Treating feline chronic kidney disease (CKD) usually is focused around minimizing the effects of reduced kidney function, as there is no cure or proven prevention method in cats. Treatment can improve quality of life, extend longevity of a cat’s life, and provide a fulfilling experience for caregivers and veterinarians.
Diet:
There has been research that shows a correlation between CKD cats on renal diets and longer survival times. A pretty drastic difference between those cats and cats on regular food actually, from single digit months to over a year and a half. The benefits of renal diets appear to be present in Stage 2, 3 and 4 patients, but it hasn’t been proven as much in Stage 1 cats. One benefit of introducing a renal diet to a Stage 1 cat is that they’re usually well enough appetite-wise that they’re more likely to accept the diet change. Other diets with phosphate binders are an option, seemingly better than nothing, but not ideal.
One reservation I guess I have with these findings is, what about the potential downsides of protein restriction such as muscle wasting? In general, older guidance did favor reducing protein intake to help reduce toxins. Nowadays, a more cautious approach is taken and restricting protein too much is a legitimate concern.
Phosphate:
This paper discusses there being strong evidence that dietary phosphate restriction in cats with kidney disease is beneficial. They say cats fed a restricted phosphorus diet show less severe renal changes compared to cats fed normal diets. If your cat won’t accept a renal diet, phosphate binding agents (PBA) can be used, but can also cause poor appetite and counteract the impact a PBA would have had. Nothing proving an increase in longevity with PBAs.
Another reservation with the findings that I personally have is, what happens if phosphorus is restricted too much? Phosphorus contributes to other areas of the cat's body besides the kidneys, so I think we should be mindful of over restriction in early stage CKD.
Other restrictions:
Hypertension (high blood pressure):
High blood pressure is found in a good percentage of CKD cats, with the problem being it targets organs and damages them and contributes to progression. No studies on hypertension directly with longevity, but hypertension is linked to proteinuria (protein in urine) and proteinuria is associated with survival rates in CKD cats. So, indirectly worth treating the blood pressure if found.
Amlodipine seems to be the consensus hypertension treatment for cats as it is effective in reducing the above and is easy to administer.
Proteinuria:
Angiotensin-converting enzyme (ACE) inhibitors reduce hypertension, and improves survival in humans with proteinuric kidney disease. But this should be saved for later stages in cats. Study results of CKD cats taking benazepril did reduce proteinuria but received mixed results on directly increasing longevity. Seems like diet changes in early stage CKD are the consensus, and considering the ACE inhibitors later on.
Dehydration:
Treatment of dehydration is essential. Some tools we have available are improving access to water with fountains (more bowls, etc.), adding water to food, and often in later stages feeding tubes and subcutaneous fluid therapy.
Hypokalemia (low potassium):
A smaller percentage of CKD cats (compared to hypertension) also suffer from hypokalemia, or low potassium in blood. Reduced potassium can cause weakness due to myopathy and could contribute to worsening kidney function. Supplementation is recommended in those cases.
Other:
Metabolic acidosis is common in later-stage CKD and can worsen kidney function, some Stage 3-4 cats may need extra alkalinization, potassium citrate, if their blood pH is low, with careful monitoring to keep values in a safe range. Anaemia also affects many CKD cats and can impact quality of life. Look for underlying causes to be addressed. There are treatments (with more risks) that can be offered in more severe cases.
Treatment of CKD is a progressive condition by nature, but with the right diagnosis and treatment plan, it's certainly possible to improve quality of life and extend longevity.
*Worth noting that the research I looked at for this information was from 2013.
Sources:
Feline CKD: Current therapies – what is achievable? - PMC
Diet:
There has been research that shows a correlation between CKD cats on renal diets and longer survival times. A pretty drastic difference between those cats and cats on regular food actually, from single digit months to over a year and a half. The benefits of renal diets appear to be present in Stage 2, 3 and 4 patients, but it hasn’t been proven as much in Stage 1 cats. One benefit of introducing a renal diet to a Stage 1 cat is that they’re usually well enough appetite-wise that they’re more likely to accept the diet change. Other diets with phosphate binders are an option, seemingly better than nothing, but not ideal.
One reservation I guess I have with these findings is, what about the potential downsides of protein restriction such as muscle wasting? In general, older guidance did favor reducing protein intake to help reduce toxins. Nowadays, a more cautious approach is taken and restricting protein too much is a legitimate concern.
Phosphate:
This paper discusses there being strong evidence that dietary phosphate restriction in cats with kidney disease is beneficial. They say cats fed a restricted phosphorus diet show less severe renal changes compared to cats fed normal diets. If your cat won’t accept a renal diet, phosphate binding agents (PBA) can be used, but can also cause poor appetite and counteract the impact a PBA would have had. Nothing proving an increase in longevity with PBAs.
Another reservation with the findings that I personally have is, what happens if phosphorus is restricted too much? Phosphorus contributes to other areas of the cat's body besides the kidneys, so I think we should be mindful of over restriction in early stage CKD.
Other restrictions:
- Sodium - mixed results, exact impact on CKD unknown.
- Essential fatty acid - studies in dogs decreased hypertension, maintained GFR and increased longevity. No study in cats yet.
- Vitamins - some discussion about vitamin E, C, and beta-carotene reduce oxidative stress, not confirmed via study.
Hypertension (high blood pressure):
High blood pressure is found in a good percentage of CKD cats, with the problem being it targets organs and damages them and contributes to progression. No studies on hypertension directly with longevity, but hypertension is linked to proteinuria (protein in urine) and proteinuria is associated with survival rates in CKD cats. So, indirectly worth treating the blood pressure if found.
Amlodipine seems to be the consensus hypertension treatment for cats as it is effective in reducing the above and is easy to administer.
Proteinuria:
Angiotensin-converting enzyme (ACE) inhibitors reduce hypertension, and improves survival in humans with proteinuric kidney disease. But this should be saved for later stages in cats. Study results of CKD cats taking benazepril did reduce proteinuria but received mixed results on directly increasing longevity. Seems like diet changes in early stage CKD are the consensus, and considering the ACE inhibitors later on.
Dehydration:
Treatment of dehydration is essential. Some tools we have available are improving access to water with fountains (more bowls, etc.), adding water to food, and often in later stages feeding tubes and subcutaneous fluid therapy.
Hypokalemia (low potassium):
A smaller percentage of CKD cats (compared to hypertension) also suffer from hypokalemia, or low potassium in blood. Reduced potassium can cause weakness due to myopathy and could contribute to worsening kidney function. Supplementation is recommended in those cases.
Other:
Metabolic acidosis is common in later-stage CKD and can worsen kidney function, some Stage 3-4 cats may need extra alkalinization, potassium citrate, if their blood pH is low, with careful monitoring to keep values in a safe range. Anaemia also affects many CKD cats and can impact quality of life. Look for underlying causes to be addressed. There are treatments (with more risks) that can be offered in more severe cases.
Treatment of CKD is a progressive condition by nature, but with the right diagnosis and treatment plan, it's certainly possible to improve quality of life and extend longevity.
*Worth noting that the research I looked at for this information was from 2013.
Sources:
Feline CKD: Current therapies – what is achievable? - PMC