What's a generic name for an attack animal?

I'm looking for the name of an animal trained to attack, whether for defense or sport. I feel like it's on the 'tip of my tongue' but can't quite get it.

“Blood sport” is a bit too broad (and, in a sense, too narrow as well), and refers of course to the act and not the creature.

How about fighting? Fighting bull, fighting dog, fighting cock (yes, gamecock might be more common, but I'm trying to make a point here). I don't see a reason why other animals trained to fight cannot be called the same, be them hamsters or narwhals.

A dog trained to attack is called an attack dog. A dog trained for sentry duty is called a guard dog. A dog trained for fighting is called a fighting dog. I can't think of a single word that encompasses all of these types of training.

Sentry or guard animal are two possibilities in the defense category:

Section 1-14 – Dogs or other Animals Used for Sentry or Guard Duty

Any person owning, maintaining, or harboring a dog or other animal for sentry or guard purposes must register said dog or other animal with the Animal Control Director.

A sign warning that there is a guard or sentry animal on the premises must be displayed such that persons are made aware of the presence of a guard or sentry animal before they enter the property. Such sign shall specify what type of animal the guard or sentry animal is.

from the Franklin County, NC, Animal Control Ordinance