Why is my manky Dog immune to flea and worm meds

[VivaLeBeaver]

Have had mutt two months. Drontol and front line regularly. Always had fleas so last week got advocate from vet.

He still has fleas and this morning there was a fairly long worm in his poo. Think it was a round worm.
What can I use next?

Hi, have you treated the house and any other animals in the house too? There is no known resistance in fleas to frontline or advocate so either you didn't apply correctly or, more likely, he's picking up new fleas from somewhere (unfortunately most likely the carpets/rugs/sofa etc)

Also ask for milbemax from your vet for worming

Thanks, will get some of that. I did wonder just if the worms were dead due to last week's advocate. They didn't seem to be wriggling but I didn't look for long!