As the capital's felines get ready to hibernate inside for the approaching winter, owners have been reminded that signs of excessive thirst may indicate a cat has diabetes or kidney or liver disease.

Canberra Cat Vet doctor John Yang said a general behaviour change was the first thing to look out for as a disease indicator, but unusually high drinking rates and vomiting were next.

"There is three key reasons for drinking more: compensating for something, because there's a metabolic problem, or a psychological problem," he said.

"We would definitely recommend getting those cats into the vet, as the sooner we can see them the greater likelihood of a positive outcome."

Pet Insurance Australia spokeswoman Nadia Crighton said urinating was, naturally, a connected problem for pets downing too much water each day.

"Most cats and dogs with diabetes go to the vet initially because the owner has noticed the animal is urinating excessively," she said. "They are also drinking more, eating more and are losing weight."

Unusual drinking patterns, such as a cat suddenly drinking from a shower, bath or fish pond, should also be watched for.

Dr Yang said most diseases increased urinating. A cat should be drinking an average 60 millilitres per kilogram per day, he said, equating to one cup a day for a common 4-kilogram cat.

Owners will usually be able to pick when their cat is behaving abnormally, but hiding was one example, Dr Yang said.

The good news was cats could generally be helped to live longer lives if the problems which cause excessive drinking among other symptoms were identified early.

"For kidney disease, that's progressive and we're slowing it down, with diabetes, most cats have type-2 diabetes, so they have a chance of remission, but most cats would need lifelong therapy," he said.

Common symptoms of serious medical conditions among cats

• Excessive drinking
• Refusal to eat or drink
• Increase in appetite
• A change in sleeping patterns
• Behavioural problems
• Inappropriate urination or defecation
• Howling when urinating