Plaintiff Must Present Evidence of Owner Negligence When Cow Causes Accident on Interstate

February 12, 2024 | Jennifer Harrington

On February 2nd, 2024, the Iowa Supreme Court affirmed both the Court of Appeals and district court's finding that the injured plaintiff failed to bring forth evidence that the owner of a cow that caused an accident on Interstate 80 was negligent. The court made clear that an animal on the road is no longer prima facie evidence of owner’s negligence. A livestock owner owes a “duty of reasonable care.” Breach of that duty can be established using the res ipsa loquitur doctrine, but the plaintiff needs to present evidence that “in the ordinary course of things” the injury would not have occurred if reasonable care had been used. 


On January 26, 2019, a cow standing on I-80 was hit by a semi-truck. The cow died, the truck was damaged, and the driver injured. The cow came from fenced property bordering the interstate and owned by the defendant.

In August 2019, the driver plaintiff brought suit against the defendant cattle owner on a single count of negligence. The petition claimed the defendant was negligent because he allowed his cow “to travel into the highway.” Due to a series of delays, the trial was scheduled for August 2022. In June 2022, the owner moved for summary judgment arguing the driver had no evidence that he was negligent.

The district court granted the summary judgment motion and dismissed the case. The driver appealed, and the court of appeals affirmed the dismissal. The driver appealed again, arguing both lower courts errored when they required the plaintiff to prove additional evidence of negligence. The plaintiff argued that proving the cow was on the road was enough to show the owner was negligent. 


Iowa tort law requires that a plaintiff alleging negligence prove that the defendant owed a duty of care, and the defendant breached that duty.  A presumption of negligence does not arise because an accident or injury occurs.

Cattle Owner’s Duty of Care

The only duty a livestock owner has arise from common-law. Under this standard, a livestock owner has a “duty of ordinary care,” which is the care that an “ordinarily prudent and careful farmer exercises under like circumstances[.]” When the livestock owner has land that borders a road, they should “use reasonable care to avoid creating hazards” in the roadway.

Further, in Iowa there is no longer a statutory duty to fence cattle in. The court explained the repeal meant that an animal on the road is no longer prima facie evidence of owner’s negligence.

Evidence of breach

Once the standard of care is established, the injured plaintiff must produce evidence that the defendant owner breached the standard of care. They can provide direct or circumstantial evidence of breach. In this instance, there was no direct evidence of breach. The plaintiff did not provide any evidence of holes in the fence or unsecured gates.

The plaintiff argued there was circumstantial evidence of a breach using the res ipsa loquitur doctrine. The res ipsa loquitur doctrine requires the plaintiff prove two elements: (1) the injury was caused by something under the “exclusive control and management” of the defendant and (2) the injury would not have happened “in the ordinary course of things” if reasonable care had been used. The court assumed without deciding the first element could be proved by the plaintiff, but found that the plaintiff could not prove the second element.

The court found that the plaintiff was assuming “’in the ordinary course of things,’ cows cannot escape an adequate fence after an owner has properly closed the gate.” The court reasoned that could not be assumed as true without expert testimony. The court “ [doesn’t] think the nuances of bovine behavior are so widely understood that a jury of ordinary citizen would be able to say that . . . a cow would not have escaped without negligence.” Since the plaintiff did not bring forth an expert on escaping cow behavior or any other evidence that cows only escape if reasonable care is not used, the court ruled that the plaintiff could not establish that the owner breached the duty of care.

The court finished with a final note that made clear that an expert is not necessary for all negligence cases that involve animal escapes. Instead, each case must be analyzed separately to determine what evidence res ipsa loquitor principles require to be presented to the factfinder.