For optimal performance, the chewable must be given once a month on or about the same day of the month. If treatment is delayed, whether by a few days or many, immediate treatment with HEARTGARD and resumption of the recommended dosing regimen minimizes the opportunity for the development of adult heartworms.
How many days late can you give Heartgard?
The common consensus is that it takes about 40‒50 days for heartworm larvae to mature to the point where heartworm preventatives no longer work. So, from the initial mosquito bite to the beginning of maturation, there is an approximate 45-day grace period that a heartworm preventative can provide protection.
Can I give my dog heartworm medication late?
Most of the monthly heartworm medicines have a safety factor of at least 15 days of protection if a dose is missed. This means that if you're just a week or two late, your pet is likely still within that window of protection and would be unlikely to become infected during that time.
What happens if I forget to give my dog his heartworm pill?
A dog who has missed just two monthly doses of preventative or is late for a heartworm injection can become infected with heartworms.
What happens if you miss 2 months of heartworm medicine?
I have missed 2 months of heartworm prevention for my dog. What should I do? You need to consult your veterinarian, and immediately re-start your dog on monthly preventive—then retest your dog 6 months later.
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