Q: For the past several months, my cat, Rudy (a 15-year-old shorthair male, neutered), and my mother's cat, Ebony (15-year-old Persian, spayed), have been experiencing constipation. Both were given over-the-counter hairball/laxative lubricants, and both were taken to our local vet for a soap-and-water enema and IV hydration.

However, the problem continues to occur, with minimal to moderate success with the lubricants. Rudy is also given fiber in his diet (prescription capsule poured on soft food.) Both cats eat soft canned food and dry food. Recently, the constipation has been more difficult to treat in my mother's cat. I have been lubing Rudy every three or so days. My mother has been lubing Ebony with a small amount daily.

A: Chronic constipation can be quite a serious problem in the older cat and difficult to treat. One of the conditions that can arise from chronic constipation is the more serious mega-colon. This condition results from prolonged distension of the colon due to chronic retention of fecal material, resulting in irreversible changes in colonic motility leading to inertia of the colon. It is important to make sure the diet is high in fiber. Hill's produces two special diets - t/d and w/d - for such eventualities. Unfortunately, none of my cats would eat it. Most cats will eat and like pumpkin pie filling; this is a good source of fiber and can be added to their wet food. Try to feed mostly wet food rather than dry food and encourage the cats to drink plenty of water, as dehydration can make constipation worse.

Unfortunately, common hairball laxatives do not work well in treating constipation, but the stool softener Colace has been reported to be beneficial. The drug cisapride given 30 minutes before feeding has had some dramatic results in some cases; your veterinarian will be able to advise you on its use. It might be possible to try it for your mother's cat under veterinary supervision. In some cases, glycerol suppositories can be used in preference to enemas.

I have an 18-year-old cat who loves milk and, like most older cats, he is lactose intolerant, so this results in a very loose stool, so that might be something you could possibly try on a limited basis. He has it as a treat on weekends. But give only a small amount, or it results in diarrhea.

Q: Our family pet is a middle-aged boxer who has a very unfriendly problem. She has a lot of gas, which is incredibly smelly. It seems to happen in the evenings when she is asleep and we are watching TV. Sometimes it's so bad that we have to open the windows or leave the room. What can we do? I don't want to banish her from being with us. I do shut her away when we have guests, as it can be embarrassing.

A: Unfortunately, many dogs seem to have a gas or flatulence problem. Most cases can be reduced, if not cured, by changes in the diet. Initially, I would recommend that she have an examination by your veterinarian to rule out any serious intestinal problems. Chronic gas can be a symptom of pancreatic disease or intestinal problems such as irritable bowel syndrome or parasites.

Once these problems have been ruled out, the problem is often found to lie with the type of food being fed. Dogs are basically carnivores and do not digest carbohydrates well. Diets that have a high carbohydrate content, such as the cheaper commercial dog foods, can cause gas problems as they ferment in the gut. A dog's gastrointestinal tract is deficient in the enzymes needed to break down the indigestible fiber and complex carbohydrates present in these diets. As the carbohydrates ferment, they produce a variety of gases including methane and hydrogen sulfide. These are responsible for the terrible smells so often produced.

The first thing to do is to change to a high-quality dog food rich in animal proteins. Be careful that the food does not include a high liver content, as that can sometimes cause a problem by being too rich.

Plenty of regular exercise will help to keep your boxer regular, by promoting stool elimination and gas at the same time. However, do not indulge in vigorous exercise just before or just after a meal. Feeding your dog two or even three smaller meals a day often works in many cases, leaving several hours between meals to allow for complete digestion. Do not leave food down for your dog to free-feed. Some dogs bolt their food and in doing so swallow a lot of air; this leads to burping and gas passing. To slow down the pace of eating, put a large clean stone or half brick in the feeding bowl so that the dog has to eat around it.

Some owners claim that feeding charcoal biscuits in the evening meal cuts down on the amount of gas produced, as the charcoal absorbs it. Another home remedy is fennel. Grind the seeds and make a tea, using one teaspoon of ground fennel seeds with 8 ounces of boiling water. The dose is half to one teaspoon of the cooled tea added to the food, although some dogs are happy to lick it off the spoon. Keep the remainder in a closed container in the fridge for future use.

Dr. Jill Bowen has practiced veterinary medicine in England and Texas and taught at Texas A&M. She lives with her veterinarian husband, three cats and a chocolate Labrador retriever in Blacksburg. If you have a question, please write to her in care of The Roanoke Times' New River Current, P.O. Box 540, Christiansburg, VA 24068, or send an e-mail to mjbowen@radford.edu. Jill Bowen regrets that she cannot answer readers' letters personally. All sick animals should, of course, be taken to a veterinarian.