What is kidney disease in cats?
Kidney disease, also known as chronic kidney disease (CKD), is a common condition in cats where the kidneys become damaged and struggle to filter waste products from the blood. Over time, waste builds up and causes the kidneys to fail. According to one study, the prevalence of CKD is around 2% to 4% in the general cat population, but increases to 30% to 40% in cats over 10 years old (Marino et al. 2014).
There are two main types of kidney disease in cats:
- Acute kidney injury – Sudden damage to the kidneys causing them to suddenly stop working. This can be caused by ingesting toxins, trauma, or urinary obstruction.
- Chronic kidney disease – Gradual decline in kidney function over months or years. Most common form in older cats. Can be caused by dental disease, high blood pressure, infections, or kidney stones.
Kidney disease is diagnosed through blood and urine tests to measure kidney function and check for waste product buildup. There is no cure for kidney disease, but early diagnosis and prompt treatment can slow progression and extend life expectancy.
Risk factors for kidney disease
There are several factors that can increase a cat’s risk of developing kidney disease:
Age – Older cats are at higher risk for kidney disease. According to one study, the prevalence ranges from 30% in cats 11-14 years old to over 80% in cats over 15 years old (Finch et al., 2016). The kidneys undergo natural age-related changes that reduce their function over time.
Breed predispositions – Certain breeds like Persians, Abyssinians, Siamese, Ragdolls, Burmese, Russian Blues, and Maine Coons seem predisposed to chronic kidney disease (CKD), according to some studies (Roura, n.d.). However, the causes are likely multifactorial.
Existing conditions – Cats with diabetes, hyperthyroidism, dental disease, urinary tract infections, or other illnesses are at higher risk for kidney problems. One study found associations between CKD and hyperthyroidism, vomiting, altered appetite, and dental disease (Finch et al., 2016).
Signs of kidney disease
There are several common signs that may indicate your cat is developing kidney disease. These include:
Increased thirst and urination – One of the earliest signs is increased water consumption and urination. This is due to the kidneys being less able to concentrate urine. You may notice your cat drinking more water and having larger urine clumps in the litter box.
Weight loss – Kitties with kidney disease often experience a loss of appetite and weight loss. This is generally a gradual process. Weighing your cat regularly can help detect weight loss early. Source
Poor appetite – Along with weight loss, cats with kidney issues frequently have decreased appetites. Your cat may eat less food at each meal or show less interest in food overall.
Vomiting – Some cats will start vomiting when their kidney disease progresses. Vomiting may be brought on by buildup of toxins in the blood due to poor kidney function. If your cat starts vomiting, contact your vet.
Catching kidney disease early maximizes treatment options and improves prognosis. Monitoring for these signs, in addition to annual bloodwork and vet exams, can help detect problems sooner. If you notice any of these symptoms, have your cat evaluated by a vet right away.
Diagnosing kidney disease
To diagnose kidney disease in cats, veterinarians will perform a physical exam and look for signs like weight loss, poor coat quality, halitosis, and muscle wasting. They will also run blood and urine tests to evaluate kidney function.
Some common blood tests include a BUN (blood urea nitrogen) test to measure urea levels, a creatinine test to assess kidney filtration, and a phosphorus test to check for mineral imbalances. Increased BUN and creatinine levels along with high phosphorus indicate poor kidney function.
A urinalysis can check for increased urine protein, which signals kidney damage. A urine protein to creatinine (UPC) ratio quantifies how much protein is being lost through the kidneys. Higher ratios over 0.4 indicate kidney disease.
Veterinarians may also run imaging tests like x-rays, ultrasound or CT scans to visualize the kidneys and look for abnormalities. These can help identify causes of kidney disease like cancer, stones or anatomical defects.
By combining a thorough physical examination with diagnostic testing of bloodwork and urinalysis, vets can stage the severity of kidney disease as mild, moderate or severe. Early detection leads to better management of the condition.
Dietary Changes
Making some key dietary changes can help prevent kidney disease in cats. One of the most important is ensuring your cat gets high quality proteins. Protein restriction used to be recommended for cats with kidney issues, but recent research indicates cats benefit from higher protein levels as long as the protein is high quality and digestible, such as animal-based proteins like chicken, turkey, eggs, and fish (Source).
Increasing water intake is also crucial to support kidney health and prevent disease. Feed your cat wet food instead of dry since the high moisture content promotes hydration. You can also add water to dry food to increase moisture. Place multiple water bowls around your home and change the water daily to encourage drinking. Consider getting a cat water fountain since cats prefer flowing water (Source).
Finally, reduced phosphorus intake helps prevent kidney issues. Phosphorus can accumulate in the blood when kidney function declines, so look for cat foods with reduced or moderate levels of phosphorus. Canned food is typically lower in phosphorus than dry food (Source).
Supplements
Certain supplements may help support kidney health and slow the progression of kidney disease in cats.
Omega-3 fatty acids have anti-inflammatory properties and may help reduce inflammation in the kidneys, though evidence is limited (https://www.amcny.org/blog/2017/06/21/supplements-use-cats-diagnosed-chronic-kidney-disease/). Look for fish oil supplements made for cats that provide EPA and DHA fatty acids.
Antioxidants like vitamin E may help reduce oxidative damage to the kidneys. Vitamin E supplements tailored for cats with kidney disease are recommended (https://vetmed.illinois.edu/2023/11/30/ckd-supplements-cats-chronic-kidney-disease/).
Probiotics can help maintain healthy gut flora, which supports the immune system and kidney health. Pick probiotic supplements formulated for cats and adjust dosage based on your vet’s guidance.
Medications
There are several types of medications that can help manage kidney disease in cats:
ACE inhibitors
ACE (angiotensin-converting enzyme) inhibitors like benazepril (Lotensin) help dilate blood vessels and lower blood pressure, reducing stress on the kidneys. Studies show ACE inhibitors can slow the progression of kidney disease in cats (source).
Anti-nausea drugs
Nausea is a common symptom in cats with kidney disease. Anti-nausea medications like ondansetron (Zofran) or maropitant (Cerenia) can provide relief (source).
Phosphate binders
As kidney function declines, phosphate levels can increase. Phosphate binders like aluminum hydroxide (Alu-Cap) or sevelamer (Renagel) can help lower phosphate levels and prevent further kidney damage (source).
At-home care
There are several things you can do at home to help care for a cat with kidney disease and potentially slow down its progression:
- Encourage your cat to drink more water by placing multiple water bowls around the house, using a cat water fountain, or adding water to their wet food. You can also add tuna juice or low-sodium broth to the water to make it more enticing. According to PetMD, dehydration is a serious concern for cats with kidney issues.
- Help your cat groom if they are having trouble doing it themselves. Brush their fur daily if needed and trim mats. Keep their paws and rear end clean.
- Monitor their litter habits to catch any signs of straining, discomfort, or decreased output which could indicate a worsening of kidney function. Place litter boxes in easy to access areas.
Providing attentive at-home care and staying alert to changes in your cat’s condition is important for managing kidney disease.
Regular vet visits
Bringing your cat to the vet for regular checkups and labwork is crucial for monitoring kidney health. Blood and urine tests allow your vet to catch any signs of kidney disease early, before you notice any symptoms. Your vet will look for increases in blood creatinine and BUN levels, as well as dilute urine, which can indicate impaired kidney function.
It’s recommended to have your vet do a baseline senior blood panel when your cat turns 7 years old, and then repeat the tests at least annually. For cats already diagnosed with kidney disease, your vet may want to monitor bloodwork as often as every 3-6 months. This allows tracking of kidney values and making any needed adjustments in care.
Regular vet visits also provide the opportunity to monitor your cat’s overall health and address any other medical issues that arise. Providing ongoing veterinary care helps give your cat the best quality of life possible. Partnering with your vet ensures your cat receives well-rounded preventative care and early treatment when needed.
Sources:
https://www.clarkroadanimalclinic.com/services/cats/blog/kidney-disease-cats
https://www.thrivepetcare.com/thrive-guide/renal-disease-and-the-importance-of-prescreening
Preventing kidney disease
The key to preventing kidney disease in cats is providing excellent care and reducing risk factors. Here are some tips:
Give your cat a high-quality diet low in salt and protein. According to PetMD, high-protein and sodium-rich diets can put excess strain on the kidneys over time. Choose a cat food formulated for kidney health or consult your vet for diet recommendations.
Make sure your cat always has access to fresh, clean water. Increased water intake dilutes toxins and helps maintain adequate urine flow to flush out the kidneys. Consider getting a cat fountain if your cat doesn’t drink enough.
Help your cat maintain an ideal weight. Obesity puts stress on the kidneys and increases the risk of disease. Weigh your cat regularly and watch portion sizes if needed.
Have annual vet checkups to monitor kidney values. Early detection allows for early intervention, which is key for kidney health. Annual bloodwork and urinalysis can identify problems before they progress.
With excellent nutrition, hydration, weight control, and preventative vet care, you can keep your cat’s kidneys healthy and functioning properly for years to come.
