--- title: "Kidney disease in cats and dogs: signs and treatment" id: "6189" type: "post" slug: "kidney-disease-in-cats-and-dog" published_at: "2026-08-05T12:08:16+00:00" modified_at: "2026-08-14T04:46:13+00:00" url: "https://rspcapetinsurance.org.au/pet-talk/kidney-disease-in-cats-and-dog/" markdown_url: "https://rspcapetinsurance.org.au/pet-talk/kidney-disease-in-cats-and-dog.md" excerpt: "Kidney disease is a common health condition that often affects older cats and dogs. Because it develops gradually, the early signs can be easy to overlook, especially when they seem like part of the natural ageing process. While only a..." taxonomy_category: - "Health & wellness" --- [Pet Talk](https://rspcapetinsurance.org.au/pet-talk/) [Health & wellness](https://rspcapetinsurance.org.au/pet-talk/category/health-and-wellness/) Kidney disease in cats and dogs: signs and treatment Health & wellness # Kidney disease in cats and dogs: signs and treatment Written by our RSPCA Pet Insurance Team 5 Aug, 2026 - 9 min read Kidney disease is a common health condition that often affects older cats and dogs. Because it develops gradually, the early signs can be easy to overlook, especially when they seem like part of the natural ageing process. While only a vet can diagnose kidney disease, knowing what to look for can help you seek vet advice sooner. Early diagnosis may make it easier to manage the condition, helping your pet maintain a good quality of life for longer. Whether your pet has recently shown signs of kidney problems or you’re simply looking ahead as they get older, this guide explains the early warning signs, how kidney disease may be diagnosed, and what treatment may involve. **Table of contents** - [What is kidney disease in cats and dogs?](#what-is-kidney-disease-in-cats-and-dogs) - [Early signs of kidney disease in cats and dogs](#early-signs-of-kidney-disease-in-cats-and-dogs) - [Signs of advanced kidney disease](#signs-of-advanced-kidney-disease) - [What causes kidney disease in cats and dogs?](#what-causes-kidney-disease-in-cats-and-dogs) - [How kidney disease may be diagnosed](#how-kidney-disease-may-be-diagnosed) - [Treatment and ongoing management](#treatment-and-ongoing-management) - [How pet insurance may help with your pet’s care](#how-pet-insurance-may-help-with-your-pets-care) ## What is kidney disease in cats and dogs? The kidneys perform several important functions, including filtering waste products from the blood, helping to maintain healthy hydration, regulating blood pressure, and supporting the production of red blood cells. When the kidneys are no longer able to function effectively, waste products begin to build up in the bloodstream and affect many aspects of the body. Over time, this can have a significant impact on an animal’s health and wellbeing. The most common form of kidney disease in older pets is chronic kidney disease (CKD). Unlike acute kidney injury, which develops suddenly due to issues such as poisoning, infection, or a urinary blockage, CKD develops gradually over months or even years. Kidney disease is particularly common in older cats, although it can also affect dogs. Because the disease progresses slowly and the early signs can be subtle, it may not be recognised until some kidney function has already been lost. Early diagnosis and appropriate vet care can help support an animal’s health and quality of life. ## Early signs of kidney disease in cats and dogs Because kidney disease develops slowly, the earliest signs are often subtle and may be mistaken for normal ageing. Three of the most common early signs of kidney disease in cats and dogs are: - **Drinking more water than usual** Increased thirst is often one of the first noticeable changes. Some animals may drink more frequently than usual or seek out additional sources of water. - **Urinating more often** Increased urination may result in larger volumes of urine being produced or more frequent toileting. - **Gradual weight loss** Some cats and dogs lose weight even though they continue to eat normally in the early stages of the disease. Because these changes can develop gradually, they’re not always easy to recognise. If you notice your cat or dog drinking or urinating more than usual, or experiencing unexplained weight loss, it’s important to seek vet care. Early diagnosis can help support appropriate treatment and ongoing management. ## Signs of advanced kidney disease As kidney disease progresses and kidney function continues to decline, more noticeable signs may develop. These can include: - Reduced appetite - Lethargy and reduced activity levels - Vomiting or diarrhoea - Poor coat condition - Bad breath, sometimes with an ammonia-like smell - Signs of dehydration despite increased water consumption Some pets may also become less interested in activities they would normally engage in. However, it’s important to remember that these signs aren’t specific to kidney disease. They can also be caused by other health conditions, including diabetes, dental disease or, in cats, hyperthyroidism. A vet examination and appropriate diagnostic tests are needed to determine the cause of these signs. Early assessment can help identify underlying health conditions and support appropriate treatment and ongoing management. ## What causes kidney disease in cats and dogs? In many cats and dogs with chronic kidney disease (CKD), no single cause can be identified. The condition often develops gradually as kidney function declines over time. In some cases, however, kidney disease may be linked to an underlying health condition or previous injury to the kidneys. Potential causes and risk factors include: - Long-term high blood pressure - Dental disease - Certain bacterial or viral infections - Exposure to toxins - Some medications - Inherited or congenital kidney conditions Age is one of the most important risk factors for chronic kidney disease, which is why the condition is more commonly diagnosed in older cats and dogs. Because kidney disease can develop gradually and the early signs may be subtle, it’s not always recognised in its early stages. Regular vet check-ups, including routine blood and urine tests where appropriate, may help detect changes in kidney function before obvious signs develop. ## How kidney disease may be diagnosed The signs of kidney disease can be very similar to those seen with a range of other health conditions, which is why a vet examination and diagnostic testing are needed to confirm a diagnosis. The diagnostic process often begins with a vet examination and a discussion about any changes that have been observed over time. This may include questions about eating and drinking habits, urination and toileting patterns, body weight, activity levels, and other behavioural changes, such as wanting to go outside more frequently than usual. Diagnosing kidney disease involves assessing how well the kidneys are functioning and identifying any changes that may indicate damage or reduced kidney function. To do this, a vet may use a combination of: - **Blood tests** to assess substances that are normally filtered by the kidneys - **Urine tests** to evaluate how effectively the kidneys are concentrating urine and removing waste products - **Blood pressure measurement**, as high blood pressure is commonly associated with kidney disease - **Diagnostic imaging**, such as an ultrasound, to examine the kidneys and look for structural changes The results of these tests help build a picture of an animal’s kidney health and can assist in determining the severity of the disease. In animals diagnosed with chronic kidney disease (CKD), vets may use tools such as the [International Renal Interest Society (IRIS)](https://www.iris-kidney.com/about-1) staging system to determine how advanced the disease is. This information can help guide treatment decisions, monitoring, and ongoing management. Because kidney disease often develops gradually, diagnosis may occur before an animal appears seriously unwell. Identifying the condition early can provide more opportunities to support health, manage complications, and maintain quality of life. ## Treatment and ongoing management Although chronic kidney disease can’t currently be cured, it can often be managed successfully. While existing kidney damage usually can’t be reversed, early diagnosis and ongoing vet care may help slow the progression of the disease and support an animal’s health and quality of life for longer. Many cats and dogs maintain a good quality of life for months, and sometimes years, following diagnosis. Treatment and management will depend on the stage of the disease and the individual animal’s needs, but commonly include a combination of the following: ### A prescription diet Specially formulated kidney-support diets are often one of the most important parts of treatment. These diets are typically lower in phosphorus and contain carefully balanced levels of protein to help manage the effects of reduced kidney function while continuing to meet an animal’s nutritional needs. A vet will provide advice on how to safely and gradually transition a pet to a kidney-support diet. ### Medication Depending on your pet’s condition, medication may be prescribed to help: - Manage high blood pressure - Reduce protein loss through the kidneys - Control nausea or vomiting - Lower phosphorus levels - Support overall kidney function Not every animal will need the same medications, and treatment recommendations may change over time as the disease progresses. Regular monitoring helps vets assess how an animal is responding to treatment and whether any changes to their management plan are needed. ### Fluid therapy As kidney disease advances, some pets may have difficulty maintaining adequate hydration. In these cases, a vet may recommend fluid therapy to help replace lost fluids and support kidney function. ### Ongoing monitoring Managing kidney disease is an ongoing process. Regular check-ups, along with repeat blood and urine tests, help monitor kidney function, assess how the disease is progressing, and identify any changes that may require adjustment to treatment or management. Because kidney disease can change over time, regular monitoring plays an important role in supporting an animal’s health, welfare, and quality of life. ## How pet insurance may help with your pet’s care Because chronic kidney disease is progressive and typically requires ongoing care, treatment costs may accumulate over time rather than being limited to a single expense. With [RSPCA Pet Insurance](https://rspcapetinsurance.org.au/) , eligible health conditions are covered, which can help take some of the financial pressure off ongoing vet visits, tests, and treatment as your pet’s condition is managed. Plus, every policy contributes to vital RSPCA animal welfare initiatives, which means you’re not just protecting your own pet, you’re also supporting animals in need across Australia. To learn more about how RSPCA Pet Insurance could support you and your pet, click [here](https://rspcapetinsurance.org.au/) . Or, if you’re ready to take the next step, you can fetch a commitment-free pet insurance quote [online](https://quote.rspcapetinsurance.org.au/) . ### **Disclaimer** As with any insurance, terms, conditions, and exclusions apply. Please read the [Product Disclosure Statement](https://rspcapetinsurance.org.au/product-disclosure-statement/) to make sure this cover suits your needs. **References** [1] Journal of Feline Medicine and Surgery. *Prevalence and classification of chronic kidney disease in cats randomly selected from four age groups.* Available from: [https://pmc.ncbi.nlm.nih.gov/articles/PMC4414065/](https://pmc.ncbi.nlm.nih.gov/articles/PMC4414065/) [2] International Renal Interest Society (IRIS). *IRIS Staging of CKD.* Available from: [https://www.iris-kidney.com/iris-staging-of-ckd](https://www.iris-kidney.com/iris-staging-of-ckd) [3] RSPCA Pet Insurance. *Product Disclosure Statement.* RSPCA Pet Insurance. Available from: [https://rspcapetinsurance.org.au/product-disclosure-statement/](https://rspcapetinsurance.org.au/product-disclosure-statement/) [4] Cornell University College of Veterinary Medicine. *Chronic Kidney Disease.* Available from: [https://www.vet.cornell.edu/departments-centers-and-institutes/cornell-feline-health-center/health-information/feline-health-topics/chronic-kidney-disease](https://www.vet.cornell.edu/departments-centers-and-institutes/cornell-feline-health-center/health-information/feline-health-topics/chronic-kidney-disease) [5] International Cat Care. *Chronic kidney disease (CKD) in cats.* Available from: [https://icatcare.org/articles/chronic-kidney-disease-ckd-in-cats](https://icatcare.org/articles/chronic-kidney-disease-ckd-in-cats) [6] VCA Animal Hospitals. *Chronic Kidney Disease in Dogs.* Available from: [https://vcahospitals.com/know-your-pet/kidney-failure-chronic-in-dogs](https://vcahospitals.com/know-your-pet/kidney-failure-chronic-in-dogs) [7] VCA Animal Hospitals. *Testing for Kidney Disease.* Available from: [https://vcahospitals.com/know-your-pet/kidney-disease-testing](https://vcahospitals.com/know-your-pet/kidney-disease-testing) [8] International Renal Interest Society. *IRIS Treatment Recommendations.* Available from: [https://www.iris-kidney.com/education/treatment_recommendations.html](https://www.iris-kidney.com/education/treatment_recommendations.html) [9] International Renal Interest Society. *IRIS Treatment Recommendations for CKD (Dogs).* Available from: [https://www.iris-kidney.com/s/IRIS-DOG-Treatment_Recommendations_may-2026.pdf](https://www.iris-kidney.com/s/IRIS-DOG-Treatment_Recommendations_may-2026.pdf) [10] International Renal Interest Society. *IRIS Treatment Recommendations for CKD (Cats).* Available from: [https://www.iris-kidney.com/s/IRIS_CAT_Treatment_Recommendations_-2026.pdf](https://www.iris-kidney.com/s/IRIS_CAT_Treatment_Recommendations_-2026.pdf) ## FAQs ### What are the first signs of kidney disease in cats? The first signs of kidney disease in cats can be easy to miss. Many cats begin drinking more water and urinating more frequently, while some also lose weight gradually, even if they’re still eating normally. Because these changes can look like signs of normal ageing, it’s a good idea to book a check-up with your vet if you notice them. Early diagnosis can help your vet develop a management plan to support your cat’s health and quality of life. ### Is kidney disease in dogs different to kidney disease in cats? Kidney disease in dogs and cats affects the kidneys in much the same way, and many of the signs are similar. Increased thirst, increased urination, weight loss, and lethargy can all occur in both species. However, chronic kidney disease is more common in older cats than in dogs. Regardless of species, early diagnosis and ongoing vet care are important to help manage the condition and maintain your pet’s quality of life. ### How is kidney disease diagnosed and staged in cats and dogs? Your vet may diagnose kidney disease using a combination of a physical examination and diagnostic tests. These may include blood tests to measure kidney function, a urine test, blood pressure measurement and, in some cases, diagnostic imaging such as an ultrasound. If chronic kidney disease is confirmed, your vet may use tools such as the [International Renal Interest Society (IRIS)](https://www.iris-kidney.com/) staging system to determine how advanced the disease is. Staging helps guide treatment and provides a better understanding of how the disease may affect your pet over time. ### Can kidney disease in cats and dogs be cured? Unfortunately, chronic kidney disease can’t be cured, and existing kidney damage usually can’t be reversed. The good news is that many cats and dogs continue to live comfortable lives with the right care. A tailored treatment plan, which may include a prescription diet, medication, and regular vet check-ups, can help slow the progression of the disease and support your pet’s quality of life. ### How can pet insurance help with kidney disease treatment costs? Managing kidney disease often involves ongoing vet visits, diagnostic tests, prescription diets and medication, so treatment costs can build up over time. With [RSPCA Pet Insurance](https://rspcapetinsurance.org.au/) , you may be eligible to claim for these health conditions provided they are covered, which may help reduce the financial burden of managing a chronic condition like kidney disease. And with every policy contributing to vital [RSPCA animal welfare initiatives](https://rspcapetinsurance.org.au/pet-insurance-with-purpose/) , it’s protection with purpose. For your own pet and thousands of others across Australia. To learn more, visit the RSPCA Pet Insurance [website](https://rspcapetinsurance.org.au/) or get a commitment-free quote [online](https://quote.rspcapetinsurance.org.au/) today. As with any insurance, terms, conditions, and exclusions apply. Please read the Product Disclosure Statement to make sure this cover suits your needs. [See more](https://rspcapetinsurance.org.au/faqs/) ## Related blogs [How often does my dog need to visit the vet? Aug 2026 - 8 min read Read blog](https://rspcapetinsurance.org.au/pet-talk/how-often-does-my-dog-need-to-visit-the-vet/) [How to tell if your cat is hurt or in pain Aug 2026 - 5 min read Read blog](https://rspcapetinsurance.org.au/pet-talk/how-to-tell-if-your-cat-is-hurt-or-in-pain/) [Ear infections in dogs: causes, signs, and treatment Aug 2026 - 8 min read Read blog](https://rspcapetinsurance.org.au/pet-talk/ear-infections-in-dogs/)