Kidney Failure in Cats
All dogs and cats should have 2 kidneys, just like people. The kidneys play a vital role by eliminating waste products that build up in the body, keeping good products in the body, and managing electrolyte levels and red blood cell production. Kidney failure, also called renal failure, occurs when these jobs are no longer being performed. Continue reading to learn about the types of kidney failure, signs of kidney failure in cats, and available treatment options.
Kidney disease is a very common health problem among senior cats. If left undetected and untreated, kidney disease can eventually lead to a cascade of serious medical problems. Chronic kidney problems are generally incurable. But if cat parents can spot early symptoms of illness, early veterinary attention and good management can help give ill cats a longer and better quality of life.
Kidney disease is not only exclusive to senior cats. Newborn kittens can have them too as a congenital anomaly. Injury to the kidneys, toxins, and infections are also important causes of kidney disease.
Kidney failure, which is the end-stage of kidney disease, occurs when only less than 25% of the nephrons (filtering units of the kidneys) remain functional. When a progressive disease gradually damages nephrons, the intact nephrons compensate in an effort to delay renal failure onset. When the time comes that the compensatory action of the functional nephrons is unable to maintain adequate kidney function, kidney failure occurs.
Types of Kidney Failure in Cats
The two main types of kidney failure in cats are acute kidney failure and chronic kidney failure.
Acute kidney failure is a condition that occurs quickly and is often a result of a toxin ingestion or infection.
Chronic kidney failure is a gradual process and is most common in older animals. Occasionally, very young cats develop kidney failure, which is often the result of a condition they were born with, called congenital kidney failure. Persian cats are prone to a congenital kidney disease called Polycystic Kidneys.
Acute Kidney Failure in Cats
1. Signs of Acute Kidney Failure
Cats with acute kidney failure typically show signs of severe lethargy, vomiting, and reduced appetite. They may be drinking and urinating a lot or not at all.
2. Causes of Acute Kidney Failure
- Toxins - These are the most common causes of AKF in cats. Pesticides and rodenticides, house cleaning products, antifreeze, grapes and raisins, toxic plants (such as lilies, chrysanthemum, and azaleas), heavy metals, and certain medications for humans (ibuprofen, antidepressants, etc.) are highly toxic to the kidneys of cats.
- Trauma or injury to the kidneys
- Shock brought about by too much blood loss, rapid dehydration, hyperthermia (heatstroke), vomiting, diarrhea, and other factors that cause a sudden and significant drop in body fluids
- Insect or snake bites
- Kidney infection (Pyelonephritis)
- Heart failure
- Blockage in any part of the urinary tract that prevents the normal flow and excretion of urine, such as a stone lodged in the urethra of male cats.
- Low blood pressure (hypotension) can reduce the flow of blood to the kidneys.
- Feline Infectious Peritonitis (FIP) and other severe systemic infections
3. Treatment of Acute Kidney Failure
Acute kidney failure is a serious condition. Aggressive and quick treatment to support the kidneys and manage the underlying cause can be life-saving. Treatment typically consists of hospitalizing your cat and keeping them on IV fluids, administering anti-nausea medications, administering antibiotics if needed, and ensuring they receive proper nutrition. The treatment may take days to weeks. Rechecking blood work and urine tests will help your vet monitor your cat’s response to treatment.
Chronic Kidney Failure in Cats
1. Causes and Symptoms of Chronic Kidney Failure
The cause of CKD in cats has not been fully established by experts. However, some renal diseases have been linked to the development of the condition. These include:
- Feline Infectious Peritonitis (FIP)
- Chronic bacterial kidney disease (pyelonephritis)
- Nephrolithiasis (kidney stones)
- Acute kidney injury in which there is permanent loss of nephrons
- Polycystic kidney disease
Older cats are more prone to developing chronic kidney failure. Since this is a slow, progressive process, your cat may not show symptoms immediately. You may notice weight loss or muscle mass loss even though your cat is eating well. You might also notice your cat drinking and urinating more than usual. There will be larger urine clumps or pools in the litter box. It's important to note that diabetes also causes similar symptoms in cats.
2. Diagnosing Chronic Kidney Failure
Early stages of chronic kidney disease can be diagnosed with routine yearly blood work and urine tests before clinical symptoms even develop. If your vet suspects kidney failure, they will recommend basic blood work, urinalysis (urine test), and blood pressure measurements to help diagnose kidney failure, stage the kidney failure, and discuss proper treatments and supportive care.
Kidney failure is staged in 4 levels, with Stage 1 being the mildest and Stage 4 being the most severe.
3. Treatment of Chronic Kidney Failure
Once your vet has diagnosed and staged your cat’s kidney failure, treatment will be discussed. Options can range from medications that lower blood pressure, treatment to reduce protein loss in the urine, intravenous or subcutaneous fluids, potassium replacement, medications to help improve red blood cell levels, and dietary changes.
There are a variety of prescription kidney supportive diets available. These diets can help your cat feel better and live longer, often for years, depending on the stage of kidney failure your cat is experiencing. Since cats can be picky eaters, you may need to try a variety of diets to find one they enjoy, so don’t be discouraged if they refuse a few types!
Encouraging your cat to drink more water will also help support the kidneys. Canned foods contain more fluids compared to dry kibble, so feeding your cat canned food and eliminating the kibble may be recommended. Cats also like to drink from moving water, so purchasing a recirculating water bowl might also entice them to drink more.
Prognosis for Cats with Kidney Failure
The prognosis for cats in acute kidney failure will depend on the underlying cause and the amount of damage to the kidneys. For example, kidney infection that is treated quickly often has a better prognosis than if a cat ingests or is exposed to a toxic substance.
The survival times for cats with chronic kidney disease depend, to a large extent, on the stage of kidney failure at the time of diagnosis. As the kidney failure stage increases, there is a consequent decline in survival rates.
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