Introduction
Kidney failure in cats, also known as chronic renal failure, happens when a cat’s kidneys can no longer properly remove toxins and waste products from the blood. The kidneys filter waste products, excess minerals and fluids from the blood so they can be excreted through urine. When the kidneys are damaged or diseased, they cannot adequately filter the blood, leading to a buildup of waste products and a dangerous chemical imbalance in the body. This can be an acute condition that comes on suddenly, or a chronic condition that develops gradually over time.
Kidney failure is most common in older cats, but cats of any age can develop kidney problems. The overall chance of a cat surviving kidney failure depends on the underlying cause, how early it is caught, and how aggressively it is treated. With prompt veterinary care and proper management at home, cats can live comfortably with chronic kidney disease for months to years. However in acute cases or end-stage disease, the prognosis is more guarded.
Causes
Some common causes of kidney failure in cats include:
- Infections – Infections like pyelonephritis (kidney infection) can cause inflammation and damage to the kidneys. This is often seen in younger cats.
- Toxins – Exposure to toxins like antifreeze (ethylene glycol), lilies, grapes/raisins, insecticides, heavy metals, and many human medications can be toxic to a cat’s kidneys. These can cause acute kidney injury.
- Congenital disease – Some cats are born with polycystic kidney disease or renal dysplasia leading to chronic kidney failure early in life. This is an inherited disease in cats.
- Kidney stones – Crystals and stones forming in the kidneys and urinary tract can cause obstructions leading to kidney damage. This is more common in male cats.
- Chronic kidney disease – Older cats can develop chronic kidney disease leading to slower progressive kidney failure. This is one of the most common causes in older cats.
Kidney infections, toxins like antifreeze, and congenital kidney diseases are some of the most common causes of acute kidney failure in cats that need prompt veterinary treatment.
Symptoms
The most common symptoms of kidney failure in cats include increased thirst, increased urination, weight loss, and vomiting 1. As the kidneys lose their ability to concentrate urine, the cat will become increasingly thirsty and drink more water. This leads to increased urination as the extra water is excreted. Despite drinking more, cats with kidney failure tend to lose weight as they struggle to maintain proper nutrient balance and metabolism. Vomiting is another common symptom, as toxins build up in the blood due to the kidneys’ inability to filter waste products effectively.
Diagnosis
There are several tests vets use to diagnose kidney disease in cats. The most common are blood and urine tests which measure levels of waste products like blood urea nitrogen (BUN) and creatinine to estimate kidney function. Elevated levels indicate the kidneys are not adequately filtering waste from the bloodstream (VCA Animal Hospitals).
Urinalysis evaluates the concentration of urine to detect impaired kidney function. It also checks for excess protein lost in the urine, which is a sign of kidney damage (Cornell Feline Health Center).
Imaging techniques like x-rays, ultrasound, or CT scans allow vets to visualize the kidneys and look for abnormalities. These help determine the underlying cause and extent of damage. Biopsies are occasionally done to examine kidney tissue and definitively diagnose certain kidney diseases (PetMD).
Treatment
Treatment for kidney failure in cats focuses on several areas including fluids, medications, dietary changes, and dialysis. According to the VCA Animal Hospitals, the main treatments for CKD aim to resolve specific abnormalities identified through blood tests.
Fluids help to correct dehydration and flush toxins from the body. Cats with kidney disease are often dehydrated and require supplemental fluids. This is often done at home by the owner who learns how to administer subcutaneous fluids. According to Cornell University’s Feline Health Center, intravenous fluids can also help correct dehydration and support kidney function.[1] [3]
Medications may be prescribed to control vomiting, lower blood pressure, regulate electrolytes, and decrease the workload on the kidneys. Phosphate binders are commonly used to lower phosphorus levels. According to South Wilton Veterinary Group, ACE inhibitors help dilate blood vessels to maintain proper blood flow.[2]
Dietary changes involve feeding a kidney diet lower in protein, phosphorus, and sodium. The VCA states that prescription kidney diets help reduce the workload on the kidneys. Cornell’s Feline Health Center notes that potassium and vitamin D are often supplemented in the diet.[1] [3]
Dialysis like hemodialysis removes waste from the blood and may be used in severe kidney failure. However, it requires anesthesia so is used cautiously in cats. The VCA states that due to expense and stress, dialysis is uncommon for cats.[1]
Prognosis
The prognosis for cats with kidney failure depends greatly on the underlying cause and how early treatment is started. Acute kidney failure often has a better prognosis if treated promptly, while chronic kidney failure is progressive and incurable. According to the Cornell Feline Health Center, with treatment and supportive care the prognosis for cats with chronic kidney disease is often 6 months to 2 years1. However, cases caught and managed early have a better prognosis and may live 18 months to 3 years. Untreated chronic kidney failure typically leads to death from uremia within weeks to a few months.
For acute kidney injury, the prognosis varies widely based on the underlying cause. With prompt treatment, cats can often recover normal or near-normal kidney function. However, severe damage to the kidneys may still result in chronic kidney disease later on. According to VCA Hospitals, the prognosis is good if the cause can be treated, fair if the cause cannot be determined, and grave if the cause cannot be treated2. Overall, the earlier kidney failure is detected and treated, the better the prognosis.
Survival Rates
According to a study published in Veterinary Journal, the survival rates for cats with chronic kidney disease vary depending on the stage of the disease:
- Stage 1 – Median survival time of 2 years
- Stage 2 – Median survival time of 15 months
- Stage 3 – Median survival time of 7 months
- Stage 4 – Median survival time of 2 months
Another study found the 1-year survival rate was 65% for cats with IRIS stage 2 and 3 chronic kidney disease. The 6-month survival rate was 81%.
So in general, cats with early stage kidney disease have better prognosis and survival times of 1-2 years or longer. But in late stage kidney failure, median survival time declines to just 2-7 months. Proactive treatment and care can help prolong life expectancy.
Quality of Life
Managing pain and maintaining a good quality of life are crucial when treating cats with chronic kidney disease (CKD). Some tips for improving quality of life include:
Monitoring for signs of pain and discomfort – changes in behavior, decreased activity, altered gait, less grooming, altered appetite, vocalizing, etc. Discuss pain management options with your vet such as NSAIDs, gabapentin, tramadol, etc. Keeping your cat comfortable is important.
Regular labwork and checkups to monitor kidney values and address any changes. Your vet may recommend supplements, diet changes, subcutaneous fluids, etc. to help slow disease progression.
Providing excellent at-home care with a kidney-friendly diet, easy access to fresh water, litter box cleanliness, warmth and soft bedding, grooming help if needed, and mental stimulation/enrichment. Assist with medications and sub-q fluids as recommended by your vet.
Work closely with your vet to continually assess quality of life and make adjustments to maximize comfort. Share any observations or concerns about changes in behavior, appetite, litter habits, mobility, grooming, etc. Stay attuned to your cat’s daily needs and experience.
Prevention
There are some steps cat owners can take to help prevent kidney disease in their feline companions:
Get annual veterinary exams. Cats are very good at hiding illness, so annual exams allow vets to check for early signs of kidney disease through bloodwork and urinalysis. Catching kidney disease early greatly improves prognosis and treatment options.
Feed a kidney supportive diet. There are prescription and over-the-counter cat foods formulated to support kidney health, with reduced protein, phosphorus, and sodium levels. Feeding one of these diets, especially to senior or at-risk cats, can help reduce workload on the kidneys. According to Aspca Pet Insurance, kidney-friendly diets can reduce renal workload by up to 40%.
Avoid toxins. Keep cats away from toxins like antifreeze, chemicals, onions, grapes/raisins, and lilies, as these can damage kidneys. Make sure litterboxes are kept clean and free of chemicals. Use natural cleaning products and ensure cats don’t have access to areas cleaned with harsh chemicals.
Conclusions
In summary, kidney failure is a serious condition, but cats can live for years with proper management and care. The key is to catch kidney disease early and start treatments like dietary changes, IV fluids, and medication. Regular vet checkups and bloodwork are important, especially for senior cats. With early detection and treatment, many cats can live a good quality of life for years.
The most important takeaway is not to wait until symptoms appear, as that indicates the kidneys are already badly damaged. Getting annual bloodwork and urinalysis starting at age 7 helps find problems at an early, treatable stage. Cats on kidney diets and medications as soon as kidney disease is detected tend to live the longest. Work closely with your vet and follow their treatment plan for the best chance of survival.
While kidney failure shortens lifespan and requires care, it is very manageable if caught early. With dedicated owners providing quality care and proper treatment, cats can live happily for years with this condition. The prognosis depends on each cat’s individual case, but early detection and treatment provide the best odds.