Understanding Kidney Disease in Cats
The kidneys play a vital role in filtering waste products from the blood and regulating fluid balance in the body. Cats have two bean-shaped kidneys located in the abdomen along the spine. Each kidney contains thousands of nephrons that filter blood and remove toxins, excess minerals, and metabolic waste products. The filtered blood is then returned to the body while the waste is excreted out through the bladder as urine.
Chronic kidney disease (CKD) is one of the most common kidney diseases in cats. According to research, the prevalence of CKD is around 2-4% in the general cat population but increases to 30-40% in cats over 10 years old [1]. CKD involves the gradual loss of kidney function over time. This can be caused by various factors like congenital abnormalities, inflammation, toxins, or aging. Acute kidney injury, infections, kidney stones, and kidney cancer are some other kidney diseases seen in cats.
Common symptoms of kidney disease in cats include increased thirst, increased urination, weight loss, poor appetite, lethargy, vomiting, and bad breath. As the disease progresses, ulcers in the mouth, anemia, stunted growth, and other issues may develop. Diagnosis involves blood and urine tests to evaluate kidney function, kidney imaging, and sometimes biopsy.
Dietary Changes
Making changes to your cat’s diet is one of the most important ways to support kidney health and function. One of the primary dietary changes is transitioning to a low-phosphorus diet. Phosphorus can build up in the blood when the kidneys can’t adequately filter it out. This leads to secondary hyperparathyroidism, damaging the kidneys further [1]. Feeding a low-phosphorus diet reduces phosphorus levels, slowing the progression of kidney disease.
Increasing water intake is also crucial, as hydration supports kidney function and reduces stress on the kidneys. Adding more canned/wet food or water to dry food can encourage cats to drink more. You can also use cat water fountains. Discuss options with your vet for increasing water intake.
Omega-3 fatty acid supplements may also help reduce inflammation and protect kidney health. Talk to your vet about supplementing with fish oil, krill oil, or other sources of omega-3s [2].
Medications
There are several medications that can help manage kidney disease in cats. Some common medications prescribed include:
ACE inhibitors
ACE (angiotensin-converting enzyme) inhibitors like benazepril (Lotensin) help dilate blood vessels, leading to improved blood flow and decreased pressure in the kidneys. This helps slow the progression of kidney disease. According to PetMD, ACE inhibitors can increase quality of life and survival time in cats with kidney disease.
Antacids
Antacids like famotidine (Pepcid) can help reduce stomach acid production and prevent ulcers, which are common in cats with kidney disease. Controlling nausea and preventing vomiting helps cats maintain their appetite and get proper nutrition.
Anti-nausea medications
Anti-nausea medications like ondansetron (Zofran) and maropitant (Cerenia) can help control vomiting and nausea. This helps cats keep food down and maintain their appetite, which is important for nutritional status. According to Petcarerx, anti-nausea meds are often used in conjunction with antacids.
Subcutaneous Fluids
Subcutaneous fluid administration, also known as subcutaneous fluids or sub q fluids, involves injecting fluids under a cat’s skin to treat dehydration from conditions like kidney disease. Sub q fluids provide a continuous flow of fluids, electrolytes, and nutrients to support kidney function.
The frequency and amount of subcutaneous fluids depends on the cat’s specific needs. According to the Veterinary Centers of America, the typical dose is 50-100 mL every 24-48 hours. However, some cats may require higher or more frequent doses such as 25-50 mL every 8-12 hours.
There are several benefits to administering subcutaneous fluids at home for cats with kidney issues[1]:
- Improves hydration and prevents dehydration.
- Flushes toxins from the body and improves kidney function.
- Helps maintain electrolyte balance.
- Can increase appetite and energy levels.
- May slow the progression of kidney disease.
Subcutaneous fluids are generally very safe and well-tolerated in cats. However, potential side effects include minor skin irritation at the injection site or fluid buildup under the skin. Overall, sub q fluids are an effective way to support kidney health at home when prescribed and monitored by a veterinarian.
Dialysis
Dialysis is a process that filters waste products, toxins, and excess fluid from the blood when the kidneys are no longer able to perform this function adequately. The two main types of dialysis used in cats are hemodialysis and peritoneal dialysis. Hemodialysis involves filtering the blood through an artificial kidney machine, while peritoneal dialysis uses the lining of the abdomen (peritoneum) as a filter to clear waste products.
According to the College of Veterinary Medicine at Purdue University, the most common indication for hemodialysis in cats is acute kidney injury, also known as acute renal failure (https://vet.purdue.edu/hospital/small-animal/services/hemodialysis.php). Hemodialysis may be used in cases of sudden kidney failure from toxins, infections, trauma, etc. It works by circulating the cat’s blood outside the body through a dialyzer, which contains a semipermeable membrane that filters out waste and extra fluid. This helps stabilize kidney function until the kidneys potentially recover.
Peritoneal dialysis is an option for gradual or chronic kidney failure, and involves infusing a special fluid into the abdomen to absorb toxins and remove fluid over several hours while the cat rests comfortably at home or at the vet’s office (BluePearl Vet, https://bluepearlvet.com/medical-articles-for-pet-owners/dialysis/). The fluid is later drained out along with the filtered waste. This type of dialysis is less invasive and can potentially be done at home by owners.
Kidney Transplants
A kidney transplant involves surgically placing a healthy kidney from a donor cat into a recipient cat with kidney failure. Kidney transplants are an option for cats with chronic kidney disease that can no longer be managed effectively with medications and dietary modifications. There are several considerations for kidney transplants in cats:
Candidate screening – The veterinarian will run tests to evaluate the cat’s overall health and determine if they are a good transplant candidate. Cats with diabetes, heart disease, cancer, or other systemic illnesses may not be eligible for a transplant. Blood type compatibility between donor and recipient is critical.
Surgical process – The surgery is performed under general anesthesia. The unhealthy kidneys are typically left in place and the new kidney is grafted into the abdomen. The average surgery time is around 3 hours. Anti-rejection medications must be given lifelong post-transplant. (Penn Vet)
Success rates – With advances in surgical techniques and anti-rejection drugs, success rates have improved significantly. One study showed 1-year survival rates of 93% for transplanted cats. Many cats can live several years after a kidney transplant with good quality of life. However, rejection is still a risk requiring close monitoring.
Herbal Therapy
Herbal medicines derived from plants like astragalus, rehmannia, and milk thistle may help support kidney function in cats with chronic kidney disease (CKD) 1. Astragalus in particular contains compounds that demonstrate protective effects on the kidneys by reducing inflammation and preventing fibrosis2. Some evidence suggests astragalus can help improve kidney function by increasing glomerular filtration rate and reducing proteinuria in CKD patients3.
While many herbal remedies are generally safe when used properly, it’s important to consult with a vet before starting an herbal treatment plan. Some herbs like licorice can interfere with medications commonly prescribed for CKD like steroids. Overdosing certain herbs may also cause side effects like vomiting or diarrhea. Working closely with a holistic vet ensures herbal therapies are tailored to your cat’s needs and regularly monitored.
Acupuncture
Acupuncture involves inserting very thin needles into specific points on the body to stimulate nerve receptors and energy pathways. Research shows acupuncture may help treat kidney disease in cats by improving kidney function, reducing uremic toxins in the blood, and alleviating side effects like nausea and vomiting.
Clinical studies demonstrate acupuncture can significantly increase kidney blood flow and urine production while decreasing kidney inflammation in cats with chronic renal failure. In one study, acupuncture sessions 2-3 times per week for 4 weeks improved kidney values in 19 of 20 cats with kidney disease.1
Look for a certified veterinary acupuncturist to perform treatment. Acupuncture should only be done by experts trained in safe and proper cat acupuncture techniques. You can find accredited practitioners through the International Veterinary Acupuncture Society (IVAS). Treatment plans are customized to your cat’s needs and may also include dietary changes.
Caring at Home
Monitoring your cat’s water intake and urine output is crucial when they have kidney disease. Make sure fresh water is always available and track how much they are drinking each day. Urine clumping litter can help monitor urine output. Look for signs of dehydration like dry gums or skin tenting. You may need to administer subcutaneous fluids at home if your cat is not drinking enough water.
Grooming is also very important as cats with kidney disease can become unkempt. Brush their coat daily to avoid matting and help stimulate blood flow. Clean their face and bottom if needed, as kidney disease can make it difficult for them to groom themselves properly. This can help them feel more comfortable.
Provide plenty of affection and quality time with your cat. The emotional stress of kidney disease can be significant, so give them extra love and reassurance. Keep their routine consistent and make sure they have soft, comfortable places to rest. Avoid sudden changes to their environment. Overall, do what you can to keep them relaxed and content at home.
Prognosis
The prognosis for cats with kidney disease can vary quite a bit depending on the stage and severity of the disease. However, kidney disease is generally progressive in cats and cannot be reversed (VCA hospitals). Once the disease reaches end-stage kidney failure, most cats will only live a few weeks to months even with aggressive treatment (PetMD). Some key considerations for prognosis include:
Life Expectancy: With treatment and palliative care, cats with early stage chronic kidney disease may live upwards of 2 more years. For cats with end-stage kidney failure, life expectancy is typically weeks to months, even with intensive care (Cornell Feline Health Center).
Palliative Care: Options like medications, subcutaneous fluids, diet changes, and supplements can help slow the progression of kidney disease and minimize symptoms. This provides palliative care to maintain a good quality of life for as long as possible (VCA hospitals).
Quality of Life: Assessing pain levels, mobility, appetite, and overall feline functioning is key. Cats who are unwilling or unable to eat, who have uncontrolled pain/discomfort, or who can no longer participate in activities they enjoy may have a poor quality of life that warrants euthanasia (PetMD).
