As the weather starts to warm up a cat’s water requirements naturally increase. However, cats are very adept at masking signs of illness and often it is only very subtle changes in their behaviour (eg. increased drinking) that are early indicators of serious diseases. This can make it quite difficult to tell whether your cat is drinking more due to the time of year, or an indication of an underlying problem (eg. diabetes).
A cat should drink on average 60mls/kg per day of water. That means a 4kg cat should be drinking approximately 240mls a day (about one cup) to ensure their body functions properly.
However, when determining the volume of drinking water required under normal circumstances, we need to take into consideration your cat's diet. Wet or canned food contains about 80% water where as dry food contains about 10%. A 4kg cat solely eating canned food may only need to drink about 30ml of water per day where as the same cat eating only dry food would need to drink more than 200ml of water per day.
If you are unsure, your veterinary health care team would be happy to provide advice on how much your cat should be drinking, taking into consideration their diet.
It is often difficult to measure accurately exactly how much your cat has been drinking, especially if there are multiple cats or other animals in the household. Other signs that can indicate an underlying disease process include the following.
If you suspect your cat's water intake has increased or are unsure, a thorough check over by your veterinarian is highly recommended as the sooner a disease is identified, the better the prognosis. Your vet will most likely also recommend some pathology tests requiring a blood and/ or urine sample to help determine the cause of the polydipsia (increased drinking).
A general blood profile can provide information on kidney and liver enzymes, glucose levels and also assess the health of the red and white blood cells. Further blood tests can be run, when indicated, to assess thyroid hormone levels.
A great deal of information can also be obtained from a urine sample from your cat - including the presence of glucose, blood, protein and the concentration of the urine sample. You may be requested to collect a sample from home – not an easy task but achievable if your cat uses a litter tray.
The four most common problems diagnosed in association with an increase in water intake are:
All of these diseases are serious, but early detection and treatment improve the outcome dramatically.
Cats are very fussy about things in general and water is no exception. Male cats especially benefit from drinking sufficient water to help prevent urinary tract disease. Older cats are less inclined to drink water and are subsequently more likely to become dehydrated. They are also likely to have underlying diseases processes requiring a greater fluid intake. Accordingly, you should encourage your cat to drink sufficient water all year round to help prevent disease (and especially in summer).
A thirsty cat could be an unwell cat, so it is vitally important that you contact your veterinary health care team to discuss any concerns that you have.