Hound (see Dog).
Hounds are a kind of dog, usually one that is used for hunting men or animals.
Whereas today in America, many people have a canine as a pet, this was not so much the case in ancient times. Today people kiss their dog on their mouth (dogs lick their rear ends and genitals with that same mouth making that kissing of their dogs a filthy custom), dogs were seen as unclean animals in the Bible. Dogs were mainly used for their character of barking at strangers, so they were more of a natural alarm system. This extensions to attacking intruders.
2 Peter 2:22 But it is happened unto them according to the true proverb, The dog is turned to his own vomit again; and the sow that was washed to her wallowing in the mire.
Luke 16:21 And desiring to be fed with the crumbs which fell from the rich man’s table: moreover the dogs came and licked his sores.
So dogs are accustomed to filthy habits.
Philippians 3:2 Beware of dogs, beware of evil workers, beware of the concision.
You cannot understand this warning by Paul unless you understand true evangelism, taking the gospel out into the street or door to door to explain the gospel to people on a one on one basis. When doing that, you will meet guard dogs that will bark and try to bite you. Paul says to be careful with them. — David Cox