If I had included a spoiler, I would have used that. But it's more like the back of the book blurb. If it happens right at the start of the book and you know it within 5 minutes of reading it, it's not a spoiler.
It's like that movie, Marley and Me.
is a spoiler. Owen Wilson buying the dog in the first place is not (since it's in the title and in the poster).