Do Steroids Cause Excessive Thirst in Cats?

'Could you please fill my water bowl again? Oh, the food bowl, too, if you don't mind.'
i George Doyle & Ciaran Griffin/Stockbyte/Getty Images

If your vet prescribes steroids for Fluffy's illness or physical problem, prepare to keep that water bowl full and to hear the sound of constant lapping. A common side effect of steroid use is excessive thirst, but you know what else results. Get ready for litter box floods.

Common Steroids

The steroids your cat is most likely to receive are synthetic hormones known as glucocorticoids. Those most commonly used in felines include dexamethasone, prednisone and prednisolone. These medications break down your cat's store of proteins, fats and sugars, and they're also effective at treating inflammation. If your cat receives steroid therapy, he shouldn't be taken off the drug abruptly but gradually weaned off instead. (Always consult with a qualified vet about the care and welfare of your pet.)


Fluffy might take steroids for reasons ranging from itchy skin to cancer. If he suffers trauma, steroids can relieve the swelling. If he goes into shock, they might improve his blood circulation. His immune system is out of whack? Steroids can suppress a system gone hyperactive. Depending on what's wrong with your cat, steroid treatment can be short or long term. While short-term side effects differ from those of long-term use, increased drinking, or polydipsia in vetspeak, is characteristic of both.

Increased Thirst

If your cat's constantly at the water bowl, keep it full and let him drink. You might think he's consuming too much, but depriving him of water could lead to dehydration. He's thirsty because his medication removes fluids from his body, so he must replace them as best he can. If you're concerned his drinking is out of control, contact your veterinarian for advice.

Other Side Effects

Increased thirst and urination aren't steroid's only side effects. Your cat's appetite also might increase, and he could gain too much weight if you aren't careful. Short-term side effects include lethargy, gastrointestinal upset and vomiting, and an increased susceptibility to infections. If Fluffy's prescribed steroids for the long haul, watch him carefully and check his body regularly. Long-term use can cause wounds to heal slowly; skin issues, including acne; dull coat quality; increase in bacterial infection; and diabetes. Other long-term side effects include formation of calcium deposits on his skin and urinary tract infections. And the steroids might hide the symptoms of urinary tract infections. That means your vet gets to test your cat's urine regularly for signs of infection while he's on steroids.

Always check with your veterinarian before changing your pet’s diet, medication, or physical activity routines. This information is not a substitute for a vet’s opinion.

the nest