Podcast Transcript: Feline Chronic Kidney Disease
Chronic Kidney Disease, or CKD for short, is a common cause of illness and death in aging cats. It is so common that almost one of every twelve geriatric cats seen at Banfield in 2010 had CKD.
Although the prevalence of the disease appears to be steadily increasing over the years, we can't be sure whether this increase is due to our improved ability to detect CKD, or to other factors.
The clinical signs of CKD such as polyuria polydipsia, loss of appetite, and weight loss are largely attributable to the severely reduced capacity of the kidneys to do their job. As a result, waste products such as urea nitrogen and creatinine, which are usually excreted by the kidneys, accumulate in the bloodstream and electrolyte imbalances develop.
Because the damage associated with CKD is progressive and irreversible, there's a need to identify ways to either prevent or at least slow that damage so effected cats can have the best possible quality of life, given the circumstances.
We also need to better understand what causes the disease in the first place. No one diagnostic test can say for sure whether a live cat does or does not have CKD. Complete history-taking, full blood work, and urinalysis remain the best way to detect it. For this reason, semiannual, or at the very least annual, comprehensive examinations for cats, eight years of age and older, are strongly recommended. Asking questions about the cat's general health may help to identify susceptible or effected cats by revealing risk factors for the disease.
Increasing age is the factor consistently shown to predict development of CKD in healthy cats. Breed, sex, and dietary components such as protein and phosphorus content have been investigated as a risk factor, but findings have not been consistent. Hyperthyroidism and hypertension have also been linked to CKD, but it's unclear whether these diseases precede CKD, develop concurrently, or result from CKD.
Other factors that should trigger alarm bells are increased water consumption or urination which are things that a cat's human family would likely notice.
Regular testing of serum creatinine concentration in urine specific gravity can help to identify kidney disease in its early stages, before a cat's quality of life begins to suffer.
We don't know what degree of change in creatinine signals as CKD is present, but evidence indicates that a urine specific gravity of less than .035 and creatinine concentration of greater than 1.6 mg/dL are highly suggestive.
Another measure that may help is the ratio of urine protein to creatinine or urine albumin to creatinine. Lower ratios have been shown to predict a better prognosis in cats with CKD. Indeed, effected cats with a protein to creatinine ratio of less than .43 reportedly lived more than twice as long as effected cats with higher ratio. Other tests such as measurement of urinary retinol-binding protein, plasma iohexol clearance, or exogenous creatinine clearance may be useful, but more information is needed on the accuracy of these tests for detecting CKD specifically.
Although detecting CKD in its early, rather than the late stages, would be the ideal, we're not at a point where we have enough information to make this job easy. The disease is of high enough prevalence to justify annual to semiannual checkups for all middle-aged and geriatric cats.
Through regular physical examinations, history taking, and serial blood and urine testing, veterinary professionals have the opportunity to spot disease early and provide their patients with the best possible prognosis.
This podcast was created and developed by Banfield Pet Hospital and is brought to you by the Banfield Applied Research and Knowledge team. For additional content, or to view the whitepaper for this topic, please visit Banfield.com.
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