According to the dictionary

According to the dictionary, ethics is defined as the study of what is morally right and wrong ( The term animal ethics is also believed to be what is right and wrong based on beliefs, values, and morals of animals. The ethical dilemmas arise when two opposing points of view address the issue of rights, equality, and how animals should be treated.

The two philosophers with two different opposing points of view are Peter Singer and Tom Regan. The utilitarian approach is Singer and with Kantian approach is Regan. Both philosophers are similar but, slightly different. Singer and Regan are similar in the fight for animal rights. The difference with the two philosophers is that Singer view is on animal equality and Tom Regan view is on both humans and animals rights.