As some of you already know, there's a major outbreak in some parts of HRM of the canine parvovirus. We cannot stress enough how important it is that ALL dogs are immunized against this killer. It is extremely contagious, difficult and expensive to treat, but easy and inexpensive to prevent. Once a dog is infected, even with aggressive, costly treatment, the chances of survival are not good.
Please make sure your dog's immunization is up to date. If you are unsure, please see your vet and ensure your dog is safe before it is too late.
For more info, read this article, it gives a good summary of the virus.