I have to say its not a myth. It's even talked about in my small animal medicine class taught by a professor dvm. But believe as you will. Horses are a larger animal so take them for example. The difference between a gelding and stallion is quite noticeable. But I will agree and say that most dog owners should spueter their dogs because owning an intact dog is a big responsibility. I work quite closely with my humane society so I see it every day. But thats not saying it is healthy. I never once said they shouldn't spay. But that it isn't a end all because she had ONE heat. I believe I also said for them to be extremely watchful. I'm not talking about over population. I'm talking health.
I believe I already told her about a spay during heat. The simple fact was that she is already in heat so its pointless to sit there and criticize the problem. I choose to do what I want with my dogs and was offering insight that there are a few benefits to one heat that is handled responsibly. I see this Outlook on life is not looked upon positively here so ill keep these discussions to my forums where they are.