Commonwealth Court Vacates Verdict, Holding Comparative Negligence Instruction Improper in Dog Attack Case

When the plaintiff, a volunteer at the dog shelter, arrived at the shelter, a dog on a leash jumped up. The plaintiff moved away and told an employee of the shelter to take the dog away. As the plaintiff walked away, the dog attacked her from behind. 

During the trial, the court provided the jury with an instruction on comparative negligence. The jury entered a verdict in favor of the plaintiff, but it also determined that the plaintiff’s comparative negligence was 50%, which reduced the award of damages. 

On appeal, the issue before the Commonwealth Court was whether there was enough evidence of negligence by the plaintiff to submit the question of comparative negligence to the jury. In other words, whether a reasonable person in the plaintiff’s position would foresee that the dog had vicious tendencies and, thus, had to exercise care to avoid the risk of attack. 

The court determined that while the plaintiff may have understood the risk of another jump, she did not understand the risk of a vicious attack. The court explained that “for a duty to arise, the dog’s ‘unmistakable vicious tendencies’ had to be known.” Based on the evidence of the record, the court held that the plaintiff’s brief encounter with the dog did not reveal the animal’s vicious tendencies. According to the court, the defendant failed to present evidence that the plaintiff should have foreseen the risk of an attack. 

The court reasoned that a reasonable person would not expect that a dog on a leash presented a risk of an attack. The court held that “when there is no evidence of the plaintiff’s negligence, no instruction to the jury on contributory or comparative negligence should be given.” As such, the court held that the trial erred in giving the jury instruction on negligence by the plaintiff. 
 

_{Case Law Alerts, 4th Quarter, October 2025 is prepared by Marshall Dennehey to provide information on recent developments of interest to our readers. This publication is not intended to provide legal advice for a specific situation or to create an attorney-client relationship. Copyright © 2025 Marshall Dennehey, all rights reserved. This article may not be reprinted without the express written permission of our firm.}