There are many reasons a dog or cat may urinate more than normal. The medical term for this condition is ‘polyuria’. The most common causes of polyuria include:

# Diabetes mellitus (sugar diabetes)
# Cushing’s Disease (hyperadrenocorticism)
# Pyometra (uterine infection)
# Hyperthyroidism
# Diabetes insipidus (results from an abnormality of the hypothalamus and/or pituitary gland)
# Liver failure
# Kidney failure or infection
# Psychogenic polydipsia (compulsive water drinking)
# Addison’s disease (hypoadrenocorticism)
# Hypercalcemia (high level of calcium in the blood)
# Hypokalemia (low level of potassium in the blood)
# Medications: e.g., Lasix (furosemide), or glucocorticoids such as prednisone
# High-salt diets

Because of the seriousness of some of these conditions, a dog or cat urinating and/or drinking more than normal should be seen be a veterinarian as soon as possible.