505.001 DEFINITIONS.
   As used in this chapter unless otherwise specifically provided herein:
   (a)   (1)   “Dangerous dog” means a dog that, without provocation, and subject to subsection (a)(2) hereof has done any of the following:
         A.   Caused injury, other than killing or serious injury, to any person;
         B.   Killed another dog;
         C.   Been the subject of a third or subsequent violation of Section 505.01 (c).
      (2)   “Dangerous dog” does not include a police dog that has caused injury, other than killing or serious injury, to any person or has killed another dog while the police dog is being used to assist one or more law enforcement officers in the performance of their official duties.
   (b)   “Menacing fashion” means that a dog would cause any person being chased or approached to reasonably believe that the dog will cause physical injury to that person.
   (c)   (1)   Subject to subsection (c)(2) hereof, “nuisance dog” means a dog that without provocation and while off the premises of its owner, keeper or harborer has chased or approached a person in either a menacing fashion or an apparent attitude of attack or has attempted to bite or otherwise endanger any person.
      (2)   “Nuisance dog” does not include a police dog that while being used to assist one or more law enforcement officers in the performance of official duties has chased or approached a person in either a menacing fashion or an apparent attitude of attack or has attempted to bite or otherwise endanger any person.
   (d)   “Police dog” means a dog that has been trained, and may be used, to assist one or more law enforcement officers in the performance of their official duties.
   (e)   “Serious injury” means any of the following:
      (1)   Any physical harm that carries a substantial risk of death;
      (2)   Any physical harm that involves a permanent incapacity, whether partial or total, or a temporary, substantial incapacity;
      (3)   Any physical harm that involves a permanent disfigurement or a temporary, serious disfigurement;
      (4)   Any physical harm that involves acute pain of a duration that results in substantial suffering or any degree of prolonged or intractable pain.
   (f)   (1)   “Vicious dog” means a dog that, without provocation and subject to subsection (f)(2) hereof has killed or caused serious injury to any person.
      (2)   “Vicious dog” does not include either of the following:
         A.   A police dog that has killed or caused serious injury to any person while the police dog is being used to assist one or more law enforcement officers in the performance of their official duties;
         B.   A dog that has killed or caused serious injury to any person while a person was committing or attempting to commit a trespass or other criminal offense on the property of the owner, keeper or harborer of the dog.
   (g)   “Without provocation” means that a dog was not teased, tormented or abused by a person, or that the dog was not coming to the aid or the defense of a person who was not engaged in illegal or criminal activity and who was not using the dog as a means of carrying out such activity. 
(ORC 955.11)