain characteristics similar to those of human patients with OCD. Veterinarians from Tufts and Purdue universities collaborated with McLean Hospital in Massachusetts for the study. The findings may help develop treatments for canines and humans with compulsive disorders.

(Send all mail to animaldocfox@gmail.com or to Dr. Michael Fox in care of Universal Uclick, 1130 Walnut St., Kansas City, MO 64106. The volume of mail received prohibits personal replies, but questions and comments of general interest will be discussed in future columns.

Visit Dr. Fox's website at DrFoxVet.com.)

DEAR DR. FOX: I am writing in reference to a recent letter in your column about a beagle/basset-mix who has a persistent itching/scratching/biting problem.

My cocker spaniel had the same problem a number of years ago. She was chewing herself apart. All four of her legs were chewed down to raw meat -- bleeding, filled with ugly sores and pus, and scaly.

I was at my wit's end watching our beloved pet suffer so much. Her vet didn't know what was causing the problem. I spent a small fortune on medications and shampoos that did nothing to help her. She was unable to sleep, and I would sit up with her, bathing her legs in milk to try to give her some relief.

One night when my husband and I were having dinner, he happened to mention that his boss had gone to the doctor because she was not feeling well. She had a rash and was breaking out with lesions. She learned that she was allergic to an artificial food colorant called Yellow No. 5.

While contemplating what my husband had just told me, it occurred to me that our cocker spaniel could have the same problem. I immediately pulled out her food and treats and started checking the ingredient labels. They were loaded with artificial colorants: Red No. 3, Red No. 40, Yellow No. 5, Yellow No. 6, Blue No. 1 and Blue No. 2. I threw out all of her food and started her on new foods and treats that were all natural and had no colorants added.

By that evening, I noticed my dog was not biting and scratching as frequently, and she was able to get some sleep. By the following day, I noticed that she was not biting or scratching at all. Within two weeks, her sores healed, the scales were gone and her fur started to grow back.

I hope you will pass this information on to your readers, and advise them the check labels for colorants. Pet owners must be informed and alert as to what we are feeding our loved ones. It disgusts me to see what the animal food industry has done to our beloved pets. Pharmaceutical companies and veterinarians are also to blame for medications that are killing our animals. Pets and their owners deserve better than this; it's unfortunate that we must learn through word of mouth or trial and error.

Please keep up the work you are doing. I enjoy reading your column every week. -- C.R., Monroe, Conn.

DEAR C.R.: I give your letter five stars for its importance in identifying a significant health issue for all consumers, animal and human, concerning the use of coloring agents in various consumables. The United States government, long under the thumb of the chemical, food and beverage industries, has yet to act responsibly with regard to the various dyes used in manufactured foods. Some are prohibited in Europe because they are classified as carcinogens. Some may play a role in attention deficit hyperactivity disorder in children and may cause seizures in epilepsy-prone dogs. I know of one dog who would have a seizure if given even a small piece of yellow or red cheese -- the natural dye from the tropical "lipstick," or achiote, tree, called annatto, being the culprit. There is a possibility that there was another ingredient in one of the treats or dog foods that caused your dog to develop these distressing allergy or hypersensitivity symptoms, but that would cost a small fortune to identify, and your common sense solution worked.

American pet owners, parents and consumers: Wake up!

DEAR DR. FOX: My daughter has a rescued female pit bull mix. She is a wonderful dog who was trained by the prison dog program in Florida.

The dog has developed a rear leg limp suddenly, and it is obviously painful. The veterinary school at the University of Florida made a diagnosis of detached tendons in both legs. The only solution they offered was surgery -- for $7,000. There is no way my daughter can afford that. She is beside herself. Help! -- B.W., Naples, Fla.

DEAR B.W.: This is a very prevalent affliction, in part related to the angulation of the hind legs, the weight of the dog, that age at which she was spayed and possibly an adverse reaction to distemper vaccinations. For details, see my review in my book "Healing Animals & the Vision of One Health."

The surgery fee at the veterinary college is exorbitant. Your daughter should get price quotes from private veterinary practices, some of which may arrange for payment by an installment schedule.

Smaller, lightweight dogs can get by without corrective surgery, but I see little alternative for an active, muscular dog like your daughter's, unless her weight and strenuous physical activity are kept under control and she is given a daily treatment of massage and physical therapy. Give it a try over a rigorous six- to eight-week period, and provide good joint-supportive supplements such as Cosequin, turmeric and fish oil.

(Send all mail to animaldocfox@gmail.com or to Dr. Michael Fox in care of Universal Uclick, 1130 Walnut St., Kansas City, MO 64106. The volume of mail received prohibits personal replies, but questions and comments of general interest will be discussed in future columns.

Visit Dr. Fox's website at DrFoxVet.com.)

DEAR DR. FOX: Do you have a homeopathic cure for cat dandruff? I have two beautiful 8-year-old brothers who have developed dandruff suddenly. There has been no change in their environment or diet. Thanks for any advice you may have. -- S.K., Highland, N.Y.

DEAR S.K.: There are many reasons why cats and dogs develop dandruff. In some instances, it is coupled with fur shedding, and not to be an alarmist, it can be an early indication of a serious health problem. But it is a fact that the shedding of skin flakes and fur is a cyclical process that can intensify in winter, when the animal's environment is typically low in humidity.

Cats enjoy sunbathing, which may benefit their skin, so providing carpeted window shelves that get sunlight may be advisable.

Poor skin and coat condition are often associated with omega-3 fatty acid deficiency, especially with dry food diets. A few drops of fish oil may solve your cats' problem, especially since they are eating the same food.

You say there has been no change in what they are fed, but pet food ingredients under the same brand can change. Also, it can take many months for nutritional deficiencies to develop. Since your cats are middle-aged, a full veterinary checkup is advisable, including testing for thyroid function if omega-3 supplementation does not improve this condition after six to eight weeks.

DEAR DR. FOX: I have read that diatomaceous earth can be used to rid horses, cats and dogs of worms. What is your opinion? -- E.L., Fort Myers, Fla.

DEAR E.L.: Food-grade diatomaceous earth is the only form of this product that should be used externally on the animals' coats and as a dust around the house to control fleas and even bed bugs. The pool-grade is dangerously high in silica, which could cause lung damage.

Diatomaceous earth, given orally for several days, has been shown to eliminate various internal parasites, such as whipworms, roundworms, hookworms and tapeworms. The effective dosage is 1 teaspoon per 10 to 20 pounds of body weight mixed in with food once daily for 60 to 90 days -- though 30 days of treatment may suffice. This product is harmless and can contain some beneficial trace minerals. I would like to see a peer-reviewed report of clinical trials on it.

There are other natural products with various medical qualities that are being rediscovered. Silver -- in colloidal form -- can be used to enhance the action of existing antibiotics against gram-negative bacteria, thus strengthening the antibiotic arsenal for fighting bacterial infections. Clay also has antibacterial properties, and can help in the treatment of inflammatory bowel conditions.

(Send all mail to animaldocfox@gmail.com or to Dr. Michael Fox in care of Universal Uclick, 1130 Walnut St., Kansas City, MO 64106. The volume of mail received prohibits personal replies, but questions and comments of general interest will be discussed in future columns.

Visit Dr. Fox's website at DrFoxVet.com.)