what different ways can you get intelligence levels for your pet. i saw on subetalodge that their are only 700 something books, and i saw a pet with an intelligence of over 1000. im just wondering how else you get intelligence points

There are quite some items that can raise intelligence. You can see the stat booster list here.

There are some items out there, such as Shinwas Key or stat-increasing tomes, that can help raise your pet's intelligence without having to read them a book. However, these stat-increasing items are usually at higher prices than most books.