1. An action against an attorney or veterinarian to recover damages for malpractice, whether based on a breach of duty or contract, must be commenced within 4 years after the plaintiff sustains damage or within 2 years after the plaintiff discovers or through the use of reasonable diligence should have discovered the material facts which constitute the cause of action, whichever occurs earlier.
2. This time limitation is tolled for any period during which the attorney or veterinarian conceals any act, error or omission upon which the action is founded and which is known or through the use of reasonable diligence should have been known to the attorney or veterinarian.