We're considering changing his treatment from Mitaban dips to using Ivermectin, which I really wanted to avoid.
October will be 6 months from his first heartworm test. Any 'teenager' heartworms that he had at that time wouldn't be picked up by the snap test, so you wait 6 months and test them again. It gives the teens time to mature into adults and to show up on the heartworm snap test (assuming they're female - heartworm tests only pick up the hormones produced by female worms).
The other reason why I wanted to avoid it is that we don't know what breeds Tad's mixed with. The herding breeds (Collie, most importantly) are very sensitive to Ivermectin. It could be fatal to use Ivermectin in collies. To counter this because there are so many mixes out there, you start off with a low dose and work up to a normal dose. This way, if a reaction is to occur, you've most likely NOT given a fatal dose. It could cause Tad to seizure if he has any collie/herding breed in him, but it should not have any 'permanent' damage if he has a reaction. Obviously, Tad's most prominent breed is not 'collie', but we're not sure what else he has in him. Just my luck...it's collie.
On one hand, you have a drug that reacts with his skin and causes intense itching and extreme lethargy, and on the other, you have a drug that could potentially kill him. :/ But, the one that could potentially kill him is a whole heck of a lot easier, more convenient, and (if he's collie free) pretty harmless, assuming he is, in fact, heartworm negative.
