5 yr Chi/Rat Dog, female?

Up to date nothing has changed at ALL she has the Run's BADDLY 4th day now, still Drinking Not eating much. Her Pooh is light brown and runny. She isn't under stress she is happy as a lark just not real active because she is tired of using the bathroom. I have a vet, Iv tried the Pepto it's not helped. today she refuses to eat for me at ALL. not even her favorit treat. Were keeping the liquid's down fine she is resting. her eyes are bright, no tempreture on ear's nothing at all to show sighs of anything else. Nose is dry and little. She ate some boiled hamburger last night an a piece of white bread for me . Iv lost my job Im worried of a vet bill. I don't really care in the long run on the bill. Im in deep homes for some understanding. The one thing that changes is we went on vacationf or 4 days and she was baby sat by my older children who did everything properly. her foods never been changed Im at a loss except she is upset we left her and even then it only started once we returned. Any advice would be helpful. Thank you