DEAR DR. FOX: Today's Palm Beach Post has an article about a study of the effects of mixing chlorine with pee in pools. As it turns out, many people do urinate in pools. Apparently, the combination of uric acid and chlorine causes a chemical reaction. The dangerous gas cyanogen chloride is the result, which can harm the central nervous system, heart and lungs.

I thought of cat and dog owners who clean up accidents and litter boxes with bleach. I use white vinegar to clean up after my cats and used club soda as the immediate cleaner after my dogs' accidents. Perhaps you could look into this and give a warning to all your readers and pet owners. -- B.C., Palm Beach, Fla.

DEAR B.C.: Thanks for waving the red flag to minimize a possible risk from improper use of chemicals in the home environment. I NEVER suggest using bleach to clean things around the house, and especially for disinfecting various dog and cat urine and fecal deposits in and around the home. This fairly new information about the interaction of urine with chlorine in swimming pools underscores the hazardous nature of chlorine bleach products, which are also implicated in ozone layer destruction and endocrine system disruption. Safer enzyme cleaners, white vinegar and baking soda should be used in the home. Many people have died from inhaling mixtures of cleaning and disinfecting agents such as bleach with ammonia.

DEAR DR.FOX: I have two 10-year-old Devon rex altered female cats. They were born on the same day, but they are not littermates. They are very different in looks, size and temperament, but they get along well. They have always been very affectionate with us and others. They are indoor-only cats, have no fleas and are fed both wet and dry food.

Several months ago, the usually outgoing tortie began to groom her lower back a lot and would warn you if you tried to touch it. The vet said that many cats do not like to have their lower backs and tail area touched, but she had never minded before. Last week, she actually bit my husband while in her frantic grooming.

I began a Google search and believe that she is demonstrating the symptoms of hyperesthesia. We moved several times last year and have settled in Florida. We have had a lot of renovations done in the house and think maybe all the changes, noise and extra people in the house may have overstressed this normally pleasant cat.

She now has a bald spot on her back, and we have an appointment to see the vet again next week. We don't know how to help her stop the grooming. What can we do for this much-loved member of our family? -- P.M., Sanibel, Fla.

DEAR P.M.: You must first rule out hyperthyroidism, which is common in older cats and can be precipitated by stress when the thyroid gland is already compromised. One of the symptoms can be hypersensitivity to touch and obsessive-compulsive grooming. Another possibility, especially where there is much humidity, is a malassezia fungal infection.

In the interim, see if the cat will eat or drink a tea made from catnip that can act like Valium and have a calming effect for a few hours. Try a half-teaspoon of good-quality catnip, available in health stores. Some folks make a tea of it for themselves before bedtime. Another treatment could be one milligram of melatonin in the cat's food daily.

A possible food allergy, which could have been brought on by a change in the ingredients in the cat's usual food, should also be considered. Regardless of the same brand name, changes in ingredients from batch to batch of manufactured pet foods can pose problems. For more details, check my website, DrFoxVet.com.

(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: This isn't really a question, but it does concern the animals. I appreciate your advocacy of spaying and neutering to control pet overpopulation, as well as what you say about the huge farm-animal population and the need to reduce our consumption of animal produce. But what about the ever-increasing human population? -- L.E., Alexandria, Va.

DEAR L.E.: The human species is the worst of all planetary infestations! Human population control, through famine, disease and war, are ancient, arguably biologically natural and ecologically remedial correctives. Costs notwithstanding, pharmaceutical, surgical and educational components of family planning face enormous obstacles, cultural and political. Having many children provides cheap labor and economic security in some cultures. Politics are rarely divorced from corruption and the kind of disinformation that equates family planning with genocide.

There is a delicate balance between stabilizing populations through the economic security of technological industrialization and sacrificing cultural and biological diversity. If the wisdom of America's 19th-century natural philosopher Henry David Thoreau -- "That in wildness is the preservation of the world" -- is incorporated by all who are dedicated to improving the human condition, the relentless conversion of the natural world into a bio-industrialized wasteland may be averted.

Effective advocacy of population control through family planning is to be applauded. Opponents who make fatuous religious and moral claims such as the right to life of the unborn live in denial of the severity of the human infestation and its environmental, economic and health impacts on a planet of finite resources, and, in the process, bring more suffering into this world.

DEAR DR. FOX: Almost 10 years ago, a cat wandered into my parents' yard and had kittens two weeks later. I ended up taking in the mother, Kitty, and a daughter kitten, Dora. Until recently, I thought I had the best cats -- sweet with nice dispositions. I always felt so lucky.

A couple of months ago, Kitty started hissing at Dora. It went on for about three weeks, when I decided to take her to the vet to check on medical issues, since that's what most articles I read recommended. The vet did blood and urine tests and found that she had an ear infection, but the tests came back fine. I gave Kitty the prescribed eardrops. Within four days, things were back to normal, and they were once again snuggled up sleeping next to each other. On the fifth day, Kitty was sneezing a lot. I took her back to the vet. She had an infection. I opted for a shot because I was nervous about how well she would take medications from me. By that weekend, she was really sick. I took her back to the vet on Monday. She was given stronger medicine, and this made her better.

Then Dora came down with a respiratory infection. I took her to the vet, but this time I opted for oral antibiotics since they would be stronger. It was a nightmare trying to give her the meds. After two days, I tried a pate-style cat food, crushed the medicine and mixed it in. That seemed to work. But Kitty went back to hissing, and Dora started hissing and growling.

I took Kitty back to the vet again. The ear infection had not completely cleared, so she was put on eardrops for another 10 days. Sadly, the aggression escalated when I was at work. They must have had a fight -- there were tufts of fur around, and I found small tufts of fur under their claws. That night there was another incident.

Now I separate them when I'm not home and at night when I go to bed. Things are not getting better. I make sure they are not near each other to fight. Dora seems particularly traumatized by all of this. She is fine with me if Kitty is locked up, but she's skittish and a bit nervous. I hope you can assist in guiding me in the right direction. -- K.D., Brick, N.J.

DEAR K.D.: I am so sorry to hear about all the stress in your life dealing with sick and fighting cats. Your reaction to all the stress is probably also affecting your cats, creating a vicious cycle. Don't feel bad about that.

How and why the older cat developed an ear infection is a mystery -- thought it could possibly be an adverse food reaction. Any such discomfort can lead to defensive, aggressive behavior. You were wise to take the cat to the veterinarian. In the future, do try to get an in-home visit, especially for cats who may pick up respiratory infections even in well-run veterinary facilities.

One way to break the aggressive reactions of Kitty toward poor Dora is to try the plug-in pheromone called Feliway. Put this in the room with Kitty and in the room with you and Dora. Get a moist cloth and rub it on both cats repeatedly so they pick up each other's scent. Offer both cats good-quality dried catnip to eat -- I call it cat Valium -- then after they have eaten or smelled and rolled in it and you have rubbed some under their chins, let them be together briefly. Repeat this on a daily basis and be calm and quiet. Have a towel or pillow on hand to put between them to stop any attacks by Kitty.

If these steps do not help, she may need to have a thyroid function test done, since hyperactive thyroid disease can lead to temperament changes, increased irritability, self-grooming and ear and skin infections.

(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: A close friend has a police dog (a German shepherd, bred in Germany for that purpose) with severe health issues.

The major problem is pancreatic enzyme deficiency. His vet has him on pancreatic tabs, but he still has loose stools, is very thin and his coat is dry and lackluster. He also has recurrent ear infections, but I think that is a separate issue.

Is there a natural diet or any type of supplements that could help this wonderful dog? -- C.C., Fallon, Mo.

DEAR C.C.: This is a very prevalent issue for German shepherds, which used to be confused with chronic colitis associated with stress and sensitive temperaments. Chronic disease of the pancreas, producing insufficient digestive enzymes, is a problem more common in certain breeds like your friend's dog and is thought to be a kind of exhaustion due to having to digest a high-carbohydrate diet.

I would advise that the dog be gradually transitioned -- over five to seven days -- onto a grain- and soy-free diet, digestive enzymes (a few pieces of canned pineapple will provide these), plus a twice-daily human dose of good-quality probiotics and a few drops of fish oil to provide essential fatty acids to help improve the dog's coat and overall condition.

Check my website for more details. Let me know how the poor dog progresses.

DEAR DR. FOX: Why do some dogs chase cars and others howl when they hear the tornado test siren? I live in a rural area, and these dogs drive me mad. I have a dog who does none of these things, and I am the only person around who walks him on a leash. Most are chained up or let out to roam. -- I.M., Galesburg, Ill.

DEAR I.M., The answer to both questions is instinct. Dogs chase vehicles and kids on bicycles, which can be a hazard, as a displaced prey-chasing activity. I know of some vehicle-chasing country dogs, along with turtles and any creature on the road, being deliberately run over by some drivers.

People in rural areas should take responsible and appropriate care of their dogs, which means not letting them roam free or live most of their lives on a chain. There is a disturbing undercurrent in rural America of animal, child and spousal abuse -- all connected -- which calls for the ethical revival of a civilization in decline. Living in Minnesota, I am shocked that thousands of mainly rural people apply for permits to shoot wolves and other "trophy" species as a recreational sport.

PET POISONING INCIDENCES

Human prescription drugs came in first place in a recent report on the Top 10 pet poisons in 2013, ranked by call volume to the Animal Poison Control Center. Insecticides took second place, followed by over-the-counter drugs for humans; household products; human food (such as onions, garlic, grapes, raisins, chocolate and the sugar substitute xylitol); veterinary products and drugs; chocolate; mouse and rat poison; plants and lawn and garden products. Antifreeze, long overdue for manufacturers to add pet-repelling additives, continues to be problematic, as dogs are attracted to its sweetness. Note: macadamia nuts, bread dough and avocados may also harm animals.

(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.)