Do you have a senior cat that has been diagnosed with kidney disease? Or do you have an outdoor cat that you suspect has exposed herself to toxins? Does kidney disease mean a death sentence for your cat?
The question of kidney failure in cats and life expectancy invariably comes up with renal disease.
There is not an easy answer. Some cats live years after a diagnosis of renal insufficiency while others may only have a couple of weeks.
Determining factors are how advanced the damage is to the kidneys, the cause of failure, and whether your cat has problems in other systems.
We explore the signs and causes of renal disease, diagnosis, prognosis, life expectancy, and various treatment options.
Why does your cat need kidneys?
You may wonder why kidney disease would cause your cat to become so sick. You may know that renal failure is life-threatening but are baffled by why it would ever cause ulcers in your cat’s mouth.
One of the major functions of your cat’s kidneys is to filter waste out of the blood. When urea levels become too high, they are toxic to your cat, causing issues like oral ulcers and vomiting. Cats feel putrid and stop grooming.
The kidneys also function to make urine. As renal function slips, the kidneys fail to concentrate the urine anymore. At first, the cat urinates large amounts and drinks to compensate. Eventually, as function declines further, urinary output decreases.
The kidneys also produce hormones that regulate fluid and sodium levels. Sodium affects several other electrolytes such as potassium. Moreover, the kidneys help stimulate the bone marrow’s production of red blood cells via the hormone erythropoietin.
Several factors can contribute to feline kidney failure
There are several common causes of renal disease in cats. Age and toxins are the most common culprits behind kidney damage in cats, but there are many other factors your veterinarian will look at such as genetics.
- Toxins – Among the everyday household items that are poisonous to your cat’s kidney are your medications such as Ibuprofen (Advil), pesticides, cleaning products, antifreeze,
- Nephritis – Inflammation of the kidneys which can lead to infections; Bacteria and pus are damaging to the kidneys
- Polycystic kidneys – Hereditary in long-haired cats
- Trauma – Hit by a car or a high-rise fall can not only bruise the kidneys but also lead to a ruptured urinary bladder which will also cause the renal shutdown
- Aging changes renal function
- Urethral blockage – A common problem in male cats where a crystal lodged in the urethra prevents them from being able to urinate
- Hyperthyroidism can cause circulatory issues that will put stress on the kidneys
- Rapid dehydration overworks the kidneys and can cause permanent damage
- Heart failure – Circulatory challenges, specifically low blood pressure, damages the kidneys
- Overheating or heat exhaustion – Any rapid changes in fluid levels or circulation can damage a cat’s kidneys
- Amyloids – abnormal proteins build up in organs such as the liver and kidneys disrupting normal function; Hereditary in Siamese types (Siamese, Tonkinese, Burmese), Devon Rex, Oriental Shorthair, and Abyssinian cats
What are the signs of kidney disease?
Like diseases in other organs, early signs of kidney failure are frequently nonspecific, intermittent, and ambiguous. As the disease progresses, signs become more dramatic, and it is easier for your veterinarian to reach a presumptive diagnosis.
Some symptoms are still not awfully specific, so kidney disease becomes a rule out as your medical professional attempts to confirm or disprove his or her suspicions.
- Anorexia or decreased appetite
- Weight loss over time
- Uremic odor to the breath
- Vomiting or nausea
- Sometimes oral ulcers
- Diarrhea with or without blood
- Lethargy – Sluggishness, lack of energy
- Depression – Not much interest in usual activities, may sleep a lot
- Weakness or ataxia (swaying, unable to orient limbs appropriately, falling over)
- Polydipsia/polyuria – Excessive drinking/excessive urination; Often this is an early sign and develops into infrequent urination
There are four stages of kidney disease
Cats progress at varying rates through four stages of chronic renal failure. An owner can easily miss the signs of early kidney disease. Moreover, your cat has lost 70% of kidney function before you see any clinical signs.
Veterinarians grade the severity of kidney compromise by the blood levels of creatinine.
- Stage 1 – Less than 1.6 mg/dl; Cat is not in kidney failure
- Stage 2 – 1.6 to 2.8 mg/dL
- Stage 3 – 2.9 to 5.0 mg/dL
- Stage 4 – Over 5.0 mg/dL
What is the prognosis of cats with kidney failure?
The prognosis of a cat with renal failure depends on many factors. Whether the disease is acute (comes on suddenly in a matter of days or weeks) or chronic (persists for weeks or months often with gradual onset)can play a role.
Acute renal failure can make a cat critically ill and may quickly become fatal. However, prompt treatment can reverse many types of acute kidney disease.
Many cats can cope with chronic kidney disease for a prolonged period, the disease progression giving the animal time to adjust.
However, not treating these cats hastens the deterioration of renal tissue. Treatment of chronic cases of renal failure will not only help your cat live longer but also increase her quality of life.
Underlying Conditions that Worsen the Prognosis in Feline Renal Failure
- High blood pressure or low blood pressure
- Liver failure, hepatic lipidosis
- Heart disease
- Pneumonia or chest trauma
- Hemolytic anemia – Immune system destroys red blood cells
- Sepsis – Overwhelming infection that typically has spread from the abdomen or other source to the blood
- Viruses such as feline leukemia or FIP
Conditions that have a Positive Effect on Renal Disease Prognosis
- Prompt and effective treatment for poisons
- An acute disease that reverses quickly
- Regular fluid administration – Some cats subsist on years of fluids under the skin while others require periodic hospitalizations with IVs
- Adherence to a diet specific to kidney care
Kidney Failure in Cat’s Life Expectancy
How long cats live with kidney failure usually directly correlates with the stage of the disease.
The ranking system goes from stage 1 to stage 4 from least affected to most compromised. Life expectancy is only relevant from stages 2 and upward.
Cats with stage 2 kidney disease at diagnosis live an average of eight and a half years. Those in stage 3 only live on average a little less than two years. However, some cats only live a year and others almost six years.
Stage four renal failure cats have a median survival of 35 days. The median lifespan means an equal number of cats live longer and shorter than a month.
Without an average, it is difficult to tell exactly how wide the range is on these cats. However, most cats in stage 4 kidney failure will probably survive less than two months.
The primary goal of kidney treatment is to delay the progression of renal failure from stage 2 or 3 to stage 4.
How do you confirm a diagnosis of kidney disease in cats?
Diagnosing kidney disease always incorporates a cat’s history to determine possible exposure to various toxins, to determine what signs your cat is showing, and to figure out the duration of illness.
A diagnosis also relies on the cat’s age, breed, and gender, all part of signalment. Signalment will tell a medical person how likely a disease or its variations may be. A couple of examples follow.
Chronic renal disease is not likely in a two-month-old kitten, and a urethral obstruction is possible but not nearly as likely in a female cat as in a tom.
Once the history and signalment produce a reasonable suspicion of renal disease, your veterinarian will perform a blood test and urinalysis. Blood chemistry will detect kidney compromise rapidly.
Elevated urea nitrogen combined with increased creatinine blood levels leads to a presumptive diagnosis of kidney disease. The specific gravity of the urine may be low, indicating a failure to concentrate urine.
Then, the only thing left is to figure out the cause and severity of the kidney dysfunction and whether it is a primary disease or secondary to other issues such as dehydration.
When your veterinarian has all of his or her questions answered, the implementation of a treatment plan will commence.
Can you cure kidney disease?
As mentioned earlier, certain types of acute renal damage are reversible. However, the most common kidney problem in cats, chronic renal insufficiency, has no cure. Nevertheless, cats often do much better than dogs when it comes to living a good-quality life with kidney failure.
The first approach to treatment usually lies in correcting fluid deficits and finding the cause of the assault.
Urethral obstructions and ruptured urinary bladders are life-threatening medical emergencies. Your veterinarian will decompress an obstructed cat immediately and then attempt to clear the blockage.
Your cat may have to be hospitalized for several days with an indwelling urinary catheter and intravenous fluids.
Urinary bladder tears from trauma or an obstruction require fast surgical repair and removing urine from the abdomen.
Toxins benefit from fluids and supportive care.
In rare cases, such as with antifreeze, there is an antidote. Depending on what part of the kidney is affected, there is a chance for regeneration once the damaging substance has been cleared.
Cats with amyloidosis that develop the disease in their kidneys need supportive care like patients with chronic kidney failure.
While cats with amyloids may respond to intravenous fluids and nutritional support, be aware that other problems such as high blood pressure can arise from their underlying condition.
Vet protocols for Feline renal deficiency
Treatment protocols for renal deficiency felines aim to get cats eating and functioning at home with a secondary goal to extend life.
- Intravenous fluids with central IV catheter if necessary – Fluid bags often spiked with electrolytes
- Nutritional support via feeding tube if necessary
- Correct underlying problems – Address urinary blockages or ruptures immediately after stabilizing fluid and electrolyte imbalances
- Treat underlying or concurrent problems such as diabetes, liver disease, cancer, heart failure, and high blood pressure
- Phosphate binders – Helpful as phosphorus builds in kidney failure, causing your cat to possibly leach calcium from the bones. High Phosphorus levels also
- Outpatient care – Nutritional support at home is vital to getting the most out of what kidney function remains; Your veterinarian is likely to recommend a prescription diet specifically for the kidneys and possibly an appetite stimulant if needed
Heart disease poses a unique challenge to kidney disease as cardiac failure makes it impossible for the cat to handle a high volume of fluids. Your veterinarian will juggle the fluid requirements very carefully for your cat.
This video shows you what signs might indicate kidney disease when your cat is not behaving normally.
It reiterates how your veterinarian makes a definitive diagnosis and some of the supportive measures that will help your cat get the most out of his failing kidneys for years to come.
Most of the focus in the video is on chronic kidney failure in older cats.