Adverse reaction to worming?

Okay my turn to question. Anyone EVER had an ADVERSE reaction
to Worming? Diablo 16 yrs, wormed last night, MAJOR vomiting
and pain in stomach and hiding all night and labored breathing.

Called the vet, but had not heard of such before... anyone else?

He has been wormed with no ill effects before.

He vomited massive amts then drank and hid. He
was it seems fine by this afternoon/morning and
eating again etc.

So, any insights? Anyone else experience this?

what did they use and was he weighed first?

No, the vet gave him 2 pills - yellow - I'm pretty
sure it was a broad spectrum for the roundworm,
hookworm and tapeworm and I was sure it was
Droncet. That's why his reaction suprised me.

She knows his weight - at 15lbs he's heavy.

The other kitty also got wormed, Lexi
(who is MUCH lighter) same dose of 2 pills. She
also had her boosters. Knocked her out
for the rest of the day/night. almost 24 hrs,
but no vomiting, just sore and sleeping it
off sort of reaction.

I'm not sure, but I think in the past I gave 1.5 pills for
Tapeworm and Roundworm/Hookworms.

I haven't heard back from her, but as I'm leaving
tomorrow am, I won't have time to talk till I
get to where I am going. But I will be following up.

I would call the local er clinic and just ask... silly ? why were you worming an animal of this age??

Because he still goes in/out, and is with a young cat
who brings in prey. Which she WON"T eat but he WILL
eat!

Also, no matter how hard I try, they do get fleas
and fleas = tapeworms

have you tried revolution??? Ionly ask since two vets looked at me a bit nuttily when I asked for wormer for my 17 yr old...

Yeah, but of the 2 I prefer worming (or did) to giving
them topical insecticide (which is what frontline is...)