If the RSPCA were called to check out the house depicted in the advert and found a large healthy hound, with a secure garden to roam in, a kennel that was big enough for the dog to stand, turn round and lay down flat in. Also the dog is not tied to the kennel and there are people in the house to let him in if he wanted in. They would not be interested.
The majority of complaints are because the dog is shown in a kennel and some people think it's OK to hurl abuse at people that keep dogs in kennels.
If you want to nit-pick you could say the kennel had fairy lights on it and so must have p