If you share your private life with a cat or dog, do your pet a favor: Find out what you should know about emergency veterinary care before you need to know it.

If you wait until the awful evening Rover is hit by a car, or the Sunday morning Felix has a urinary tract blockage or -- as I did -- the Saturday afternoon a miscreant with an air pistol decides kittens make more challenging targets than tin cans, you could be in for some surprises. And more waste of time than you and your ailing pet can afford.

Don't assume the "after these hours -- emergencies only" sign in the waiting room means your vet is always, or often, available in an emergency. Find out.

More and more house-pet vets these days are freeing their private lives and cutting down on overhead by leaving after-hours care to one of three non-competing, consortia-owned, after-hours only emergency clinics that ring the Beltway.

And more and more often, an evening, holiday or weekend call to a vet will reach only a recording -- a recording that seems to go on endlessly about normal hours and appointment procedures before directing you to one of the emergemcy clinics.

If you live within easy driving distance of Rockville, Vienna or Glen Dale and patronize a veternarian who practices nearby, you should have no problem.

But if you and your vet are in different neighborhoods -- especially in the District, where the closest of these clinics may be 25 minutes away with good driving conditions and good dirrections -- the difference between your vet's and your convenience easily could double the driving time.

Obviously, when an animal is fighting for its life, that can be crucial. And getting better information after dark or after noon on Saturday can be amazingly difficult.

The SPCA or Humane Society, if you give them your location, can tell you in a flash where to find the nearest reduced-rate spay/neutering clinic. Byt they do not keep a comparable emergency-care list.

A recent call to the Animal Rescue League brought this "helpful" response: "Well, there used to be an emergency list around here somewhere, but it seems someone took it."

Oh.

The Yellow Pages does not separate emergency care from its columns-upon-columns of regular veterinary listings.

And none of the three most widely recommended emergency-only hospitals lists itself outside its own jurisdiction.

To find the two Maryland emergency clinics in the Maryland Yellow Pages, it's a good idea to know what you're looking for -- before you begin -- because they're not alphabetized under E for Emergency, but under B for Beltway and M for Metro.

But if you don't want to find yourself driving a critically-ill animal to Maryland or Virginia, the best time to shop for a vet who will drop everything and come running when you cry help! -- and there are some -- is before that emergency occurs.