Hydration plays an especially important role in cats with chronic kidney disease. Healthy kidneys concentrate urine and conserve water, but as kidney function declines, that ability is gradually lost. CKD cats produce larger volumes of more dilute urine, which means they lose water more easily and are at constant risk of becoming dehydrated, even when they appear to be drinking normally. Maintaining adequate hydration helps support circulation, preserve remaining kidney function, and assist the kidneys in removing waste products from the bloodstream.
In CKD, dehydration can worsen kidney values and contribute to clinical signs such as lethargy, poor appetite, nausea, and weakness. Reduced blood flow to the kidneys from dehydration can further stress already compromised nephrons, potentially accelerating disease progression. Because hydration status can fluctuate from day to day, even mild dehydration can have a big impact on how a CKD cat feels and how their lab work looks.
Cats with CKD often need more water than healthy cats, but meeting that need can be challenging. CKD cats may struggle to keep up with typical water consumption due to ongoing urinary water loss. Wet food becomes especially valuable in this context, as it provides a consistent source of moisture, and many caregivers add additional water to meals to further increase intake. Some cats also benefit from multiple water stations, fountains, or lightly flavored water to encourage drinking. There was a small study I saw with <20 cats that was not able to prove an increase in hydration level between fountains and bowls, but that advice does seem common online with folks trying to urge their cat to drink.
Signs of dehydration in CKD cats can be subtle at first and may include decreased energy, reduced appetite, dry or tacky gums, and changes in skin elasticity, though skin turgor can be less reliable in older cats. Because dehydration is so common in kidney disease, veterinarians often monitor hydration closely and may recommend fluid support when oral intake alone is no longer sufficient. This can include subcutaneous fluids given at home or, in more severe cases, intravenous fluids in a clinical setting.
Supporting hydration is a core part of managing chronic kidney disease, alongside diet, blood pressure control, and phosphorus management. Just as importantly, addressing hydration is not only about replacing lost fluids but also about understanding why a cat is becoming dehydrated in the first place. In CKD, helping a cat stay consistently hydrated can improve comfort, stabilize lab values, and support quality of life throughout the course of the disease.
Sources:
Hydration
Water, Water Everywhere: Nutrition and Hydration in the Management of Feline CKD - WSAVA 2018 Congress - VIN
Voluntary acceptance of nutrient-enriched water supplement and promotion of water intake in clinically dehydrated cats - PMC
Daily Water Requirements and Needs for Cats
In CKD, dehydration can worsen kidney values and contribute to clinical signs such as lethargy, poor appetite, nausea, and weakness. Reduced blood flow to the kidneys from dehydration can further stress already compromised nephrons, potentially accelerating disease progression. Because hydration status can fluctuate from day to day, even mild dehydration can have a big impact on how a CKD cat feels and how their lab work looks.
Cats with CKD often need more water than healthy cats, but meeting that need can be challenging. CKD cats may struggle to keep up with typical water consumption due to ongoing urinary water loss. Wet food becomes especially valuable in this context, as it provides a consistent source of moisture, and many caregivers add additional water to meals to further increase intake. Some cats also benefit from multiple water stations, fountains, or lightly flavored water to encourage drinking. There was a small study I saw with <20 cats that was not able to prove an increase in hydration level between fountains and bowls, but that advice does seem common online with folks trying to urge their cat to drink.
Signs of dehydration in CKD cats can be subtle at first and may include decreased energy, reduced appetite, dry or tacky gums, and changes in skin elasticity, though skin turgor can be less reliable in older cats. Because dehydration is so common in kidney disease, veterinarians often monitor hydration closely and may recommend fluid support when oral intake alone is no longer sufficient. This can include subcutaneous fluids given at home or, in more severe cases, intravenous fluids in a clinical setting.
Supporting hydration is a core part of managing chronic kidney disease, alongside diet, blood pressure control, and phosphorus management. Just as importantly, addressing hydration is not only about replacing lost fluids but also about understanding why a cat is becoming dehydrated in the first place. In CKD, helping a cat stay consistently hydrated can improve comfort, stabilize lab values, and support quality of life throughout the course of the disease.
Sources:
Hydration
Water, Water Everywhere: Nutrition and Hydration in the Management of Feline CKD - WSAVA 2018 Congress - VIN
Voluntary acceptance of nutrient-enriched water supplement and promotion of water intake in clinically dehydrated cats - PMC
Daily Water Requirements and Needs for Cats