A police officer may destroy an animal, or cause it to be destroyed, if—
(a) the animal has been seized under section 137 (1) , 146 (2) (c) or (d) or 157 (1) (h) or the animal’s owner has given written consent to the destruction; and
(b) the police officer reasonably believes that the animal is in pain to the extent that it is cruel to keep it alive.