Since arriving home it has had diarrhea with a bit of blood and won’t eat; with kibble soaked in goat milk it only drinks the milk and leaves the kibble, and ignores canned food too

A dog with bloody diarrhea can be caused by different things, including food issues, gastrointestinal problems, parasites, stress, and infectious disease. A dog just arrived home may develop acute hemorrhagic gastroenteritis from food intolerance or stress; in that case, IV fluid therapy plus anti-inflammatory, hemostatic, and anti-diarrhea medication is generally advised.

If treated with medication alone, the effect may be unclear and could even worsen symptoms. If the dog is not vaccinated, focus on ruling out infectious diseases.