Nearly all of the Haven and British holidays sites are very dog friendly.

hi we always go to http://www.northanfarm.co.uk great site dogs are free as a good dog walk and you are right across road from the beach where your dog can have a good run our kingcharles toby loves it there

hi this is the right web site to thee post above http://www.northamfarm.co.uk

I always take my staffy when camping and usually stay at

http://www.snowdonia-wales.net/acc/camp/cwmlanerch/default.asp

Dogs must be on a lead as with any campsite and if you go into town you can let them loose having a wander up the river. The campsite is clean, usually quiet (unless you get a massive group coming together which only happened once in over 15 times) the showers are not metered (i.e. you dont have to stick 20p in every minute), washing area with hot & cold water and lovely surroundings. Dont pitch next to the little stream though coz of midges lol! Top of the hill is the best spot.
There is a site in the centre of the town but he's miserable and its nearer the river so midges really get on your nerves!

Ive also stayed at http://www.barmouthholidays.co.uk/trawsdir.cfm

If you have a dog, best to stay in the bottom field nearest the main road as there's more space for the dog to run and fab views of the bay in the morning and sunset
They have metered showers though and not as clean a feel as the betws-y-coed site but its not bad.

Are you camping or Caravanning ??

If so check out either the Caravan club website -- their sites take non members in places (Blackpool does) and almost all are dog friendly

there is also the Caravan and Camping CLub but I can't vouch for them as we are not members

Caravan Clubs sites are basic (no bar or proper shop) but very clean