The "dangerous propensity"

The dangerous propensity that is required in a dog bite case is the tendency of the dog to bite a person without provocation. It does not matter whether the intention of the dog is to guide or herd, as in a collie, or to kill, as in a fighting dog. The intention of the dog is legally immaterial. What matters is that the dog has the tendency to bite, because dog bites are intolerable. Furthermore, it is not necessary to prove that the dog previously bit a person, because the gist of the tort is keeping a dog that indicated it wanted to bite humans. 

The common law developed the concept of dangerous propensity to determine legal liability in all cases where a domestic animal caused injury. The traditional formulation, set forth in Restatement (Second) of Torts, § 509 (above), refers simply to "a domestic animal" and not specifically a dog. To analyze a dog bite case, therefore, one must focus on the actions of the dog that are legally sufficient to enable the jury to conclude that the dog owner either knew or reasonably should have known that his dog would someday bite a person.

It has generally been held that the prior behavior of the dog in a bite case must consist of proof of a vicious temperament. Such proof can consist of one or more actions of the dog, such as a bite, a snap, growling, lunging, or chasing people or animals. If the proof is limited to an act that was not a bite or attempt to bite, however, the parties must determine whether the courts having jurisdiction of the case did not previously rule that such behavior was insufficient proof as a matter of law. For example, it is often held that merely chasing animals does not establish proof of a dangerous propensity to attack humans. 

Here are some of the characteristics of a dog that were held to support a finding of dangerous propensity:

• The dog bites people without provocation. Buffington v. Nicholson (1947) 78 Cal.App.2d 37, 43.
• The dog previously bit a person who had provoked it. Reynolds v. Reichwein (1973) 510 P.2d 895, 1973 Colo. App. Lexis 857.
• The dog follows the victim for 50 feet, barking at the victim, prior to the attack. Gomes v. Byrne (1959) 51 Cal.2d 418.
• The dog growls, barks and lunges at people. Bulow v. Dawn Patrol (1963) 216 Cal.App.2d 721, 728-729.
• The dog was trained to fight other dogs
• The dog is an Akita. Wright ex rel. Wright v. Calvin Reid Const. Co,. Inc., 723 So.2d 55 (Ala. Civ. App. 1997).
• The dog runs loose on common areas, barks at a stick and lunges at a stick in a vicious manner. Gibbs v. Grenadier Realty Corp. (1991, 1st Dept) 569 NYS2d 76, 173 AD2d 171.
• The dog is a pit bull and it barks and lunges at children. Giaculli v. Bright (1991 Fla. App. D5) 584 So.2d 187, 16 FLW D 2164.
• The dog is a guard dog. Bulow v. Dawn Patrol (1963) 216 Cal.App.2d 721, 728-729.
• See also the cases holding that the defendant had notice of the dog's dangerous propensity, in the section pertaining to notice under this topic.

The following facts were deemed insufficient to prove the dangerous propensity to bite a person:

• Chasing cars and motorcycles. Chandler v. Vaccaro (1959) 167 Cal.App.2d 786.
• Chasing people but not biting them. Starling v. Davis (1970) 121 Ga.App. 428.
• The dog is a Rottweiler, but exhibits no other dangerous behavior. Moura v. Randall (1998) 119 Md.App. 632, 705 A.2d 334.
• The dog is 100 pounds, is a German shepherd, and its name is "Thunder." Lundy v. California Realty (1985) 170 Cal.App.3d 813
• The dog might attack a person who threatened the dog with a stick. Buffington v. Nicholson (1947) 78 Cal.App.2d 37.
• The dog is a female who was nursing pups when it bit a person who came near the pups. Chandler v. Vaccaro (1959) 167 Cal.App.2d 786, 790.
• The dog is a puppy that suddenly woke up and nipped a person's hand, causing a minor break in the skin. Tessiero v. Conrad (1992, 3rd Dept) 588 NYS2d 200, 186 AD2d 330.
• The dog engages in so-called "muzzle greeting." Provorse v. Curtis 732 NYS2d 310 (App. Div. 4th Dept 2001).
• The dog is kept tied to a post. Dunnings v. Castro (1994, Tex. App. Houston (1st Dist)) 881 SW2d 559.