I have a Rat Terrier about 20lbs, I have been giving her Sentinel monthly,She is 10 months old, every time I give her her pill for about two days she seems lathargic and not right, she bounces back though, I don't know if this can cause long term damage, is this a normal reaction for this medication??
I have never heard of this side effect but I do recommend that you change the monthly heartworm if your pet has a reation to it. You can try Revolution. Good luck, vetcare