Why Is My Cat Drinking a Lot of Water?

A cat that is suddenly drinking noticeably more water than usual (polydipsia) almost always has an underlying medical condition. Unlike dogs, cats evolved as desert animals with a low thirst drive — they naturally drink very little if fed wet food. Increased thirst is therefore a more significant signal in cats than in most other species.

## What Counts as "Too Much"?

Normal water intake for an adult cat on a dry food diet: approximately 40–60 ml per kg of body weight per day. On wet food, cats drink much less from a bowl because wet food contains 70–80% water. A sudden increase in bowl drinking — especially in a cat previously on wet food — is abnormal.

## Most Common Causes

Diabetes Mellitus
One of the top causes in middle-aged to older cats, particularly neutered males and overweight cats. The classic triad: excessive thirst (polydipsia), frequent large-volume urination (polyuria), and weight loss despite a good or increased appetite. Blood and urine tests confirm the diagnosis.

Hyperthyroidism
The most common endocrine disease in older cats (10+ years). An overactive thyroid elevates metabolism, causing weight loss, increased appetite, hyperactivity, and increased water intake. A neck palpation by your vet can often detect a thyroid nodule.

Chronic Kidney Disease (CKD)
The kidneys lose their ability to concentrate urine, so more water is needed to flush waste. CKD is extremely common in cats over 7 years and progresses slowly. Early detection through blood tests allows significant life extension with diet and management.

Liver Disease
Toxin accumulation from liver dysfunction causes nausea and increased thirst alongside jaundice (yellow tinge to skin/gums) and lethargy.

Pyometra (Unspayed Females)
Uterine infection in unspayed females causes profound thirst, lethargy, and abdominal distension. An emergency if the cervix is closed (no discharge visible).

## What to Do

Do not restrict water — your cat needs it. Book a vet appointment and request blood and urine panels. Bring a urine sample if possible (collect with non-absorbent litter pellets).

Log daily water consumption with Flovvi so you can show your vet the trend and onset date.