Carlson certainly isn't entirely wrong about suggesting that Candy's dog should be euthanized. The reader can easily imagine how a sick old dog like that could stink up an entire room which is already crowded with men. The poor dog is not to be blamed, but Candy is imposing on all the others by keeping such an animal in a room where they have to put up with its bad smell. Slim doesn't defend Candy or his dog because he sees the justice in Carlson's complaint. In fact, nobody has a word to say in defense of the animal. Candy himself says later, not that he shouldn't have let his dog be shot, but that he should have shot it himself.
That would have been nearly impossible for Candy to do because he has only one hand, and Steinbeck seems to be suggesting that he is right-handed and the missing hand is his right one. He would be trying to handle a German Luger with his left hand. No doubt the pistol has a strong kick because it is a powerful handgun. And how would he hold the gun and the dog with only one hand? Even if he got somebody else to hold his old dog, he would still have a hard time shooting the Luger accurately with his left hand.
Carlson owns the gun and knows how to shoot it and where to point it. There is admittedly a streak of cruelty in this man. He undoubtedly gets some pleasure out of killing the dog--although he doesn't necessarily get any pleasure out of making Candy suffer. He just doesn't understand Candy's feelings at all. Carlson obviously doesn't care much about other people and their feelings. At the very end of the novelette, when Slim takes George off to have a drink, Carlson asks Curley:
"Now what the hell ya suppose is eatin' them two guys?"
Although Carlson believes that George took the gun away from Lennie and shot him in self-defense, Slim probably knows better. He tells George:
"You hadda, George. I swear you hadda."
Slim doesn't mean that George had to defend himself against Lennie but that he had to take the responsibility of becoming his friend's executioner for the good of society and for Lennie's own good. If the reader agrees that it was right for George to kill Lennie, then the reader should agree that it was right for Candy to let Carlson kill his dog. And vice versa.
Steinbeck invented the incident involving Candy's dog for plot purposes.
- It shows that there is a gun available for George to steal when he decides to kill Lennie.
- The gun is a German Luger, which is a very distinctive-looking automatic pistol. When George pulls it out to shoot Lennie it will be obvious that it is Carlson's gun. Steinbeck wrote the book with the intention of turning it into a stage play almost immediately. He is thinking about what the theater audience will see on the stage.
- Carlson explains how to shoot the dog so that it will die instantly and painlessly. George hears the explanation and sees the demonstration, so he knows where to shoot Lennie.
- Carlson spends time cleaning the Luger, giving George the opportunity to see exactly how the mechanism works. Then Carlson puts the gun under his mattress, so George will know where to find it.
- Carlson is an older man. He probably served in World War I and brought the Luger back from Germany. No doubt he keeps it for protection, because life is dangerous for men who sleep outdoors and travel on freight trains during the Great Depression.
- Carlson is disgruntled because he is getting old without any prospects of a better life in the future. He is more bothered by the dog's smell than the other men because the smell reminds him of his life of hard work, bad food, and bleak living conditions. He takes out his bitterness on Candy's dog and on Candy.
- The Luger can be seen as a symbol of Carlson's youth, when he felt strong and confident and that his life had an important purpose because he was going off to war.
- The main plot purpose of the execution of Candy's dog was to show George where the Luger was kept, how it worked, and where to point it at the back of Lennie's head. George had no other way of killing Lennie, and Steinbeck planned to have this happen from the very beginning.
- Once the men assume that it was Lennie who stole Carlson's gun, it provides George with a good alibi. Slim will think George took the gun away from Lennie in a struggle and shot him in self-defense, and all the others, including George himself, will go along with this story. The book and play will not leave any loose ends. Otherwise, if it was thought that George had taken Carlson's Luger at the bunkhouse, Steinbeck might have to explain how he avoided being charged with the premeditated murder of his friend.
- Steinbeck was a conscientious artist. He makes the incident with Candy's dog seem realistic and consistent with the characters of the men involved; but he invented it to serve an important function in the plot.
- A story about the hard lives of itinerant farm laborers could go on for hundreds of pages. Steinbeck wanted to keep his story short so that it would fit into a play running for not more than a couple of hours with an intermission. By having one main character kill the other main character, Steinbeck could shorten his tale to the desired length for adaptation into a stage play. Henrik Ibsen does something similar with his play Hedda Gabler, and such "shotgun endings" are fairly common in literature.
The incident when Candy’s dog is put down does much to illuminate the nature and attitude of many of the men at the ranch.
This incident shows Carlson to be maybe the most forthright and direct of the men, as he is the one who raises the issue of the dog, pointing out that he is old, lame and blind and smells bad. He argues that the dog would be better off dead, offers to shoot him in a humane manner and proceeds to carry out the sad task. He shows, therefore, that he is not afraid to broach unpleasant subjects, and practical minded in his swift execution of his own proposal.
Carlson’s largely hard-headed attitude seems to be shared by most of the other men. At least, no-one, save Candy himself, dissents from Carlson’s proposal. Candy can’t bear the thought of losing his dog, his oldest and best friend, but he cannot prevail against the majority. Therefore we realize from this incident just how alone and isolated Candy feels among the other men. Even although he has been at the ranch for quite a long time, he seems to have formed no real connections with anyone or anything but his dog.
Candy, however, can’t override Slim’s opinion. Slim agrees that the dog should be put down as an act of mercy, and we see here just how much authority Slim wields over the others. When Slim gently but firmly tells Candy that the dog has to be shot, Candy simply gives in and says helplessly: ‘All right – take ‘im’. We see from this that no-one goes against Slim, that he holds an unofficial position of leadership among the ranch workers. He is presented throughout as a man of superior understanding and wisdom and the others seem to instinctively recognize this and consequently they defer to him.
The other men at the ranch, including George, clearly are uncomfortable at the shooting of the dog. We see this from the awkward silence that falls when Carlson takes the dog off to be shot, and when the shot sounds in the distance, all the men look quickly and silently at Candy. They seem to show silent sympathy for him. We see from this that they are not without compassion. It also reveals, though, that they are uncomfortable at showing their feelings. They cannot offer words of comfort to Candy, or do anything to help him.
Carlson is the one you says the dog is an issue in the first place. This shows he is more of an up-front, straight forward character. He knows how to speak his mind and bring up the touchy subject.
Candy on the other hand just agrees with the men. He doesn't attempt to argue with the others, especially Slim. Slim is the one on the ranch who is in charge and everyone knows it. He is respected and wise. Everyone else just shows their sympathy although they can do nothing to help.