[Laurn7f]

Hi all,

I need some advice on flea medicine and dosage concerns.

Mya is 7 years old and has been on Trifexis for years with no problem of side effects, etc. I've been giving her the 5-10lb dose. However, in the last year she's gone from fluctuating between 8 and 10lbs to pretty steadily being between 10 and 11lbs.

The last visit to the vet, they were adamant about her needing the 10-20lb dose and that makes me so nervous. How could an 11lb dog (that is sometimes 10lbs) need the same amount of medicine as a 20lb dog?

I know they say that they can't guarantee protection, and this summer i've noticed more bites on her - no fleas so they must still be dying, maybe just taking longer bc of the dose/weight?

Im not sure what to do because I want her to be protected against heartworm and fleas but I know there are horror stories about this particular medicine and although she's been using it successfully for years, I'm scared to rock the boat by upping the dose. But, is not having her on the accurate dose making her taking it at all pointless if it's not working to the best of its ability?

Any thoughts would be greatly appreciated!!