​​​​​Any animal which is injured is not seized under the Companion Animals Act but under the Prevention of Cruelty to Animals Act 1979 (POCTA).

If a person seizes or takes charge of an animal in any circumstance where it has been injured, it is the responsibility of that person to ensure that the animal receives the attention required.

If you're the driver of a vehicle which hits a cat or dog, you're responsible for ensuring that the animal receives appropriate treatment to alleviate pain. This is stated under the Prevention of Cruelty to Animals Act. The driver of the vehicle involved must also inform the owner of the animal, or an officer of the RSPCA, Animal Welfare League or a police officer as soon as it is practical to do so.