I'm often faced with clients transferring to our clinic from other vets, and this can be quite a challenge, especially if they're seeking a second opinion. There is the very human temptation to say that the other person is wrong and promote your own opinion. But I am very strongly of the opinion that this is the wrong thing to do for numerous reasons.
Intentionally or not, clients often misrepresent what another vet says. Maybe they misunderstood, maybe the vet didn't communicate well enough, or maybe the client just didn't personally like that vet and wants to bad-mouth them. I've seen clients take a statement such as "I believe..." or "In my opinion..." and translate that as the gospel truth. So as much as it may be hard for clients to understand, many veterinarians take a client's statements with a healthy grain of salt, realizing that it may not be exactly what a previous vet had intended. I've heard clients who took my statements completely wrong, ending up telling another vet something completely different than what I had said and recommended.
I also think that even if I believe that a vet is completely wrong and off the mark, there needs to be a degree of professional courtesy. Criticizing another doctor is a sure way to breed bad feelings among colleagues, and can often come around to bite you back. If I was not directly involved with a case or otherwise have first-hand knowledge of it I'll generally decline to comment about the actions of another vet. There may be details I'm not aware of that would change my opinion, and it's not a good idea to go off half-cocked to later regret it.
If I'm placed in a situation where a client is coming to me for another opinion and I agree with the previous vet, I make a point to tell the client this and support my colleague. If I disagree with the other vet, I'm careful to talk about things only from my viewpoint and use statements like "Based on my training...", "In my opinion...", "According to lectures and articles that I've seen..." and so on. By focusing on my own education and opinions I hopefully avoid being antagonistic towards another vet.
Why do I bring this up? In recent discussions in the comments of this blog other vets and I have had disagreements. This actually happens commonly, even among specialists. Ideally we should all be professional and mature enough to realize that as valid as we believe our opinions to be, they are not the only viewpoint out there. Science actually thrives on differences, as by disagreeing with convention we explore possibilities that may not be otherwise considered. Even in established professions (most vets aren't performing research) new therapies can come from discussions of contrary opinions. The key is to keep it civil. I believe that it is okay to say "I disagree" and provide your reasons. But I don't think it's acceptable to deride someone for having a different point of view.
Thankfully, I have to say that my colleagues who comment on this blog have been such professionals.