There is a new heartworm medicine for sale in the market already. Small dogs below 11kg only RM30 to Rm40 lah. Can last 6 months since it is 6 tablets and 1 tablet one month. I am not using HeartGuard, I'm using Heartz, a good brand also.

Heart worm medication contains same active medicine inside to prevent heartworms, hookworms, roundworms and something else. Just the brand and where it is made makes it expensive.

6 months is a good age to start heartworm prevention.