I'm not sure how long it has been since she pee'd last in regards to when she drank the water and then immediately pee'd. That might play a role.
If she's peeing more frequently than you think is normal, it wouldn't hurt to have her checked out at a vet..make sure she doesn't have some issue with her bladder.
To answer your question, Mandie doesn't do what you are describing so I don't think it is a size/small breed thing.
__________________ Terri, proud mom to Mandie  & Shelby-Dale  |