In at least one of the scenes, the German Shepherd is clearly a male. Then towards the end, the dog is shown nursing a litter of puppies.
Donald M. Flanders (Gary Burghoff) gets trapped in his cabin and at one point he takes the phone into the bedroom, and then the security dog jump at the door and the phone is back on the dresser where it was at the beginning.
When Donald Flander's grabs the phone away from the dog and runs back into the bathroom with it, another phone is shown on the desk.
The two times the dog jumps at the bathroom door, you can clearly see his man parts.
But then "she" gives birth and the litter attaches itself to the mother for milk.
When Toby is calling for the plumber, she says that she is in room 206 on the Prominade Deck, (PR206), but the three girls are shown to be in PR204.
In the final scene, when Stubby and PJ are saying their goodbyes to the crew, the shadow of the boom mic can be seen bobbing around on the bulkhead behind the players, off of Stubby's right shoulder.