There is almost nothing here from a concerning content standpoint.
The book does introduce the concept of a “diary” to young kiddos, which many parents may want to avoid.
There is a bit of mild negative behavior by the dog (the main character) that would be inappropriate for a child. For example, he has issues with a cat character that leads to rude faces, comments and chasing. Even this comes across pretty lightly. At one point he pretends to pee on a nightstand to get attention. He is rude to this cat throughout most of the book.
Luck is mentioned.
Note: There are quite a few rainbows shown. Fortunately, these are actual (original) rainbows as God intended them and not indicating anything from our secular culture.
