labcrab
Posted : 3/5/2007 4:33:49 PM
ORIGINAL: mudpuppy
realize the heartworm tabs act by killing any parasites the pup picked up during the preceding 30 days-- they don't get into the bloodstream and stay there and act as a preventative.
Not sure if you're responding to me and my 45 day schedule - just in case you are (and for lurkers) here's the deal:
The way that Interceptor (and Heartgard) work: when they are given to the dog, they kill all the microfilarae of heartworm that MIGHT be in the bloodstream, and they will kill that microfilarae up to a certain size. The size that heartworm microfilarae reach after 45 days is still killed by Interceptor or Heartgard. That is why it is safe to give the heartworm meds every 45 days (or every 6 weeks). Some vets think that it might even be effective every 60 days, but there is no agreement on that yet. Sticking with a 45 day dosing schedule is fine as is dosing during "high risk" months only. I define a high risk month as one in which the temperature has stayed above 57F for longer than 2 weeks. So, generally speaking I do not dose HW meds during the winter months here in NY.