What are the most common factors showing a dog owner knew or should have known their animal may be vicious?

The most common factors demonstrating that a dog owner knew or should have known their animal may be vicious include, but are not limited to:

• Frequently confined animal –may indicate a dangerous animal.
• Dog is kept outside —keeping a poorly behaved dog outside allows the dog to practice that bad behavior.
• Owner warning strangers about animal —may indicate animal might cause harm to others.
• Dog kept on a chain —chained dogs can become more aggressive. Keeping a chained dog is illegal in most places.
• Muzzling —may indicate a dangerous dog.
• Warning signs on property —may indicate owner knows dog is dangerous.
• Size of animal —the larger the animal, the greater the chance of causing injuries.
• Animal breed —such as pit bulls, Rottweilers, German shepherds.
• Aggressive behavior —frequent snapping and biting shows owner knowledge.
• Owner received complaints about dog —but did nothing or not enough.
• Animal fights with other animals —may demonstrate vicious nature.