Is your cat drinking more than normal? Have you noticed your cat suddenly drinking from the tap? If so, the cause could be a significant underlying disease….
In this post Laura Du Pre, Veterinary Surgeon and Clinical Director of leading Yorkshire based vets Calder Vets, looks at how to identify if there is a drinking problem, what it could be, and how to treat any potential issues.
What is a normal amount for a cat to drink?
Textbooks define normal water intake as 1-2ml per kilogram of bodyweight per hour (equivalent to approximately 25-50ml/kg/24hrs). There is, of course, some variation between individuals, dependent on the amount of water taken in with their food (wet vs dry food), and water lost through exercise and panting.
Polydipsia (increased drinking) is defined as more than 100ml per kg per day. Some cats may have noticeably increased drinking, whilst still drinking less than this amount. More than 50ml/kg/24hrs may raise suspicion about polydipsia, whereas over 100ml/kg/24hrs is definitely polydipsia. Polyuria refers to an abnormally high urine production.
Why might my cat be drinking more?
Water balance is tightly controlled by the body through regulation of water intake and water loss in the urine. Lack of water intake or excessive water loss causes the pituitary gland in the brain to release “anti-diuretic hormone” (ADH). ADH signals the kidneys to conserve water and to concentrate the urine. In these circumstances, the thirst centre in the brain is also triggered to stimulate drinking.
Increased drinking can occur either because the concentrating mechanisms of the kidneys fail, the kidneys do not respond to ADH, ADH is not produced or released, or because there is an excessive stimulus to drinking (primary polydipsia).
The most common causes of increased thirst are:
Kidney (renal) dysfunction Liver (hepatic) disease Diabetes mellitus (“sugar diabetes”) Diabetes insipidous (“water diabetes”) Hyperthyroidism (over active thyroid) in cats Pyometra, an infection of the uterus (“womb”) in unspayed animals Cushing’s disease, an overproduction of natural steroid, cortisol, by the adrenal glands Addison’s disease, reduced steroid production by the adrenal glands Urinary tract infections High calcium