Hi, we stayed in a lovely cottage near to Harlech at Llanfair a couple of years ago. The website is
http://www.hengaeau-farm.co.uk
There are 2 bedrooms, one double one twin, nice fitted kitchen with washing machine and dishwasher, bathroom, hallway, and a nice large lounge/diner. The cottage is on a working farm, but if your dog isn`t very active after his/her operation this shouldn`t pose a problem. There is a small paved patio outside the lounge patio doors, and this leads onto a small garden. It isn`t completely enclosed, but unless your dog is fit enough to jump low walls it should be OK. The cottage has it`s own driveway, a dirt track really from the farmyard, but there is a farm gate that you can keep closed. There is ample parking for a couple of cars, lovely views, and only a couple of minutes drive to the nearest beach. Harlech is a mile away, and it`s not too much of a drive into Barmouth. Betwsy-coed is also a very nice day out, nice village with shops and cafes, and beautiful surrounding scenery.
The lady at the farm, Mrs. Thomas, is really nice, you can also buy eggs and milk from her.
Be prepared to have the odd sheep in the garden or on the patio, but they soon run off if they see anyone!
Hope this has been of some help.