Polydipsia, or increased drinking often occurs with increased urination, or polyuria. Polydipsia and polyuria can be caused by kidney failure, diabetes, uterine infection, liver disease, high blood calcium and metabolic abnormalities caused by disease of the pituitary gland. The vomiting of blood may be related and could be due to a clotting disorder as a result of liver or kidney disease. Other causes include gastric ulceration, drugs, ingestion of foreign bodies. These are very serious signs and you should see a vet as soon as possible.