The leader of the Flushed Pets is named Snowball. The Flushed Pets hate humans because of past mistreatment. In George Orwell's Animal Farm, Snowball is one of the two pigs who lead the revolution on the farm against humans who have mistreated animals.
When Max and Duke are escaping from the animal gang, a turtle starts bouncing around ahead of them knocking animals out of the way with the video game sound effect of the turtle-like Koopa Troopas that kill enemies in the Super Mario Brothers video games.
Max is a Jack Russell terrier, Duke is a Newfoundland or Sheepdog mix, Gidget is a white Pomeranian, Mel is a Pug, Buddy is a dachshund, Chloe is a house cat, Sweet Pea is a budgerigar, Norman is a guinea pig, Pops is a basset hound, Tiberius is a red-tailed hawk, and Ozone is a hairless Sphinx cat.
Among the horde of cats attacking Max in the alley, there are several references to famous cartoon cats: among those, there is an orange, fat cat with a close resemblance to Garfield (2004), the Siamese Si and Am from Lady and the Tramp (1955) and the black, white faced Francis from Felidae (1994).
In the telenovela 'The Passions of Passion' the male character Fernando is voiced by Jaime Camil, who also plays Rogelio, a telenovela star best known for his role in 'The Passions of Santos' in Jane the Virgin (2014).
Universal corporate synergy is high in this film. Billboards for NBC Universal properties The Tonight Show Starring Jimmy Fallon (2014) and Saturday Night Live (1975) can be seen on buildings outside the apartment building. A poster for Universal's Sing (2016) can be seen on the back of a metro bus. Another sign has the "YouTube" logo and says "Most Viewed Video Of The Day".
If you look at Tattoos' tattoos you can see a unicorn, a nod to Despicable Me (2010) and another that says Made in France where the animation was done. There is also the triforce design from the Zelda games above the butterfly.
Snowball the rabbit states that in his past life he was owned by a magician. His character looks suspiciously similar to the rabbit Alec Azam from the Pixar short film Presto (2008) which is about a magician's rabbit.
There are several references to humans worrying about their cell phones more than their pets - Katie forgets her phone near the beginning of the film, the dog walker is consumed with his phone in the park, etc.
The bus in the climax is numbered P15 and the next stop is First Ave. and 89th St. Station. Neither the bus nor stop would normally exist. During the construction of the Second Ave. subway, the bus line M15's 86th St. stop was moved to 89th St., and Second Ave. is the opposing one-way street to First Ave.
Although credited as an additional voice, experienced voice actor Jim Cummings once lent his voice to Steele, the evil dog from Balto (1995), another talking dog movie distributed by Universal Pictures.
In the part-way closing credit scene, Buddy and Mel attend what they think is a costume party at Leonard's house. Buddy dresses up as a Barbaloot from Dr. Seuss' The Lorax (2012), while Mel is dressed up as a Minion from the Despicable Me (2010) franchise.
There is an indirect reference to Disney's movie Bolt (2008) when Duke and Max face the cats in the alley. Duke moves the same way Bolt does and refers to "Thunder and Lightning" which are the symbols of Bolt. Bolt is also capable of escaping such situations which Max and Duke cannot.