Answer:
5mls
Explanation:
Since the doctors recommend the woman to give her 12 pound mixed breed dog Benadryl 12.5 mg orally, and she has Benadryl liquid that is exactly 12.5 mg per teaspoon, all she has to do is to give her dog one teaspoon only.
Since one US teaspoon equals to 5 metric millimeters.
The woman would need to give her pet 5mls then.