I was using Sentinel with no problems,they dont make it for over 100lbs. Vet said I could double up on it.
Same stuff I used "now" IIRC it's Rx (by prescription) only...
there was another one I used prior, don't remember the name exactly
I think I got it from Tractor Supply (?) or maybe the vets inhouse store (?)
when they made you have a Rx for any of it here, Heartguard (? maybe)
pill form, no shots
I've never done the shots, not for any of my animals
I never had any real issues with heartworms either, dogs are mostly indoors
unless out to pee or poo or training playing, twilight hrs are supposed be the worst
dawn & sunset
Mine were a chewable pill, monthly prevention maybe the deterrent (?)
But the rescue/foster dog I had Bubba had heartworms,
when I first started fostering him
I had to bring him in, they did a week or more worth of inhouse vet treatments,
mega doses of some shots I believe too
'allegedly killed them off'
the rescue org. FOAC.us paid for, I know it was expensive too...
No idea what they used, or I don't remember when they told me...
that was 9 years ago
Bubba, pointer lab mix