Approx 3hrs after worming with Drontal my dog was sick.  I have no reason to suspect that it was a reaction to Drontal as we've used it since he was a puppy with no ill effects.  It's most likely that he was sick because he'd been chomping a rotten apple in the orchard and some tree bark whilst my OH was chopping wood; also a few too many treats and a bit of dog hair for good measure!!  He is sick from time to time so that's not too unusual.

However, what should I do about the worming tablets?  Can I assume he had ingested them properly or should I redo him?

If its been 3 hours, then you won't need to redo. The rep told us that if the dog vomits within the hour then repeat the treatment, otherwise should be fine.

Thank you

tess was sick the last time i used drontal. so this time i gave her half a tablet a day and wormed her over 4 days and had no problems, my sisters dog was the same too.

All my dogs have been violently sick with Drontal Flavour but they were fine with the normal Drontal. I've changed mine to Milbemax now with no problems

My youngest one can't seem to stomach Drontal either.  I've now switched to a daily natural wormer and so far so good.