These are three different ways of describing the same group of false teachers. Paul is using strong expressions to show how he feel about these Jewish teachers who claim to be Christians.
The word "dogs" was used by the Jews to refer to those who were not Jews. They were considered unclean. Paul speaks of the false teachers as though they were dogs, to insult them. If you have a different animal in your culture that is considered unclean or whose name is used as an insult, you could use this animal instead.
"those who mutilate the body". This exaggeration plays on the idea of circumcision. Paul speaks of those who wanted to trim off the foreskin as if they were totally mutilating the body.
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