I receive many inquiries about how effective certain herbal and homeopathic products are, along with letters singing these products' praises -- some of which I feel may come from unscrupulous marketers. My basic advice is to first consult with your veterinarian. Then, go on the Internet and see what kinds of consumer reviews are posted, if there are no peer-reviewed clinical studies published. If you find any of the latter, share them with your animal doctor. Check my website, drfoxvet.com, for some effective and safe products for various conditions. All products should clearly list the ingredients.

I do not have the resources to help pet owners through the process of trying out these many products being marketed, and it is my sincere wish that more clinical trials would be conducted by veterinarians in full-time companion animal practice, and by veterinary college departments of small-animal medicine. I have, for instance, heard that cats with kidney disease have benefited from Azodyl, a dietary supplement, and both diabetic cats and dogs from Blood Sugar Gold, an herbal extract/tincture. But I have no hard, published evidence or confirmation from veterinarians to unconditionally endorse these and other products -- much as I would like to, if they are indeed safe and effective. My final word: Discuss any new products with your veterinarian, and try them with caution if your animal doctor believes that they should, at least, do no harm.

DEAR DR. FOX: My son got me a Yorkie last May. The dog is less than a year old. I am handicapped, and he is hyper and constantly barking.

Is there anything I can do? I love him, but don't like his behavior. He is about 10 lbs. I had a Yorkie several years ago that was small, and the most wonderful dog you could have. This dog is hard to understand or try to teach anything. He is so strong-willed. Please help! --P.L.

DEAR P.L.: I presume that your son is a caring person, and not just giving you a dog as a substitute for him visiting as often as he can. If he were better informed, he would have found you an older dog, not a young one who is physically active and probably gets easily bored when not engaging in various activities.

All being well, as the dog matures in a year or so, he will calm down. But right now, he needs lots of stimulation that you must provide to whatever degree you can, considering how severe your physical handicap may be. Call in a dog trainer to teach you interactive games and how to reward him for not barking, which he probably does for attention. If you can't walk the dog and get him outside for off-leash running and exploring in the yard or a safe dog park, hire someone to come over at least once a day. Maybe your son could help, too.

Good luck to you and your young dog.

DEAR DR. FOX: I know how hard it is to try and diagnose an animal without a physical examination, but I really need an opinion, however general. I cannot afford to take my cat to the vet, as I am 76 and on a fixed income.

My problem involves a cat that I have kept for many years, after my granddaughter couldn't keep him. He is an indoor cat, never been out, always healthy and sleek with a good appetite.

I noticed during the winter that his water bowl was always nearly empty, abnormally so. He didn't used to be overly fond of wet food, and ate a lot of dry. Things have lately reversed and he is craving wet food, and seems ravenous for any kind of food -- my dinner, anything he smells -- and he is losing weight. He doesn't seem in any pain, sleeps a lot, purrs when he sleeps near me at night, and he is still active, jumping on the sofa, etc. I am tempted to just let nature and age take their course, as long as he isn't vomiting or bleeding, etc.

Could he have diabetes? If he were an outside cat, I would suspect a tapeworm, but I examine his stools and they look normal. If you could advise, I would so greatly appreciate it. -- L.W., Asbury Park, N.J.

DEAR L.W.: You and your cat have my sympathy. Such ravenous appetite and weight loss can be due to a number of disorders appearing in middle-aged and older cats.

A hyperactive thyroid gland, often combined with diabetes and possibly kidney disease and some form of cancer, is the kind of thing a veterinarian would first check your cat for. The diagnostics and likely treatments will not be cheap.

If your community has an animal shelter or humane society, call and see what kind of financial support may be available. Some veterinarians offer discounts and set up installment payments for services.

The alternative is to make life as comfortable as possible for your cat. Make big batches of my home-prepared cat food (on drfoxvet.com), and give him 5-7 very small (1 tablespoon) meals of moist food and all the dry food he wants. Also give him daily pinches of organic catnip, available in pet stores, which most cats enjoy immensely; you can even get live plants in some garden supply stores and nurseries. In the evening, give him 1 mg of melatonin, available over the counter in drug and health stores.

(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: We have an adorable 9-year-old dachshund named Max. We give him dry food mixed with some moist commercial food, as well as carrots or string beans.

Lately, he's been having diarrhea once or twice a week. My son also gives him half a slice of American or Swiss cheese. Could that cause his problem?

To curb his diarrhea, I give him some raw chicken with rice for a day or two, but the problem still comes back.

What do you suggest? -- A.T., Gainesville, Va.

DEAR A.T.: If your dog has an episode of diarrhea within a few hours of being given cheese to eat, then that is the logical cause of his digestive upset. Many dogs are allergic or hypersensitive to casein (a milk protein) in dairy products. The yellow coloring agent used in many cheeses is called annatto, and it comes from a tree called the lipstick tree. A small piece of yellow cheese will make some dogs have a seizure. You should read the labels on the manufactured dog foods you feed him and eliminate those containing any dairy products.

If his periodic episodes of diarrhea persist, he could be reacting adversely to other ingredients, such as beef, eggs, wheat or soy. So consider a balanced rice-and-lamb-only diet or prepare your own dog food from known ingredients, as detailed in my book "Dog Body, Dog Mind," or on my website, DrFoxVet.com.

A veterinary checkup of his stools to rule out parasites and bacterial infection or chronic pancreatitis would be prudent if this has not yet been done.

DEAR DR. FOX: My vet says he's been a vet for many years, but this is the first time he has encountered this one:

When Maxine, our spayed female indoor calico cat, finishes covering up her business, she becomes very possessive of her accomplishments. Soon after, when we are cleaning out her potty, she will strike out with claws at our hands and legs. We wonder if she feels that we are taking something of value away.

She has reacted this way for the nine years we have had her. We protect ourselves by closing the bathroom door. However, sometimes we find her waiting for us on the other side. -- W.K.Z., Naples, Fla.

DEAR W.K.Z.: Our formerly feral cat hisses when he sees me carrying the litter box out to be cleaned. I interpret his reaction as fear of something looming over him. When he is in the litter box and is disturbed, he bolts, which I think is an indicator of his sense of extreme vulnerability in that situation. Your cat's reaction is both unique and bizarre.

Animals are vulnerable when they are evacuating and, therefore, need a quiet spot to do their business. My interpretation of Maxine's behavior is an extension of this observation -- your "invasion" of her private toilet space triggers a defensive-aggressive reaction.

Other interpretations of Maxine's unusual behavior from readers with "inner cat wisdom" would be welcome.

(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 response to a letter in your column regarding the hypersensitive cat in Fort Worth, Texas.

My 3-year-old female longhaired cat is an indoor cat who longs to spend time outside, which we supervise. The only time she allows me to brush her is when she is sitting on my legs outside. As long as she is outdoors, I can brush her as long as I want. -- C.W., Olney, Md.

DEAR C.W.: Cats are curious creatures in that they react differently depending on where they are. This place-determining trait is indicative of their awareness and sensitivity to certain stimuli, to which we may be insensitive, but which provide some insight into our cats' behaviors.

Outdoors, your cat may be more relaxed and does not feel threatened by the intense stimulation of being groomed by you. This is an invasive experience for many cats who require time and patience to enjoy being groomed and managed. Indoors, your cat no doubt feels confined, and she may therefore resist holding and brushing. You should also consider static electricity being generated indoors while grooming your cat, which can be discomfiting. Grooming and brushing on a cotton sheet or towel rather than on a synthetic material that quickly generates static electricity may be worth a try. You could also use a moistened brush.

DEAR DR. FOX: You may have already addressed this in your column, but I believe it bears repeating: Xylitol, a sugar alcohol, is DEADLY to dogs. I know this from firsthand experience. Luckily, our dog pulled through, but it was because of fast action.

Late on a Friday night last August, as we were getting ready for bed, one of our Shelties, Buddy, got into a pack of sugar-free Tic Tacs. Within 10 minutes, he vomited, couldn't stand up and was shaking. I called our Animal Emergency Clinic and rushed him there. They said his blood sugar was dangerously low, so they administered two IVs -- one of glucose and one of saline. They kept him for 48 hours. His liver enzymes were rechecked and had dropped from more than 900 to 204. We will be checking them regularly.

Please put a warning in your column from time to time. People react with "Really? Tic Tacs did that?" Xylitol is in most sugar-free chewing gums, too. -- J.M., Cedar Hill, Mo.

DEAR J.M.: Many readers will appreciate your letter of warning regarding the highly toxic effects of widely used artificial sweeteners when ingested by dogs.

Xylitol triggers acute lowering of blood sugar by stimulating the release of insulin from the pancreas. Doses in excess of 1 gram per four to five pounds of body weight cause liver damage.

Gastric lavage (stomach pumping) may be helpful if the dog has recently swallowed xylitol-containing confections or chewing gum. Xylitol in baked goods remains toxic to dogs because it is not deactivated by heat.

DEAR DR. FOX: I know how hard it is to try and diagnose an animal without physical examination, but I really need an opinion, however general.

I cannot afford to take my cat to the vet as I am 76 and on a fixed income. My problem is a cat that belonged to my granddaughter, whom I have kept for many years as she couldn't keep him. He is an indoor cat, always healthy and sleek with a good appetite.

I noticed during the winter that his water bowl would be almost empty, abnormally so. He wasn't overly fond of wet food, and he ate a lot of dry. Things have lately reversed. He is craving wet food and seems ravenous for any kind of food, including my dinner. He jumps up to where I am eating and tries to lick my plate, which has odd foods he never tried to eat before and that a cat wouldn't normally like -- salad oil, spaghetti, etc. He jumps on the covered garbage pail and knocks it over because he smells scraps. I now feed him wet food twice a day, and always keep a bowl of dry food available for him. As much as he eats, he is losing weight. Over the past three weeks, it is very noticeable how thin he is getting.

He doesn't seem to be in any pain. He sleeps a lot, purrs and is still active, jumping on the sofa. I am tempted to just let nature and age take its course, as long as he isn't vomiting or bleeding. He could he have diabetes. If he were an outside cat, I would think tapeworm, but I examine his stools, and they look normal.

If you could advise, I would so greatly appreciate it. -- L.W. Asbury Park, N.J.

DEAR L.W.: You and your cat have my sympathy. Such ravenous appetite and weight loss can be due to a number of disorders appearing in middle-aged and older cats.

A hyperactive thyroid gland often combined with diabetes and possibly kidney disease and one form of cancer or another are the kinds of diseases a veterinarian would first check your cat for, and the diagnostics and likely treatment will not be cheap.

If your community has an animal shelter or humane society, call and see what kind of financial support may be available. Some veterinarians offer discounts and set up installment payments for services. The alternative is to make life as comfortable as possible for your cat: Make big batches of my home-prepared cat food (on my website, DrFoxVet.com), and give several very small meals of moist food and all the dry food he wants. Also, give him pinches of organic cat nip, available in pet stores, which most cats enjoy immensely. In the evening, give him 1 milligram of melatonin, available over-the-counter in drug and health stores.

(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.)