I just want to expose the lie that dog owners have been fed. We had a Dog that got Heart worm in Ohio when everyone thought Northern dogs could not get heart worm. We had a dog who got heart worm in NC & a great vet saved him. This vet was super smart & had found out that a Cattle wormer named IVERMECTIN worked & at this time we were giving our dogs arsenic based concoction that was poison. Today they have pills that are similar to but not as effective as Ivermectin liquid Cattle wormer. When you read the instructions in Ivermectin it will say not to give it to Dogs. This is Pure BS. But collies do have a sensitivity to Ivermecetin, that is the only breed. This lie about not giving it to dogs was brought to us by the same Liars that waited until the stocks of Arsenic heart worm poison ran out of stock. The way you give it is use 10th of a cc per 10 pounds of dogs weight. Small shot needles can be obtained from your vet or MD. Diabetics use these for insulin they are One CC syringes divided into tenths. If your dog weighs 50 pounds you use 5 tenths of One CC. My current Vet is onboard with what I use but She feels that many people are not competent enough to do this. The current form of Heart guard has problems & dogs can still get heart worm. This is due to the chemical change done to protect 1 breed, the Collie. If you believe you can tell a Collie from a German Shepard & tell a 10th of a CC from one CC then try this out. We have been using Ivermectin for 30 years with zero Heart Worm infection in any of our many dogs. Ivermectin is given once a Month even through the Winter months! IVERMECTION is the safest most effective treatment for preventing Heart Worm Infection period. You can buy Liquid IVERMECTIN at any farm supply store. The Product MFG. is Merial & the Name is Ivomec injection for Cattle & Swine. It comes in a 50 ML bottle. You will need to withdraw the IVERMECTIN with the one CC Syringe with a needle. Then you transfer it to a one CC syringe with needle removed. You can squirt the liquid into there mouth by holding their lower lip out & squirting it in the pocket. This stuff taste BAD & they will spit it out if you just squirt it anywhere in their mouth. We feed our Dogs a Raw food diet so we just squirt it right on their food right from the bottle no need to transfer it to a Needless Syringe. I am telling you this because I hate people in Big Pharma who lie for profit! We have saved thousands of Dollars over the years compared to the super Expensive Heart Worm Pill you get from Vets & pet supply. If you are serious & want to use this for you loving pet & have any serious questions PM me. And last but most Important: Get your Dog checked for Heart Worm infection first by a Vet! ATTN: I m editing the Above post. The dosing I have given is incorrect. Thank You @texasnurse for providing this up to date information on the proper safe dosing of IVERMECTIN in Dogs. Please read the information in the following post.