There are 2-3 different methods, I believe. Slow kill, then the two ways for the quick kill method.
For quick kill you can:
Do 2 shots, 24 hours apart then a month later oral Ivermectin - I believe. Hopefully another rescue person will see this and confirm.
Or the recommended is for 3 shots. One shot, then four weeks later, 2 shots 24 hours apart. Then the Ivermectin.
These (Immiticide) shots kill the adult worms - large worms living in your dogs - 6 inches or more in length. So you can imagine when these worms in the dog die, that they might clump and form a clot, which is made worse by movement. Which is why leash potties only, no exercise, and bed rest or leash tethering are so important for 4weeks after each shot (or shots) and another month at least after the Ivermectin. See the Houstin Shelties rescue link in the other thread.
Check with your vet on all but better safe and conservative in my mind, than sorry.
The Ivermectin kills off any baby worms at the end.
Staging can involve urinalysis, bloodwork, and 2 xrays and the HW test. In my mind light positive is less important than what they see in the xray but I am not sure on that. You can go to the rescue section, follow up, and see my foster's xrays posted in stunning bi/black in Lawrenceville GA thread.
Hope this helps. Will look for a link I like and post it here. Please read that Houston Sheltie rescue thread. Aftercare is huge. My vet has scared the
out of me with stories when I had one other foster undergoing HW tx and again, better safe than sorry!
http://www.marvistavet.com/html/body...treatment.html
http://www.marvistavet.com/html/heartworm.html