Amores perros

Octavio (Gael García Bernal) is in love with his brother's wife Susana (Vanessa Bauche) and dislikes the way she is abused by his brother Ramiro (Marco Pérez). Octavio tries to persuade her to run away with him. Local thug Jarocho, happy after winning in a dog fight, lets his dog loose on some strays and is threatened by a vagrant wielding a machete. Eventually, Jarocho sics his dog on Octavio's rottweiler, Cofi, but his own dog is killed instead. Octavio and his friend Jorge, realising Cofi's potential, become involved in the dogfighting scene. Octavio makes enough money to flee with Susana, and pays Mauricio, the owner of the dogfighting venue, to get Ramiro beaten up. Afraid, Ramiro steals the money and leaves with Susana. Struggling financially, Octavio accepts a challenge by Jarocho to participate in a private dogfight, with no outside bets. Cofi is about to win, but Jarocho shoots him. The infuriated Octavio stabs Jarocho in the stomach. Pursued by Jarocho's thugs, Octavio finds himself in a car chase with Jorge and the wounded Cofi. A collision follows; Jorge dies and Octavio is badly injured.

Magazine publisher Daniel (Álvaro Guerrero) leaves his family to live with his lover Valeria (Goya Toledo), a Spanish supermodel. On the day they move in together, Valeria's leg is severely broken in Octavio's car crash and she is unable to continue working as a model. As Valeria is recuperating in Daniel's apartment, her dog Richie disappears under a broken floorboard and becomes trapped. The missing dog triggers tension and arguments for the couple, leading to doubts about their relationship on both sides. Trying to rescue the dog, Valeria again injures her leg; Daniel finds her hours later. Valeria's new leg injury results in severe arterial thrombosis and eventually gangrene. Her leg is amputated. While she is in the hospital, Daniel finally rescues Richie from the floorboards. When she returns, Valeria drives her wheelchair through the torn-up lovenest and looks out of the window expecting to see a billboard bearing her likeness, only to find it has been removed.

The vagrant occasionally seen in Octavio's story is revealed to be a professional hitman called El Chivo (Emilio Echevarría). He is a former private school teacher who was imprisoned after committing terrorist acts for guerrilla movements. He is trying to make contact with his daughter, Maru, whom he abandoned when he began his guerrilla involvement and who believes that he is dead. He is about to perform a hit on a businessman when Octavio's car crash interrupts him. During the chaos at the car crash, he steals Octavio's money and takes the wounded Cofi to his warehouse hideout to nurse the dog back to health. One day, while El Chivo is out, Cofi kills the other mongrel dogs El Chivo is caring for. He is about to kill Cofi, but decides against it. Meanwhile, Octavio's brother Ramiro is shot and killed during an attempted bank robbery.

At Ramiro's funeral, Octavio meets Susana, and again attempts to convince her to run away with him, but she angrily rejects the notion. A few days later, Octavio is shown waiting at the bus station for Susana. She never shows up, and Octavio does not board the bus. El Chivo learns that his client and his intended victim are half-brothers. He leaves both men alive and chained to separate walls with a pistol within reach between them, their fate left uncertain. He then breaks into his daughter Maru's house and leaves her a large bundle of money along with a message on her answering machine explaining what happened to him. When he is about to tell Maru that he loves her, the answering machine stops recording. He then goes to an autoshop, where he sells the client's SUV. The mechanic asks him the dog's name, and El Chivo calls him "Negro" ("Black"). After El Chivo receives the money for the car, he and Negro walk away, disappearing into the horizon.

Each of the three tales is a reflection on the cruelty of humans towards both animals and other humans, showing how humans may live dark or even hideous lives. But the film's theme is loyalty, as symbolized by the dog, "man's best friend". Dogs are important to the main characters in each of the three stories, and in each story various forms of human loyalty or disloyalty are shown: disloyalty to a brother by trying to seduce the brother's wife, disloyalty to a wife by keeping a mistress with subsequent disloyalty to the mistress when she is injured and loses her beauty, loss of loyalty to youthful idealism and rediscovered loyalty to a daughter as a hit-man falls from and then attempts to regain grace.

Dogfighting is banned in all Latin American countries but exists as an element of the underground economy. Although violent, dogfighting provides an opportunity for Octavio to make money. This is true to life in the sense that participating in the underground economy gives people in the lower class the ability to make money and experience mobility. González Iñárritu was heavily criticized for his inclusion of dogfighting in the film but has claimed that although it is horrible, dogfighting is one of the harsh realities of Mexico City.[11]

The three overlapping stories all take place in Mexico City, but because of class division, there is severe segregation of economic classes with El Chivo squatting on the outskirts of town, Octavio living in a working-class neighborhood, and Valeria living in a luxurious high-rise apartment.[12] If not for the car crash, these three characters would never interact. The upper class is victimized in Amores perros even when they are the ones perpetuating crime. For instance, El Chivo is hired to kill a man's business partner and eventually decides to leave both men to fight it out themselves. Although Ramiro works at a grocery store, he also participates in the underground economy by committing robberies. Octavio and El Chivo participate in the underground economy as well, in order to secure untaxed income and bring stability to their lives.[13]

Amores perros contains domestic violence, gun violence, and animal cruelty.[14] The domestic violence is evident in the relationship between Ramiro and his wife, Susana, when Ramiro beats his younger brother Octavio with a metal rod while Octavio takes a shower, as well as in Valeria and Daniel's relationship as they both begin to become verbally and physically aggressive after Valeria becomes depressed. Gun violence is seen from the beginning of the film in a frantic car chase until the very end when El Chivo hands the gun to the two business partners, leaving them to fight their own battle. Lastly, animal cruelty is quite visible in the dog fights Octavio attends in order to make money off of his dog, Cofi. The dog owners show no empathy toward their dogs.