Does the doctrine of assumption of risk apply to a dog owner who deliberately or negligently conceals a known hazard from a veterinarian?

Similarly, the court of appeal in Nelson v. Hall, supra, 165 Cal.App.3d 709, 211 Cal.Rptr. 668, held that the doctrine "does not mean dog owners could never be held liable for injuries to veterinarians or their assistants. We emphasize that the defense of assumption of the risk extends only to the danger which the injured person has knowingly assumed; i.e., the danger the dog will bite while being treated. [p] Moreover, if a dog owner purposefully or negligently conceals a particular known hazard from a veterinarian, he or she would not be relieved of liability, for this would expose the injured person to an unknown risk. (See Lipson v. Superior Court, supra, 31 Cal.3d at p. 371, 182 Cal.Rptr. 629, 644 P.2d 822.) This question is not before us, since defendants are not accused of negligence or knowledge of any particular vicious propensity on [the dog's] part." (Nelson v. Hall, supra, 165 Cal.App.3d 709, 715, fn. 4, 211 Cal.Rptr. 668, emphasis in original.)