Heartworms in dogs???

I have a 45lb lab mix. She tested positive with a light case of heartworms. Are meds w/ ivermectin just a preventative or can we put her on them now and let them kill the parasites???She was tested at the pound when they picked her up for getting out of our yard... we didnt talk to the vet on site but someone at the shelter told us to put her on ivermectin.

If she tested positive, you must have had the test done by a vet, right? The vet will be the one to prescribe the correct course of treatment.

You have to be careful what you give a dog positive for heartworm. Some medications will cause all the worm load to die at once. It can be fatal. A 40$ vet apt will answer all your questions AND get your dog the proper medicine.GOOD LUCK.