Dear Matthew: We own a 3-year-old cat named Alexander. Recently, my wife and I went on a spring vacation and had a friend come over and look after the cat while we were away.

When we returned back to our house, we discovered that Alexander was no longer using his litter box. We asked our friend if she did anything to upset Alex, but she said she just fed him and spent some time petting him. What's going on? If this is going to happen every time we leave town, it's going to become a real pain.- Jon in Trenton, N.J.

Dear Jon: There are a number of reasons why your cat may no longer be using his litter box.

It could be that the area became too dirty while you were away. Did your friend change the litter, or did she just feed Alexander? If that's the problem, then a thorough cleaning of your cat's box and a few days for things to settle down should be all that's required.

Another possibility is that your absence, coupled with the regular presence of your friend, upset Alexander's daily routine enough that he stopped using his box. Cats are creatures of habit, and they don't take too kindly to changes in their environment. So, if this is the case, once things get back to normal in your house, Alexander should snap back into line.

Whatever the cause, you should thoroughly clean and disinfect the areas Alexander has soiled, so he won't be encouraged by the scent to return to the same spot again.

Finally, if your cat's litter-box difficulties continue, it could be due to a medical condition such as a urinary-tract infection. If more than a week or two goes by and your cat doesn't change his ways - or if he starts showing other signs of illness, such as a fever, listlessness or excessive shedding - you should consult a veterinarian.

Dear Matthew: My turn to insert my "two cents' worth" concerning the ongoing Jack Russell terrier controversy. Let me tell you what we "got into" when we made the Jack Russells our breed of choice.

We bought our first J.R., a female puppy, when our daughter was just 2 years old. Last summer, we purchased a second J.R., a male puppy. My daughter was 4. Sure, the dogs have very active metabolism - and my daughter does, too. But the dogs are also very loving and gentle. When playtime is over, their favorite place to curl up is with our little girl. And I dare say they would lay down their lives for each other.

My sister has a male J.R., as well, and we are friends with many more of these tremendous little dogs. Granted, there may be Jack Russells that would not fit into a family with young children, as there would be individuals of any breed. But I do know my dogs would be extremely bored without their 5-year-old "master," and she couldn't live without them, either.

Those of you out there who have desired to "be owned by" a Jack Russell terrier, don't be discouraged. We have never been sorry we made this choice. And now, no breed comes close to matching their love, beauty, extreme intelligence and endless entertainment that they have given us with their wonderfully crazy minds. They steal your heart, totally!

- Diane in Gillett, Wis.

Dear Diane: I'm glad to hear you've had such a good experience with your pets. Jack Russells can be everything you describe, although they aren't perfect for everyone.

These dogs require a good deal of attention and care to keep them happy and healthy. If you don't give them enough exercise and train them at a young age, you could be unleashing a canine tornado on your home.

People who want to own Jack Russell terriers - like people interested in getting any breed of dog - should do the research and put a serious effort into making sure they're ready for the responsibility and demands of owning a pet.

After all, bringing home a dog is adding a new member to your family for years and years to come.