Worming and flea treatment help please

[Bagofworries]

I'm very new to all things dog and am totally confused about worming and defleaing treatments.
I have a 4 month old puppy who is approximately 8 kgs in weight.
I have him on a pet plan with the vets which covers worming and flea treatment, and so far, I've been given so much different advice that I'm getting very confused.
When I phoned the vet and they explained the pet plan to me, they said because of his age, I would need to give him 1 worming tablet and the flea treatment per month. I took him for a check up with the vet nurse and to get him weighed and while there, I signed him up to the pet plan, and at this point, I was told he needed worming every 2 weeks and defleaing once a month.
I just phoned to arrange to pick up another worming tablet and have now been told he is only meant to be given half a worming tablet every 2 weeks and 4 weekly flea treatment until he is 6 months old, when it all changes again.

Does anyone know if worming is monthly, 4 weekly or 2 weekly? Is it half a tablet every 2 weeks or a whole tablet every 2 weeks or month?
What about the flea treatment?
My brain is all foggy now.
Is it advisable to be breaking worming tablets in half?
The vet are giving me Drontal Plus for worming and the dropper on the back of the neck for defleaing is Advocate.

Is it the bone shaped ones? Have you read the leaflet. Googling it says this:
Dosage Guide:

Puppies and small dogs
½–2 kg bodyweight = ¼ Drontal Plus Flavour Tablet
2–5 kg bodyweight = ½ Drontal Plus Flavour Tablet
6–10 kg bodyweight = 1 Drontal Plus Flavour Tablet

Puppies should be treated at 2 weeks of age and every 2 weeks until 12 weeks of age. Thereafter they should be treated at 3 month intervals.

And flea treatment is normally every 4 weeks

Although Dogs trust says:

Puppies should be wormed from two-three weeks of age at two weekly intervals until they are twelve weeks of age, then every month until they are six months of age. Worming should continue at least three times a year with a recommended veterinary preparation for the rest of the dog’s life.

Dementedpixie, Thank you for your quick reply. Yes, it is the bone shaped wormer. My puppy is more than 8kgs now.
I didnt take him home until he was 12 weeks old, but he was on a different wormer up to 12 weeks old.
Will this matter now? Do they have to build it up in their systems?
Do I need to start from scratch now?

I would maybe give 1 tablet a month for the next 2 months and then after the one at 6 months move to every 3 months.

Thank you demented pixie.
I'll give one worming tablet once a month until he is 6 months old, that sounds simple enough
Thank you for your advice. Much appreciated.

Worming treatments only kill worms if the dog has worms that day. It does not prevent worms for the next 3 months.

Bananarama, that's interesting! I wasnt aware of that. How can I prevent worms in my dog? Is there any way?

You can't really prevent them ever getting worms given all the stuff they eat. That's why lots of people worm them frequently rather than waiting to see symptoms.

Some people prefer to pay for worm counts regularly and only treating if positive. You would need to collect samples of your dogs poo and send it off to laboratories.