I have a question regarding doing a snap test for a heartworm check in a ferret--if a ferret can harbor only one or two adult worms, what if they happen to be male worms? I understand that a snap test only indicates if an adult female is the culprit; apparently it detects the hormones put out by a female? Was reading an article in a vet magazine tonight regarding detecting heartworms in cats, and the article said that a lot of cats only harbor male worms (for whatever reason), that the snap test is designed for dogs, and even if the cat does have a significant load, the snap test may not pick the presence up. They recommend ultrasound. Would this be the prudent choice for detection in ferrets, rather than using the possibly useless (in ferrets--works great in dogs) snap test? [Posted in FML issue 3232]