You may have noticed your cat has developed new symptoms and are concerned about what could be wrong. Perhaps they have been drinking more than before or are losing weight. For cats diagnosed with chronic kidney disease, while there is no cure, there are interventions that can slow the progression and improve your pet's quality of life. This article examines the signs to look out for and the treatment options available.
Understanding the feline kidneys: their crucial role
Every cat has two kidneys located close to the spine, toward the back of the body. The kidneys work hard to produce urine, filter and remove toxins from the body, maintain normal blood pressure, regulate salt levels and fluid balance, and produce a red blood cell production hormone.
The nephrons are the filtering units within the kidneys. They are composed of the glomerulus and the tubules. Once about 60–70% are damaged, one will start to see signs of kidney disease and a toxin build-up.
Overall, the kidneys play many roles in the body. Feline renal health is essential for overall health and well-being, and a cat with later-stage kidney disease is generally quite sickly.
Recognizing symptoms of kidney failure in cats
There are a number of signs of kidney failure in cats you may notice. These include:
- Urinary changes. As the kidneys fail, cats begin to urinate more. To make up for the fluid loss, they drink more. Excess thirst and urination are also called polyuria and polydipsia (PU/PD). They can no longer concentrate urine as they used to, and the urine can appear clear, like water. You might also notice your cat has more accidents around the home and sometimes struggles to "make it" to the litter box. As some cats will also have urinary infections, you might see other signs, including blood or foul-smelling urine.
- Digestive issues. When toxins build up due to the failed filtration system within the kidneys, your cat may stop eating and start experiencing nausea and vomiting. It is not uncommon for diarrhea to occur, too. With time, these changes typically lead to weight and muscle loss (cachexia).
- Oral issues. Uremia, high blood levels of urea and protein, can cause ulcers in the mouth and bad breath. It is sometimes mistaken for dental disease, but periodontal disease should not cause ulceration.
- General deterioration. You will notice your cat does not act like before and seems lethargic and weak. With time, anemia, a low red blood cell count, can occur, causing pale gums and a faster breathing rate. Cats are less interested in grooming and self-care, so they frequently have dull and matted coats.
What causes kidney failure in cats?
It is important to note that kidney failure can either be chronic (progresses over a long time) or acute (sudden onset). Chronic kidney disease is much more common in feline patients, and a high proportion of seniors is affected to some degree.
Some of the more common causes of chronic kidney disease in cats include glomerulonephritis, inflammation within the kidney's filtration membrane; pyelonephritis, a bacterial infection of the kidneys; amyloidosis, a build-up of protein; and cancer, with lymphosarcoma being the cancer most frequently seen within the kidney. Chronic kidney disease will occur in middle-aged to senior cats, though this is not always the case.
A number of underlying diseases can make a cat more likely to develop kidney disease. These include hypertension, diabetes, and chronic urinary infections. Urinary tract infections in cats can occur for a long time, and signs can be missed if the owner is not closely monitoring for changes in litter box habits.
Due to their genetics, some cats are more prone to kidney disease. This is seen, for example, in many Persians who develop polycystic kidney disease because of their DNA.
Acute (sudden onset) kidney disease has different causes; the most common is toxicity. Some of the more frequent toxins involved would include lily flowers, anti-freeze, and human medicines such as NSAIDs.
Other causes of acute kidney failure are urinary tract blockages due to stones or masses, shock, viral infections, such as feline infectious peritonitis, and low blood pressure.
Importance of early detection
Early signs of kidney disease in cats can be more subtle and may be limited to a slight increase in thirst and a small amount of weight loss. The sooner the vet diagnoses your cat with kidney disease, the sooner a kidney-supportive lifestyle can commence. When diagnosed early on and well managed, cats can live longer and experience fewer symptoms.
Diagnosing kidney disease
Diagnosis will consist of a physical exam, history taking, and some initial lab work. Blood tests for cats should include hematology (assessing red blood cells, white blood cells, and platelets) and biochemistry (which looks at the levels of blood urea nitrogen (BUN) SDMA and creatinine, as well as a range of other chemicals within the blood). Urine analysis and culture are also crucial to determine whether the urine is adequately concentrated and check for crystals, bacteria, protein, or blood.
Once blood and urine results have been analyzed, your cat can be assigned a stage or "grade" of kidney disease. Many vets use the IRIS system, which has four stages, with stage four being the most advanced kidney failure.
For some cats, a vet would also recommend imaging such as X-rays or an ultrasound scan, a blood pressure reading, and perhaps a kidney biopsy.
Treating kidney failure in cats
Studies have shown that diet may be the most important factor in managing chronic kidney disease and improving quality of life. Prescription diets are available, and these should be fed exclusively. These cat foods contain restricted protein levels and low phosphorous and sodium. The diet would ideally contain many water-soluble vitamins, fiber, and oxidants. Feeding a wet diet is sensible to help improve hydration levels.
A diet change should be done slowly over several days to avoid stomach upset. As protein-restricted diets can be somewhat unpalatable, it can also help to offer them warm, which releases the aromas and flavors.
In addition to a specific diet, veterinary recommendations for cat kidney failure may include supplements such as polyunsaturated omega-3 fatty acids, B vitamins, and potassium. Cats with kidney disease can lose essential vitamins and minerals through their urine, so sometimes, they need extra help to keep levels adequate.
Kitties with excessively high blood phosphorous levels may be issued phosphate binders to give alongside their meals. These binders reduce the amount of phosphorous the gut can absorb.
Cats with high blood pressure should be provided with medicine to reduce their hypertension, and they may also require medicine to prevent protein from being lost in their urine.
Previously, EPO (erythropoietin) stimulating medicines were used to help combat the anemia that some cats experience. Today, vets are turning to newer generations of drugs, including Molidustat, an oral suspension.
As the disease progresses, vets will turn to more medication to manage signs and improve quality of life. This can include anti-nausea medicine, appetite stimulants, and antacids if a cat develops gut ulcers and inflammation due to the high toxin levels. Any infections that arise would require treatment with antibiotics.
Home care for cats with kidney failure may include subcutaneous fluids*. These are given to improve hydration levels and flush out toxins in the end stage of this disease. Owners may be taught to do this by a vet or vet tech when their cat is no longer able to stay hydrated.
Advanced treatment options
You may have heard about more invasive therapies, such as dialysis or kidney transplants. While these are commonplace in human medicine, they are not widely available in the veterinary world.
Living with kidney failure: supporting your cat
Looking after your cat and keeping them comfortable can sometimes seem daunting, particularly in the first few weeks after diagnosis. You can help your feline friend thrive by following vet recommendations and bringing them for regular check-ups. Try to stick to the prescribed diet when possible and ensure your cat always has plenty of fresh water available.
It can help to keep stress levels low. These cats often need a lot of rest, and offering calm and quiet "hiding places" to sleep in is sensible.
Kidney failure is a common diagnosis in older cats, and with proper intervention and veterinary care, cats can do well for extended periods. Early detection and management are vital for ensuring the best quality of life, allowing patients to live comfortably for months or even years.
FAQ
Can pet insurance cover treatment for cat kidney failure?
Absolutely, insurance is often invaluable for covering the cost of treating kidney failure in cats. Typically, insurance would cover the price of all consultations, investigations, and treatment (including prescription diets). If an owner has opted for a "lifetime policy," the insurance should continue to cover costs until the cat passes.
Is it just old age or could it be kidney failure?
A senior cat with kidney failure may be "missed" by an owner who thinks their pet is just getting old. Some signs of aging, such as a loss of muscle mass and a generalized slowing down, are also signs of kidney failure. However, if your older cat drinks more or is vomiting, this may well mean more is going on.
Is kidney failure in senior cats life-threatening?
Sadly, kidney failure is not something that can be cured, and it will progress over time, regardless of what you do. However, cats can potentially live for many months or even years after a diagnosis, and many senior cats will ultimately die from other causes, not from their chronic kidney disease.
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Kidney failure is common, particularly in middle-aged and older cats. There is currently no cure for it, but there are many things you can do to manage your cat's long-term health condition and ensure they live a full and happy life.
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The most common signs of chronic kidney disease include excess thirst, excess urination, weight loss, reduced appetite, and nausea. These signs are not specific to kidney disease, so a veterinary diagnosis is always required.
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In addition to a renal diet, kidney disease can be managed with medications, including anti-acids, anti-nausea medicine, and appetite stimulants. It is also advised to manage any co-morbidities, such as high blood pressure, proteinuria, or urinary infections.
7 resources
- IRIS: International Renal Interest Society. Diets for cats with chronic kidney disease (CKD) Updated 2022.
- Veterinary Sciences. Feline polycystic kidney disease: an update.
- Merck Veterinary Manual. Table of chronic kidney disease stages.
- Journal of Feline Medicine and Surgery. Feline CKD: pathophysiology and risk factors - what do we know?
- Journal of Feline Medicine and Surgery. Feline comorbidities: the intermingled relationship between chronic kidney disease and hypertension.
- Journal of Feline Medicine and Surgery. Feline acute kidney injury: 1. Pathophysiology, etiology, etiology-specific management considerations.
- Journal of the American Veterinary Medical Association. Pathology in practice.
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