Changes in appetite or drinking in dogs and cats can be early indicator of systemic diseases. Increased drinking in particular is often dismissed by owners as a sign of normal ageing but it may often be abnormal and be caused by disease such as renal or liver failure, diabetes, thyroid or adrenal glands disorders, or infection (pyometra). The outcome of these conditions is more favourable if detected early so increased drinking is an important sign of the need for investigation.
Normal water intakes are estimated to be between 20 and 70ml per kg per day: a 20kg dog will generally drink 3/4 to 1L every day. Amounts above 100ml/kg/day will be considered definitely increased. However every individual is different, and normal water intake can vary a lot. Some pets may still be considered to have significant increased drinking below 100ml/kg/day, and it is important to pay attention to differences to their usual behaviour.
Consulting a veterinarian is recommended to investigate the cause of the problem, and additional diagnostics tests such as blood tests, urinalysis or diagnostic imaging are commonly required.
