When Bruce first checks in Henry near the beginning of the movie, he writes Henry's name in green (at around 4 minutes) following Friday's name inscribed in a heart. Later when Bernie is reading from the check-in book, Henry's name is in red (at around 27 minutes) and follows Cooper.
At the party, a drink is spilled only down the front of Andi's dress (at around 01:02:00). When she returns to the hotel, the stain is all over the back and the front of her dress (at around 01:06:00).
After taking dogs from an Animal Control truck, Mark, Andi, Bruce, Dave and Heather are shown (at around 48:41) in the alley by the hotel walking abreast toward the camera with dogs in their arms and on leashes. There are 8 cuts (9 shots) from 48:41 to 48:52 with many changes the specific dog(s) each kid controls and with Mark switching from the left side of the screen to the right and then back.
When Friday smells the man eating the hot dog, the hot dog does not have ketchup on it. But, when Friday is watching the man eat the hot dog, the hot dog has ketchup.
In a close-up, Bruce puts kibbles on a floor switch panel (around 43:02) to entice Romeo to step onto it, but when the camera cuts to a longer shot of Romeo, there are no kibbles on the panel.
The school bathroom at the beginning of the movie where Bruce is sealing the rock in the box is the same bathroom used later on in the hotel.
(at around 1 minute) Heather is trying to coax the three legged dog onto the ramp, she then praises him saying "good boy". Then at the end (at around 1h 22 minutes) Bernie calls her "Chelsea".