i worm all my dogs every 3 months i use drontal plusxl but they dont seem to work as well as they used to does anyone no if a dog can become immune to them

I'm not sure. But, my youngest husky was actually allergic to them and riddled with worms from when I got him back in February. He was just under 2 years old at that point. He had been wormed on Drontal since he was a pup and no one's quite sure why he had this allergic reaction from when I got him. Every three months he now has to go down the vets and have a worming jab called Droncit. That works very well. Perhaps you should ask your vet about this?

i have asked my vet they say that they are fine but they are always rubbing there bottoms is there any other reasons for this( my male has problems with anal glands but both bitches are fine)

Perhaps they have itchy rear ends! I'm not sure what that could be. I wouldn't say it is definitely worms because they're itching their behinds. Is this constantly or after they've been wormed?!

it is all the time the vet said it was worms even when we are out walking they lay down to lick themselves

So the vet said it was worms but he hasn't offered any sort of medication for it? If that's the case then I'd seriously consider changing vets and definitely getting the Droncit injection, or if you prefer, a few people on here recommend Panacur worming tablets.

Your vet seems to be pretty sure it's worms so I would trust his word for the time being. After all, I'm not a vet but the only thing I can recommend is change to a different brand of wormer and see what that does.

thanks for the advise i will try that

No problem. If you need any more advice, feel free to PM me

Just jumping on the band wagon of this thread.

I gave Poppy a Drontal Plus tablet this morning at about 9.30am in with some scrambled egg, she's had a good size lunch at 1.45pm and a biscuit about 30 minutes ago, but she hasn't done a poo yet.  Last time I wormed her, she'd done about 5 poos in the space of about 3 hours!  I'm getting a bit worried (paranoid probably) now.  How long does it take for the wormer to get through?  I'm worried that she might poo and I miss it (worried in case she eats the worms - if there are any). 

I have no idea how long it takes to get through. I think it's about 24 hours. There shouldn't be anything to worry about if you keep her wormed regularly and keep watch on what she's doing. I wouldn't worry too much but keep an eye out for her poo tomorrow!