Does my dog still have worms?

My 100lb American Bulldog had tapeworms coming out in his stool for a couple weeks, i called the vet and asked if i could pick it up on a certain day she said it'll be fine, and after that they just disappeared. Around the same time I was about to pick up dewormer (just incase) he went into anaphylactic shock due to an unknown allergic reaction. After rushing to the vet at 1am, he had uncontrollable diarrhea, to the point it was water and would come out if he moved a certain way. I've been holding back on giving him a dewormer, cause his stomach was a little sensitive for a while. But I looked through every stool hes made since I saw the worms and they aren't there, are they gone? Or just in hiding?Forgot to mention he's on Trifexis since beginning of January after my neighbors flea infested cats came into our yard, that's actually when my vet saw the tapeworms and I thought the was lying (but didn't tell her) & she still didn't give him anything after his check up, she just prescribed trifexis and said he'd be fine after a bottle of pettime? Hence why I didn't get rid of them when she told me.We treat our property every so often for fleas with pet/human safe whatever its called, being that there are 3 other dogs other than my ABD (all separated) and the cats can only get to my ABD cause he don't care for cats, but the pitbulls in the back can't stand them so they know his area is a safe zone, after they return from who knows where since they're roam around cats and not indoor cats and breed like cockroaches. We live in hawaii so its easy for cats to go to one place to another and come back infested.