Where can i find a holiday cottage for my family and 3 large dogs?

We want to go away to somerset or devon this year and rent a cottage/bungalow etc. my mum has trouble with stairs so a downstairs loo would be nice . we also have 3 beautiful greyhounds so a secure garden is vital. i have sent away for lots of brochures but most seem to offer room for 1 or maybe 2 pets at the most. i would appreciate any help. thanks bernie but white acres dont seem to take pets. nor do the caravans have secure gardens. no disrespect to dorset, i used to live there and its lovely but i want to visit friends in west somerset.
Answer
There are lots of cottages in dorset where i live. many people rent them out aswell.dorset has got great scenary as well as lots of things to do!