My pet)

I have a ferret. His name is Ad. It is very funny, but sometimes I am afraid of him. Every day I take a walk with Ad, play with him and feed him, every week I wash it him with shampoo, although Ad doesn't like it.

My pet)

I have a ferret. His name is Ad. He is very funny, but sometimes I am afraid of him. Every day I take a walk with Ad, play with him and feed him, and every week I wash him with shampoo, although Ad doesn't like it.

[Good work.  You can refer to the ferret as 'him', 'her' or 'it'.  Once you referred to your ferret as 'him', then you should use 'him' for the rest of the text.  My friends that have ferrets (not many of them) say that they are fun, but very mischievous.]