Signs of Kidney Failure in Cats: What Pet Owners Should Know
Chronic Kidney Disease (CKD) in cats is a progressive and common condition, particularly in aging felines. It is defined by functional or structural impairment of one or both kidneys for at least three months. Since healthy kidneys perform vital functions like filtering waste, regulating acid-base balance, and producing hormones, their failure significantly affects a cat’s health over time.
When Do Symptoms Begin to Appear?
Cats don't usually show symptoms until more than two-thirds of their kidney function is compromised. Because kidney tissue has significant reserve and redundancy, clinical signs may go unnoticed in the early stages of the disease.
Early Signs of Kidney Disease in Cats
- Increased thirst (polydipsia)
- Increased urination (polyuria)
- Gradual weight loss
- Appetite loss (anorexia)
These symptoms arise because the kidneys lose their ability to concentrate urine, leading to fluid loss and dehydration, which then stimulates thirst as a compensatory mechanism.
Advanced Symptoms of Chronic Kidney Failure
As CKD progresses, more noticeable and severe signs can develop including:
- Vomiting and nausea
- Dehydration (evidenced by dry gums, sunken eyes)
- Poor coat quality and muscle wasting
- Lethargy and weakness
- Halitosis (bad breath), often smelling like ammonia
- Oral ulcers
- Anemia (seen as pale gums and rapid heart rate)
- Hypertension (which can result in sudden blindness or even seizures)
- Gastrointestinal issues such as diarrhea, constipation, or drooling
- Behavioral changes such as hiding or reduced activity
Severe and Late-Stage CKD Symptoms
Cats in the end stages of kidney disease may show profound neurologic symptoms:
- Disorientation
- Head pressing or stumbling
- Seizures
- Coma
These signs result from the accumulation of toxins in the bloodstream that would normally be filtered by healthy kidneys.
Risk Factors and Causes
Several factors contribute to CKD in cats:
- Genetics – Common in breeds like Persians, Abyssinians, Russian Blues
- Chronic infections – Especially pyelonephritis
- Exposure to toxins – Such as lilies or antifreeze
- High blood pressure (hypertension)
- Old age – Over 30-40% of cats above 10 years old and 80% over 15 may develop CKD
Some cats develop the disease idiopathically—meaning there's no identifiable cause despite thorough diagnostics.
Diagnostic Indicators
Diagnosis of CKD is made based on a mix of clinical signs, lab results, and imaging:
- Bloodwork – Elevated BUN, Creatinine, SDMA, and Phosphorus
- Urinalysis – Diluted urine with protein or infections
- Blood pressure measurements
- Imaging – Ultrasound or X-rays to check kidneys
- Complete blood counts and urine cultures
Stages of Kidney Disease
The International Renal Interest Society (IRIS) categorizes CKD into four stages based on markers like Creatinine and SDMA levels. These are further sub-staged according to proteinuria and hypertension, helping veterinarians tailor the treatment plan effectively.
Managing CKD in Cats
While CKD is not curable, a wide range of treatment options focus on:
- Slowing disease progression
- Managing symptoms and complications
- Maintaining hydration and quality of life
Key Management Strategies
- Therapeutic kidney diet – Low in protein and phosphorus
- Hydration support – Including wet food, water fountains, or subcutaneous fluids
- Medications – To control blood pressure (e.g., Amlodipine), reduce nausea (e.g., Maropitant), and manage electrolytes
- Anemia treatment – Iron supplements or erythropoietin-stimulating agents
- Regular monitoring – Blood tests, urinalysis, and blood pressure every 3 to 6 months
Prognosis and Quality of Life
The prognosis for cats with CKD varies. Early-stage cases managed proactively can maintain reasonable quality of life for months to years. Factors like anemia severity, presence of proteinuria, and response to treatment influence prognosis significantly.
Prevention and Early Detection
Regular veterinary visits are essential, especially for older cats. Early blood and urine screening help detect CKD before symptoms arise. Avoiding nephrotoxins like lilies and some medications can also play a preventive role.
In conclusion, knowing how a cat behaves when kidney failure sets in helps pet owners take swift action. Cats often hide their discomfort, so recognizing these signs early and seeking veterinary care can greatly improve their longevity and comfort.
