If you are so opposed to Heartguard and its dosage try one of the many other good products on the market that are more weight appropriate like Interceptor or Advantage Multi or Trifexis for your dogs. You should talk with your "progressive" veterinarian about parasite resistance and what causes it in particular I would question him or her about the MP1 strain of heartworms and why this strain is now found all across the country. There are many reasons not to dose your pet with a product intended for cattle but not many good reasons for not using a labeled FDA approved drug besides price. I have treated dogs for heartworms that have been on ivermectin recipes and I've seen more than 10 different dosages and protocols. Please use approved products it may save your pets lives, but may not save you a few dollars.