how is carlson's loneliness shown when he shoots candy's dog?

You know, I don't really see that in here. Carlson just felt the dog smelled up the bunkhouse.

It's true that all these guys are lonely but I don't see this in Carlson's motivation to shoot Candy's dog.

but dont you think that when carlson says the dog is useless and wouldn't suffer if it was dead, then he was refering to himself as well as the dog? which shows his loneliness

I'm going to look at this in terms of 'looking' in from the outside. Candy and his dog are companions, they have love between them, and Candy feels an emotional bond he otherwise wouldn't because of his dog. Carlson realizes this, and he understands the lonliness of men in their position...... but he also sees an old dog that's past its prime, and sometimes it's the people on the outside who can see a well loved pet's infirmities far better then the actual owner. Thus, this is why Carlson encourages Slim to take one of the new pups. It's not that he didn't understand Candy's need for companionship, but rather that he did. His efforts certainly weren't compassionate, but his actions in all reality probably saved the dog pain and saved Candy from having to do it himself.

Sorry, I just don't read this into Carlson's personality. He might have been lonely but the whole dog thing didn't have anything to do with whatever isolation he might have felt.

so you dont think carlson shot the dog due to his own loneliness and thinking that he feels lonely therefore he is no use to anyone just like the dog?

No I don't. Carlson is a minor character who Steinbeck doesn't spend much time exploring. There is no textual evidence, that I can see, to say the killing of Candy's dog has to do with his own loneliness.

do you think any critical incident that carlson was involved in shows his loneliness?

I am going to chime in here just for the reason that I don't want to "answer" in your other question box. I searched high and low for quotes, descriptions, context clues, and you name it...... looking for anything in this novel that alludes to Carlson's loneliness. I can't find any.......... as Aslan has already stated, Carlson is a minor character. We get a pretty thorough physical description and we can tell a lot about his character from his actions. But lonely? I don't see it.

Actually, if you connect the dots, the killing of Candy's dog does show how Carlson is lonely. George said somewhere that lonely ranchers eventually get mean and unsensitive to others' emotions and by bothering the Candy to get rid of the dog and not understanding how George felt after killing Lennie shows how unsensitive he is. It might sort of be a far strech, but still seems pretty reasonable.