I'd like a second opinion. When you face a serious medical problem or pro-cedure, you don't hesitate to say this.

But what do you do when it's your dog with the problem, and you're talking to your veterinarian? If your dog is suffering, you want help as soon as possible. But you also want to be sure that the diagnosis you have is correct, and that you're selecting the best treatment. How can you be sure, and should you be getting a second opinion for him, too?

When it comes to second opinions, there are few rules. Each animal, each veterinarian, each situation is different. And the term "second opinion" includes a wide range of options. Perhaps the only rule is this: As the dog's advocate, you must be comfortable with the diagnosis your veterinarian has made, and the treatment protocol which is recommended.

It's an important responsibility, and sometimes a daunting one. There are some basic guidelines to follow, though, and some basic questions to ask when you face an important healthcare decision for your dog.

First, clarify the situation. Make sure you understand exactly what the veterinarian has told you. She should explain her diagnosis, including how she arrived at it and how certain it is. She should also tell you about other treatment options, and why she recommends this one.

Find out if she's consulted with anyone about your dog. This is the easiest form of second opinion, and it should be part of your veterinarian's normal procedure if there's any uncertainty. She can talk with colleagues at the clinic or on-line, or speak with specialists.

Many laboratories offer consultations with board-certified specialists as part of their service. She can also subscribe to an on-line veterinary network, such as VIN or NOAH, which have board-certified specialists available. Perhaps these consultations will be enough to alleviate your uncertainty.

Clarify the time factor, too. Is this an emergency that requires an immediate decision, or do you have time for consideration? Don't stall, but if it isn't urgent, don't be afraid to take time for your decision.

Next, decide what exactly you're unsure about. Do you question the diagnosis itself, the recommended treatment, or both? Is it an objective or subjective question? If you're concerned that she really hasn't found the right diagnosis, maybe there are more tests to run, or tests to repeat. If the results themselves are accurate, maybe there are other possible interpretations. What are the other possibilities and how have they been ruled out?

A diagnosis of "shattered femur" leaves little room for question. But there is subjectivity in the treatment choice -- should it be plated, pinned, or amputated?

A medical condition may have several accepted treatment protocols, with different drugs and dosages. Is this the best one for your dog?

Euthanasia is a big subjective question. There's often no right answer, but you may want another opinion on the dog's chances of survival or his future quality of life.

Or maybe it's something intangible -- the tone of the vet's voice, a hunch you have, anything. The point is to try to identify it. This is what you really want to have answered.

Ask for a second opinion. Remember the rule: You must be comfortable with the diagnosis and the treatment protocol. If this still isn't the case, tell your vet that you'd like a second opinion. Be up front about it and explain why. "I just want to be sure" is good enough, or you can be specific. Don't worry about hurt feelings -- this is part of the profession, and it doesn't imply that you don't trust your vet. In many cases, your vet will suggest that you do this before you even ask.

Tell her what you want, if you know. Maybe you have another doctor in mind already, or you want to go to a certain facility or see a certain specialist. If not, ask her to recommend someone.

If your vet refers you to another doctor for a second opinion, she'll probably choose an appropriate specialist. Many vets maintain strong relationships with referral clinics or university hospitals, and have already worked with the specialist you need. This is probably the best answer for any serious or complex problem. You can expect a definitive answer based on the most current knowledge and technology.

Your vet will make the initial contact with the other doctor, and describe your case. You may have to make the appointment yourself, but your call will be expected. Your vet will forward the case history and related materials such as X-rays and other test results.

The referral vet will give a complete report of the findings and proposed treatment to your vet. If the treatment itself requires the specialist, that will be noted, too. But you should be returned to your vet for continuing care as soon as possible.

Another option, more extreme, but sometimes appropriate, is to go to another veterinarian on your own. If you choose to do this, the new vet won't have the benefit of the existing work-up. You'll also have the expense of repeated tests and procedures that may not have been faulty in the first place. And the second diagnosis and treatment recommendation are only definitive if they're the same as the first. If not, you have two different opinions from two different professionals, and no real basis for deciding who's right.

But you gain things, as well. Because he starts from scratch, the new vet won't be influenced by old assumptions. He may follow a different diagnostic path, or see things that were missed before, and that may lead to an answer.

You can also form your own educated opinion. With computer technology, you have access to a huge array of resources (see Internet Resources). Many of these can help you get reliable information and advice about your dog. They can help you become a better-informed consumer of pet health care by helping you ask informed questions, and make informed judgments.

Here's a disclaimer, though: No one can do a physical exam by modem. They can't observe your dog, palpate him, or look down his throat. They don't have a doctor-patient relationship, and they can't make a diagnosis. Every reputable veterinarian on the Net will emphasize this, and encourage you to see your vet in person.

But you can still ask for information and advice. "My vet says this. Does that make sense to you?" "Have any of you had your dogs on this treatment? How did it go?" Ask good questions, and you just might get some good answers.

In the end, you must choose. If the second opinion agrees with or refines the first, your decision is easy. If they don't agree, you can make a judgment call, or get a third opinion. You can get all the opinions you want, but at some point you'll have to decide what to do, whom to trust, what makes the most sense to you. If you follow these guidelines, you'll have the information you need to make that decision with confidence.

The Internet has a tremendous variety of pet and veterinary-related resources. You can access lists with just a modem. For web sites, you'll need Internet access. For the forums, you must subscribe to the particular service.

It's best to be familiar with these sources ahead of time. Try them out, decide which you like best, and be ready when you need advice. In the meantime, learn from others and add your own experience to the community. You may even choose your Internet service provider based on their pet forum. Remember, these are just a few examples of what's available.

• http://netvet.wustl.edu/vet.htm

NetVet is a comprehensive site with links to hundreds of online resources -- an excellent place to start. It has an extensive index, including specialty organizations, veterinary home pages, referral hospitals, vet schools, newsgroups, mailing lists, etc.

• http://www.avma.org

The American Veterinary Medical Associations home page is another good starting point.

• http://www.vet.cornell.edu/consultant/consult.asp

A technical site, "a diagnostic support system" for veterinarians, Cornell University's site can be used for background information. You input signs or a diagnosis, and it gives you links to specific online information.

These are e-mail message lists where you converse with other dog owners and veterinarians. They're a good place to get advice and opinions.

Often one of the hundreds or thousands of people who read your question will have experience with it and make suggestions to you.

(See the NetVet site above for a much more complete list of lists.)

Vetmed list:  (send message: "SUBSCRIBE VETMED Firstname Lastname" to listserv@iupui.edu)

CANINE-L list:  (send message: "sub CANINE-L your name" to listserv@psuvm.psu.edu)

Cyberdogs list: (send message: "subscribe cyberdog" to majordomo@iastate.edu)

These are a more interactive version of lists. America Online's Pet Care Forum, and Compuserve's VetCare Forum are excellent, although there are others.

Remember: These sources can help educate you, give you advice, point you in the right direction. But they can't diagnose your dog. Use them to aid your interaction with your personal veterinarian.