Disney Answer: No
Unfortunately (or fortunately), the three Disneyland Resort Hotels, the Disneyland Hotel, Grand Californian Hotel and Spa and Disney’s Paradise Pier, are NOT pet friendly. They do not allow pets of any kinds in the rooms, other than trained service animals. If you are planning on bringing a service animal with you to stay at one of the three Disneyland Hotels, you must notify Disney in advance.
Service Animals are also allowed in the parks, but are not allowed in certain areas and on certain rides.
Disneyland also operates the Disneyland Kennel Club, located to the right hand side of the main entrance to Disneyland. The current cost is $20 per day per animal, but overnight boarding is not allowed. Kennels are available for your pets on a first-come, first-served basis. Reservations are not accepted.