The whole premise, while innocent fun to kids, is an absolute nightmare for adult pet owners
- Duke telling Max that he can't go back to the shelter, as it'll be the end for him. It is nightmarish especially when you realize that some pet shelters can be designated 'kill shelters'. If he'd gone to a kill shelter, he'd most likely have been euthanized, because most such facilities only keep unclaimed pets for 72 hours.
- The feral cats. They are skinny with mangled whiskers and freakishly large eyes.
- Tiberius luring Gidget into his cage by promising to help her find Max. She doesn't even realize he's trying to make a meal out of her (even when walking though the pile of bones littering the cage floor) until she takes his hood off and he tries to attack her.
- Snowball’s sociopathy and mood swings. He even goes into graphic detail about murder at one point...
- The Viper, along with the other snakes in Snowball’s lair.
- Max being almost bitten by the Viper. Apparently the other feral animals, and (possibly) Snowball survived, but Max may not have been so lucky...
- Pops’ paralysis. Take into account that he is very old and in a doggy wheelchair, and puts himself into highly dangerous situations to rescue Max and Duke. Chloe is understandably apprehensive by this.
- The fact that Duke can never go back to his first owner since he was elderly and had died before the events of the film. The cat who now lives at the old house breaking the bad news to Duke is downright heartbreaking.
- The climax where the Animal Control van with Duke inside ends up crashing through the guard rail and dangling precariously off the scaffoldings is pretty intense. Max tries to rescue Duke as the van drops even further through the support bars. Just as Max manages to retrieve the keys, the van plummets into the river below as the other animals watch in horror. Then the keys float out of Max's grasp. As the sinking van fills up with more water, Max and Duke desperately try to bust the cage door open to no avail. If it weren't for Snowball, Max and Duke would've died.
- Technically, Max could have survived by swimming out of the van, but he wasn't going to leave Duke, who was stuck in his cage.
