Because heartworms must be eliminated before they reach this adult stage, it is extremely important that heartworm preventives be administered strictly on schedule (monthly for oral and topical products and every 6 months or 12 months for the injectable).
How long is heartworm medication effective?
Heartgard has the active ingredient ivermectin in it. Ivermectin has a half-life of 2 days in the dog. That means 1/2 of the drug is eliminated from the body in 2 days. So at most it is active for 4 days per month.
How long does a heartworm pill last in dogs?
However, due to the heartworm life-cycle, it is likely that giving the medication every 45 to 60 days, rather than every 30 days, will allow immature heartworms to develop into adult heartworms. In other words, heartworm prevention medication is not effective when given every 45 to 60 days.
Does heartworm medicine last more than a month?
Heartworm is a serious but preventable disease. Giving your dog a monthly heartworm preventative year-round (yes, even in the winter!) is one of the most effective ways to prevent heartworm disease. If you miss a dose, be proactive about addressing the problem.
Do dogs need to take heartworm pills every month?
Heartworm preventatives are generally given as a monthly dose and are available in several different types. These include monthly pills that you can hide in his food and topical treatments that you place on his skin that will deter mosquitos.
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