A person commits an offence if, without lawful authority or reasonable excuse, he—
administers any poisonous or injurious drug or substance to a protected animal, knowing it to be poisonous or injurious, or
causes any poisonous or injurious drug or substance to be taken by a protected animal, knowing it to be poisonous or injurious.
A person commits an offence if—
he is responsible for an animal,
without lawful authority or reasonable excuse, another person administers a poisonous or injurious drug or substance to the animal or causes the animal to take such a drug or substance, and
he permitted that to happen or, knowing the drug or substance to be poisonous or injurious, he failed to take such steps (whether by way of supervising the other person or otherwise) as were reasonable in all the circumstances to prevent that happening.
In this section, references to a poisonous or injurious drug or substance include a drug or substance which, by virtue of the quantity or manner in which it is administered or taken, has the effect of a poisonous or injurious drug or substance.