{ "@context": "https://schema.org", "@type": "BlogPosting", "headline": "Cat drinking a lot and losing weight – kidneys, diabetes, or thyroid?", "description": "Is your cat drinking a lot and losing weight? Find out when kidney disease, diabetes, or hyperthyroidism could be the underlying cause. ", "datePublished": "May 08, 2026", }

Cat drinking a lot and losing weight – kidneys, diabetes, or thyroid?

Cat drinks a lot and loses weight – kidneys, diabetes, or thyroid?

📞 Appointments and advice: 010 739 9130

📍 Sacrum Animal Hospital, Porttisuontie 13, 01200 Vantaa

Quick answer: If a cat starts drinking significantly more than before and loses weight, there may be an underlying internal disease. The symptom should be investigated with blood tests, a urine sample, and a veterinarian's assessment.

Increased drinking and weight loss in cats are common reasons to seek examination. The change can happen slowly, in which case it is only noticed when the litter box becomes wetter than before.

When to see a vet?

Contact a veterinarian if any of the following apply:

  • The cat drinks or urinates more than before.
  • The cat loses weight, even though it eats well.
  • The cat vomits repeatedly or is lethargic.
  • The coat deteriorates or the cat withdraws.

What could be causing the symptom?

1. Kidney failure

Especially in older cats, kidney disease can increase drinking and cause weight loss.

2. Diabetes

Diabetes can cause intense thirst, frequent urination, and weight loss.

3. Hyperthyroidism

The cat may eat well but lose weight and be restless.

What can you do at home?

  • Monitor drinking and the litter box's urine amount.
  • Weigh your cat regularly.
  • Book an examination, if you notice these changes.

What happens at the vet?

The examination often includes blood tests, a urine sample, and a general check-up. A treatment plan is then created based on the results.

Sacrum Animal Hospital can help

If you are unsure about the severity of a symptom, it's better to contact us than to wait too long to monitor the situation. A professional can help assess whether it's an emergency or if an appointment can be scheduled.

📞 Appointments and advice: 010 739 9130

📍 Sacrum Animal Hospital, Porttisuontie 13, 01200 Vantaa

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