In an action to recover damages for personal injuries sustained as a result of dog bites, the plaintiff appeals from a judgment of the Supreme Court, Nassau County (Roberto, J.), entered April 23, 1990, which, upon a jury verdict, is in favor of the defendants and against her.
Ordered that the judgment is affirmed, without costs or disbursements.
This action arose out of an incident on or about June 11, 1984, when the plaintiff received multiple bite wounds from the defendants’ German shepherd. A jury trial was conducted and the jury specifically found that the defendants’ dog did not have vicious propensities.
On appeal, the plaintiff contends that she was denied a fair trial based on the trial court’s refusal to conduct a unified trial on liability and damages. Generally, questions of liability and damages in a personal injuries action represent distinct and severable issues which should be tried and determined separately (see, DeGregorio v Lutheran Med. Ctr., 142 AD2d 543; Addesso v Belting Assocs., 128 AD2d 489). However, separate trials should not be held where the nature, extent, and gravity of the injuries has an important bearing on the question of liability insofar as it is relevant to the jury’s assessment of the dog’s propensities (see, Lynch v Nacewicz, 126 AD2d 708). While cognizant of our holding in Lynch v *574Nacewicz (supra) we find that based on the specific circumstances in this case, any error by the trial court was harmless. Here, the plaintiff was given the option to have a unified trial before the trial began; however, it was not until after a jury was selected, opening statements were made, and testimony was elicited, that the plaintiff chose to withdraw the original application and request a unified trial. Moreover, the court permitted the plaintiff to introduce photographs in order to show the nature, extent, and gravity of the injuries sustained by her. Thus, any prejudice to her was nullified by the admission of the photographs.
The opinion of the defendants’ expert that the defendants’ dog was not vicious was based upon facts personally known to him as a result of his evaluation of the dog, and, thus, his testimony was both relevant and admissible (see, Hambsch v New York City Tr. Auth., 63 NY2d 723; Espinosa v A & S Welding & Boiler Repair, 120 AD2d 435).
Contrary to the contentions of our dissenting colleagues, the facts with respect to what occurred during the encounter were in dispute. The defendants produced sufficient evidence to permit the jury to conclude that the dog was not vicious, and, therefore, we defer to the jury’s assessment of the witnesses’ credibility and decline to grant a new trial (see, Theodosiou v CLD Transp. Co., 147 AD2d 692; DeVaul v Carvigo Inc., 138 AD2d 669).
The plaintiff’s remaining contentions regarding the court’s jury charge are either unpreserved for appellate review or meritless. Thompson, J. P., Bracken and Lawrence, JJ., concur.