What is the test for a claim against a defendant in a medical malpractice case?

The plaintiff is required to establish that the defendant owed him a duty of care, that the defendant’s behaviour breached the standard of care, that he sustained damage and that the defendant’s breach caused the plaintiff’s harm in fact and law. Mustapha v. Culligan of Canada Ltd., 2008 SCC 27 at para. 3.

In order to succeed, the plaintiff must prove both a breach of the standard of care as well as causation on a balance of probabilities. The plaintiff must prove that but for the defendant’s breach of the standard of care, the injury would not have occurred. It is not sufficient for the court to infer causation or to draw an inference based on common sense; the onus is on the plaintiff to lead evidence to demonstrate that the defendant’s negligent conduct caused the injury. Clements v. Clements, 2012 SCC 32; Fowlow v. Southlake Regional Health Centre, 2014 ONCA 193; Tahir v. Mitoff, 2019 ONSC 7298 at para. 41.

Both parties agree that to establish liability for animals in negligence, special circumstances must exist. The owner of an animal cannot be negligent if the animal acts in an unexpected way and injures someone. There must be foreseeability of harm and unreasonable conduct. Put another way, it must be found that the owner of the particular animal, with its particular characteristics, and in particular circumstances, could have reasonably foreseen the danger that could result in damage. Wilk v. Arbour, 2017 ONCA 21 at para 39-40.