All the Pretty Little Collies - A Foxglove Corners Mystery, #27

Spring turns deadly for Jennet Ferguson when a demented individual targets the collies of Foxglove Corners with tainted meat and ominous threats. When Jennet Ferguson discovers poisoned meat on Sue Appleton's horse ranch, she vows to find the person responsible for this outrage. Before long, a young collie owner presents her with another problem. She has been receiving anonymous messages advising her to withdraw her dog from future shows or risk the consequences.
In the meantime, Jennet's friend, Annica, claims to have seen a ghost picking flowers in the wildflower field planted by her and Brent Fowler.  She worries that the sighting may have ominous significance for her.