The kidneys serve important functions in your pet’s body—they filter waste products from the blood, maintain fluid, electrolyte, and mineral balances, and contribute to red blood cell production through a complex hormone system. Widespread metabolic turmoil occurs when kidney function declines, because of a condition known as chronic renal failure (CRF) or chronic kidney disease (CKD). CKD is common in aging pets and can significantly affect quality and length of life.

CKD is typically a slowly progressive, chronic disease—as the name implies—but other illnesses can change how the body compensates, and cause a rapidly worsening emergency condition. The Urgent Pet Care Omaha team wants pet owners to recognize early CKD signs, and understand how early detection through wellness screening can vastly improve outcomes and avoid the need for ER visits. Here, we answer your questions about pet CKD.

Question: What is chronic kidney disease in pets?

Answer: CKD is the chronic, slow deterioration in kidney function that results in increased waste product buildup and metabolic changes throughout the body. While the kidneys’ primary function is to filter blood, they also maintain hydration, create red blood cells, and balance important minerals, sugars, proteins, and other substances that create additional problems when they are off kilter.

Q: Which pets are most commonly affected by chronic kidney disease?

A: Older cats and dogs are most likely to acquire CKD, but some younger pets with congenital or inherited conditions may also develop the disease. Older cats are especially at risk—one study found 30% to 50% of cats older than 15 years have CKD. Many underlying disease processes can damage the kidneys, but CKD may not develop until months or years later, and your veterinarian is unlikely to determine the root cause. 

Q: What are chronic kidney disease signs in pets?

A: CKD is classified in stages one through four, and the earliest stages—one and two—rarely cause appreciable clinical signs. Stages three and four may result in the following:

  • Weight loss or muscle wasting
  • Poor appetite, nausea, or vomiting
  • Bad breath
  • Increased urination and thirst
  • High blood pressure that may cause restlessness, vocalization, or blindness

Q: How is chronic kidney disease usually diagnosed?

A: Most people become concerned when they notice the signs listed above and schedule a visit with their veterinarian. Blood and urine tests often reveal increased blood waste products and diluted urine, which indicates CKD, and provides staging information. Tests included in the CKD workup may include:

  • Blood work to check BUN and creatinine waste products
  • Urinalysis and urine protein test
  • Urine culture to check for infection
  • Blood pressure
  • Kidney X-rays or ultrasound

Q: What are the problems with traditional chronic kidney disease diagnosis?

A: By the time pets show changes in their blood work, urinalysis, or blood pressure, or have developed clinical signs at home, 66% to 75% of their functional kidney cells are already lost. This late-stage kidney damage is irreversible, and while appropriate treatment can slow further damage, the disease will progress, and shorten these pets’ life expectancy. 

Earlier disease detection through annual or semi-annual wellness tests can diagnose CKD earlier, but can also be problematic. In early stage CKD, creatinine will begin to creep higher and higher, yet often will remain in the “normal” laboratory-provided range. CKD indicators can also be affected by non-CKD illnesses that cause muscle loss, dehydration, or blood loss, making interpretation of these parameters challenging.

Q: What new options help to detect chronic kidney disease earlier?

A: Veterinarians and researchers developed a new test in 2015 that helps detect disease earlier (i.e., symmetric dimethylarginine [SDMA]), which is now widely available through veterinary reference laboratories. This test has several advantages over traditional diagnostics, including:

  • Better correlation to kidney filtration rate, a direct indicator of kidney function
  • Detects changes earlier at 40% function loss, rather than the 66% to 75% of prior tests
  • Detects changes before clinical signs
  • More reliable—is not affected by weight or hydration

Q: How can early chronic kidney disease detection affect treatment?

A: Diagnosing CKD in early stages allows your veterinarian to implement changes and treatments that will protect the kidneys, reduce their workload, and significantly slow further damage. This treatment usually starts with a special prescription or nutritionist-formulated diet that limits protein intake and balances minerals—especially potassium and phosphorus—so the kidneys don’t have to do this work. Diet has been proven to delay CKD progression up to several years.

In contrast, pets with late-stage disease, in addition to the specialized diet, often require supplemental fluids, medications to lower blood pressure and treat nausea, and supplements to raise potassium and/or lower phosphorus levels. However, although diet is recognized as an effective treatment, many of these pets are unwilling to eat because they don’t feel well, and changing the diet becomes the greatest challenge. Treatment may slow progression for these pets, but they have little kidney function left and will likely succumb to their disease faster than pets diagnosed in early stages.

Q: How often should my pet be screened for chronic kidney disease?

A: The SDMA test should be performed with BUN, creatinine, urinalysis, and blood pressure testing for a full kidney function picture. Annual screening with an SDMA-containing blood profile allows your veterinarian to monitor trends and take action as soon as SDMA becomes elevated.

Early CKD detection can be a game-changer for pets afflicted with this common condition. Pets who are not eating well, drinking more, urinating more, or not acting like themselves may have CKD or another serious underlying illness. Contact us or bring your pet to see the Urgent Pet Care Omaha team during our convenient, extended business hours if you have any concerns about your pet’s health.