YA Book begins by a girl describing how a dog had crawled up on the porch and died because its staples/stitches had fallen out. She later finds a diary on the beach or in a cave or something of that nature.

[A]

Girl moved to new town with her father.
Understanding is she is a young teen
Read this around 2000-2004
I think maybe her dad was a vet ?

[Rainbowheart]

Maybe something in the Animal Inn series?

The first book is Pets Are for Keeps.