Hello all, I have 10 week old and was wondering if I should buy these medications now or wait until his appointment with the vet and talk to him/her on Sept 4th? I live in So Cal.
The official American Heartworm Society recommendation is to start puppies at 8 weeks of age, based on their weight. Here's their page of FAQs for pet owners:
Advantage Multi is labeled as young as 9 weeks (it covers fleas too), so a week later if you want to use that one. Heartgard and its generics are labeled as young as 6 weeks depending on weight.
All that being said....I've had several sets of rescue pups that came to us around 12 weeks that were started on Advantage Multi as soon as we got them. They didn't get HW disease (and I'm in one of the worst states for it). OTOH, Ad Multi kills juvenile heartworms readily when used monthly, so even if there were some immature worms in the pups I had, it would have taken care of them them (it's the only one that has been shown to kill juvenile worms...it's why we use it!). I have no idea they'd have had the same positive outcome with Heartgard, as I only ever use Ad Multi on rescue dogs.
If you're not starting them until your pup is 12 weeks soon, I would perhaps ask the vet about prescribing Advantage Multi instead of one of the cheaper pills. It ends up being good value because it also gives decent flea protection (like Advantage II combined with HW and deworming). You'll just need to buy a single tube at a time in the beginning when the pup is growing fast, as the pup will need a bigger size at 20 lbs. and again at 55 lbs. (and again if it ever gets over 88 lbs.). Once you're over 55#, then you can *probably* safely buy 6-packs online at Allivet for around $75 per 6 pack (a GOOD price for both flea and HW). You have year-round fleas in So Cal, so the pup will need something for that anyway. Or in 6 months, you can switch to something else, as at that point, it will have killed any immature HWs that might have been in the pup growing already.