The sin that a dog represents is Gluttony.
Gluttony is the act of overeating, over drinking, or overindulging in anything to the point of waste.
Gluttony can also be described as a limitless appetite for food and drink, or a habit of eating to excess
Within the pages of the Bible, the dog emerges as a symbolic embodiment of impurity, sin, and moral waywardness.
Revelation 22:15: “For without [are] dogs, and sorcerers, and whoremongers, and murderers, and idolaters, and whosoever loveth and maketh a lie.”
What the Bible says about dogs is both positive and negative.
In the Bible it says that God cares for animals including dogs and they should be treated with kindness.
The positive things that the bible says about dogs is that dogs are not listed as ritually unclean animals and they are mentioned in passages which indicate that they served as positive roles.
For example in the Bible, Isaiah refers to sheep dogs as guard dogs and Job mentions dogs tending his flocks.
In the Book of Tobit, Tobias's pet dog also accompanies him on a journey.
The negative things the Bible says about dogs is that the term "dog" is sometimes used as a slur or term of reproach, such as in 1 Samuel 23:14, 2 Sam 3:8 and 9:8.
In Revelation 22:15. "dogs" are listed among those that are shut out of the kingdom of heaven.
The Bible also teaches you that animals should be cared for and they can teach life lessons.
Proverbs 12:10 says, "The righteous care for the needs of their animals".