Chronic Kidney Disease - Holmer Veterinary Surgery

What is Chronic Kidney Disease?

Chronic Kidney Disease (CKD) is the term used when a cat or dog has reduced kidney function but is clinically stable. Chronic kidney failure (CKF) is the end stage of kidney disease.

CKD is a gradually progressive condition that is very common in older cats, (seen less often in dogs) so usually the health of the cat will slowly decline over a period of time, however the rate of this decline can be very variable.

Although CKD is not a curable or reversible disease, with appropriate treatment and supportive care we can maintain good quality of life, potentially for years after initial diagnosis.

Although this page focuses on CKD in cats, the same principles can be applied to the disease in dogs.

What do the kidneys do?

Blood is constantly filtered through the kidneys to remove toxic waste, urine is produced in this process. The kidneys jobs are to:
- Excrete waste products/toxins from the body into the urine
- Regulate electrolyte levels (salts) in the body
- Maintain normal blood pressure
- Produce certain hormones
- Maintain fluid balance in the body
- Maintain the acid balance in the body

What are the signs of CKD?

Signs can be subtle, mild, vague and non-specific which means CKD can be tricky to diagnose in early stages. Because CKD is so common in older cats, it is worth attending “old cat check ups” with your vet so they can detect any of these signs as early as possible. These check ups may include a general examination, weighing your cat, checking their blood pressure, or obtaining urine or blood samples. Signs include:

Signs can be gradual with a slow deterioration over a long period, or very sudden in onset.

How is CKD diagnosed?

How is CKD managed?

If a specific cause for the CKD is found (eg, infection of the kidneys), treatment may be possible to stop disease progression. In most cases however CKD is the consequence of ageing/degeneration, treatment is symptomatic and supportive. Some pets may require initial intravenous fluid therapy for initial stabilisation, with long term treatment aimed at supporting the kidneys and minimising complications. Despite therapy, CKD cannot be reversed and in most cases will also progress over time. The mainstay of long term treatment is DIET

Diet

Dietary management is vital in cats with CKD, and is the only thing proven to prolong lifespan. These diets are often called “kidney” or “renal” diets. There are three main aspects to this:

Water intake - In CKD the kidneys are unable to conserve water, and so despite often drinking more, many cats with CKD become dehydrated. Therefore, a wet tinned/sachet food is preferable to dry kibble, as cats take in the majority of their fluid through their diet. There are also other ways you can encourage your cat to drink more water - we have a separate page on how you can do this.
Protein content - An ideal diet for a cat with CKD should have a moderate protein content. Many of the toxic products that accumulate in the blood in CKD are a result of protein breakdown, and feeding a reduced protein diet will help to minimise this and therefore improve quality of life. Protein restriction has to be performed with care though, as too little protein can be extremely detrimental to general health.
Phosphate restriction - cats with CKD often have high phosphate levels, and so feeding a phosphate restricted diet is important. If the phosphate levels remain high despite a low phosphate diet, then your vet may also prescribe a “phosphate binder” to be added to the food.
Potassium supplementation - Your cat’s diet may also need to be supplemented with potassium, as this can be lost from the body if the kidneys aren’t working as well. Special renal diets will have higher levels of potassium in, but if this is not adequate then additional supplementation is sometimes required.

Other treatments

Blood pressure: Your cat should ideally have his/her blood pressure checked regularly, and may also be started on medicines for high blood pressure if present. High blood pressure worsens kidney disease, and can also cause other issues, such as blindness, if left untreated.
Proteinuria (protein in the urine): If there are high levels of protein in the urine, they may be started on a medicine to treat this. High levels of protein in the urine can damage the kidneys further.
Urinary tract infections: Cats with CKD are also more prone to urinary tract infections which may require courses of treatment.
Symptomatic treatment: Some cats with CKD suffer with loss of appetite, nausea or vomiting, and so symptomatic treatment is sometimes given for this. This means medicines may be given for short periods of times to stop these issues.
Intravenous fluid therapy/hospitalization: Occasionally your cat may need short hospital stays for some fluid therapy if they become dehydrated. If this is happening regularly, we may need to look at more ways to increase their fluid intake at home.