If a main character in a novel is a veterinarian who helps other people's animals all day long and harms his dog at home, you could say the writer was employing Symbolism
Foreshadowing
Analogy
Conflict
Irony

Irony  

Explanation:

There are several meanings of irony, some of which are the following:

the use of words to express the opposite of what we actually mean. For example, if it's raining outside, we can say: It's such nice weather today!when the outcome of a situation is the opposite of what we would expect. This is called situational irony. A veterinarian helping other people's animals while harming his own dog would be an example of situational irony.