How long can it be given to a dog?

Please provide me with more context! I need to know what "it" refers to before I can answer your question.

For example, are you asking about:

* A specific medication? Please provide the name of the medication.

* A specific food? Please tell me what kind of food it is.

* A specific treat? Please tell me what kind of treat it is.

* A specific toy? Please describe the toy.

Once I have more information, I can provide you with a helpful response.