DEAR DR. FOX: My wife and I have a 5-year-old bichon frise whom we adopted three years ago. He idolizes my wife and has from day one. We think that in his prior home a male mistreated him, as he has always been wary of me, if not downright aggressive. He has gradually warmed up to me, but he still isn't as close to me as he is to my wife.

We have a new grandson who lives out of town. When my wife went to visit him, we began having problems with the dog, who has slept in our bed with us from the beginning. He has become territorial -- to the point that if I get up in the middle of the night and get back into bed, he growls or lunges at me. Now, even when my wife is in bed with him, he will do the same thing, sometimes if I am only walking by the bed.

I have tried leaving a light on in a nearby room and talking to him before I get into bed. Neither solution is foolproof. The problem is intermittent, and we can't figure out what triggers it. During the day, when I am working at home and my wife is at her job, he is affectionate. But the nighttime attacks are getting wearisome and more frequent. Any suggestions? -- D.S., St. Louis

DEAR D.S.: You have my sympathy having to share the bed with this territorially aggressive canine upstart! He is exhibiting location-specific dominance-aggression.

In the old days, the approach would be to put on protective clothing and gloves, and when the dog lunges at you, pin him down firmly, and don't let him loose until he submits and stops struggling. Contemporary behavioral therapists would suggest basic obedience school to teach your dog to sit and stay and to establish you as the top dog giving the orders.

Buy a dog-training clicker or use a can of coins to condition your dog so that with one click or shake, he gets a reward. Do this first in the living room, and once he's conditioned, do it when he's on the bed. This will re-motivate and redirect his behavior from threatening to expecting reward.

What is your wife doing? If she is the boss, she should order the dog off the bed. Shunning is a potent form of canine -- and human -- discipline.

You might also try re-motivation using a squeaky toy, inviting your canine delinquent to play and catch the toy rather than attack you. Finally, a short term of treatment with melatonin or a psychotropic medication like Prozac, under veterinary supervision, may be your final solution.

DEAR DR. FOX: Two years ago, my son brought home a homeless kitty. She was so affectionate, especially toward my son, that we fell in love with her. Now she is a member of our family. We named her Lucy.

My son went abroad for a year, and since his return Lucy has become aggressive toward him. She swats his feet when he walks near her and hisses at him when he talks endearingly to her. Why the change in attitude toward my son? And what can he do to gain Lucy's affection again? -- B.C., St. Louis

DEAR B.C.: Lucy has become accustomed to living in your home without the scent, sight and sound of your son. All these unfamiliar stimuli can trigger fear or sudden defensive aggression.

I would advise your son to not force contact with Lucy; let her come to him. If she likes to be brushed, he should do so, and he should be the one to set out her food and clean out the litter box.

Lucy's ambush attacks could be attention-seeking play behavior rather than pure aggression. At times she is most active (early and late evening for many cats), have your son engage in interactive play using a long cane with a fluffy toy tied to a string that's secured to the end of the cane. My two cats love this game, and one of them also chases a laser pointer light across the floor, which Lucy may also enjoy.

DEAR DR. FOX: I have a 16-year-old female Persian cat who started pooping everywhere. I gave her a new litter box, but it did not help. Then one day, I decided to hide her litter box under a big desk, and I put a cover over the entrance.

Now she uses the litter box exclusively. Wow, who knew she wanted privacy when she pooped? -- S.E.B., Norfolk, Va.

DEAR S.E.B.: As I detail in my book "Cat Body, Cat Mind," there are many reasons why cats poop outside of their litter boxes. The most common reason is chronic constipation, especially in older cats.

A less-common reason not always considered is precisely what you have discovered. Some cats like privacy, and I always advise putting litter boxes in low-traffic spots in the home. It is natural for animals to feel vulnerable when pooping. One of my dogs would always choose to hide in the bushes to poop rather than do it by the side of the road so I could easily pick up.

Getting old, losing eyesight and hearing and painful arthritis in the back can make cats have difficulties evacuating. Give your cat a few drops of fish oil in her food every day, and give her a good evening massage along her back and around her abdomen.

(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 www.twobitdog.com/DrFox.)