-Ivomec 1% - 50ml injectable solution
-0.1ml per 10 lb (30-lb dog would get 0.3ml, 40-lb dog would get 0.4ml, etc.). 1/10th ml for every 10 lb of dog.

My question for Jack is: For the adult worming schedule, (rotational schedule of many different wormers), my Pit Bull Bible shows Ivomec given every other month instead of monthly (as all the other heartworms e.g. Heartguard recommend), which is the correct timeframe?

Thanks in advance