What Are Signs of Kidney Failure in Dogs?

According to PetMD, common signs of kidney failure in dogs include depression, lethargy, lack of appetite, vomiting, diarrhea, constipation and weight loss. Other symptoms include increased thirst, increased volume of urination, increased frequency of urination, blood in the urine, blindness, seizures and comas. The onset of these symptoms may occur gradually, and not all dogs experience all of these symptoms. Indicators of failure are found in urine and blood tests.