Chronic Kidney Disease (CKD) in Dogs

What Is Chronic Kidney Disease (CKD) in Dogs?

Dogs have two kidneys, which are vital for maintaining life’s day-to-day processes. They have a variety of functions, the foremost of which is to filter and excrete toxins and waste from the body. Other tasks of the kidneys include regulating fluid, mineral, and electrolyte balance; conserving water and protein; maintaining blood pressure; and producing red blood cells. 

Many causes are associated with progressive loss of kidney function, and unfortunately, once lost the damage is irreversible. As a result, unfiltered waste products and toxins build up in the bloodstream, leading to a generalized state of nausea and malaise. When left untreated or unmanaged, a dog’s quality of life suffers. Early diagnosis and intervention are vital to managing the disease and maintaining your dog’s comfort and well-being.

CKD is a progressive disease that has often been present for some time before it is diagnosed. It is typically classified into four stages, based on laboratory values and clinical signs:

• Stage I: No clinical signs are seen.

• Stage II: Some clinical signs are seen.

• Stage III: Many clinical signs are seen, and pets often feel sick.

• Stage IV: The majority of clinical signs are seen, often as an emergency. The quality of life for the pet is poor. 

Is Chronic Renal Failure the Same Thing as Chronic Kidney Disease?

Chronic kidney disease (CKD), renal insufficiency, and chronic renal failure (CRF) are different terms often used interchangeably to describe declining kidney health—where over time the kidneys become less efficient in their required tasks and the results are life-threatening.

Symptoms of CKD in Dogs

Dogs typically won’t experience any symptoms until the kidneys have lost about 75% of their functioning capacity. The higher the stage (meaning the greater the extent of kidney disease present), the more symptoms are exhibited.

Dogs in any stage can experience the following symptoms:

• Anemia (low red blood cell count)

• Changes in urine output, usually increased

• Decreased appetite

• Dehydration

• Increased thirst

• Muscle wasting

• Nausea

• Oral ulcerations (sores in the mouth) and bad breath

• Pale gums

• Poor coat appearance

• Sporadic vomiting

• Vision loss, often attributed to secondary hypertension (high blood pressure)

• Weakness and lethargy

• Weight loss

Causes of CKD in Dogs

Chronic renal failure by definition is a disease that occurs over a period of time; it is an ongoing, progressive, and irreversible process where, for some dogs, the cause remains unknown despite extensive testing.

Often CKD develops after a serious kidney injury such as from a severe infection (e.g., leptospirosis, tick-borne disease, or pyelonephritis), heat stroke, envenomation (from a venomous bite or sting), or the ingestion of toxic substances like antifreeze, NSAIDs (ibuprofen), or certain antibiotics. CKD is also associated with certain types of immune-mediated diseases or cancer.

Dogs breeds commonly prone to CKD include:

• Basenji

• Bernese Mountain Dog

• Boxer

• Bull Terrier

• Cairn Terrier

• Cavalier King Charles Spaniel

• Cocker Spaniel

• English Cocker Spaniel

• Shar-Pei

• West Highland White Terrier

How Veterinarians Diagnose CKD in Dogs

A veterinarian will start with a physical exam, bloodwork, and a urinalysis to look specifically at kidney values such as:

• Blood urea nitrogen (BUN): higher values correlated with kidney failure

• Calcium

• Creatinine (CREA): indicator of the kidney’s ability to filter wastes from blood

• Electrolytes: sodium, potassium, chloride

• Phosphorous: higher phosphorus levels seen with CKD

• Red blood cell count: low red blood cell counts are often seen secondary to CKD

• Symmetric dimethylarginine (SDMA): an indicator used for early detection of kidney disease

• Urine specific gravity: determines the kidney’s concentrating ability; the more concentrated the urine is, the greater the ability of the kidneys to conserve water

Your veterinarian may also recommend additional testing such as:

• A urine protein to creatinine (UPC) ratio to determine how much protein is lost in the urine (termed proteinuria)

• A urine culture, as dogs with CKD are more likely to acquire urinary tract infections

• A blood pressure evaluation, as dogs with CKD often have hypertension (high blood pressure)

• Radiographs or abdominal ultrasound to screen for kidney stones, tumors, or infarcts (areas of dead tissue)

Treatment of CKD in Dogs

CKD is a manageable but incurable disease—since by the time dog is symptomatic, irreversible damage has already occurred. Recommendations based on the stage of CKD will be tailored to match your dog’s needs, with dogs in Stage III or IV warranting greater care and therapy than dogs in Stage I or II. Common therapies for CKD include medications, diet, and fluid therapy, along with treatment for any underlying condition or inciting factors.

Medications such as Cerenia®, ondansetron, or omeprazole can help aid nausea, vomiting, and lack or loss of appetite. For some dogs with more extensive needs, a feeding tube may be placed. Additionally, appetite stimulants such as capromorelin and mirtazapine may be recommended.

Most vets will prescribe dietary management with a balanced diet that is lower in protein, salt, and phosphorus and is alkalinized to help combat side effects associated with CKD. Recommended diets typically include:

• Royal Canin® Renal Support

• Hill’s® Prescription Diet k/d

• Purina® Pro Plan Kidney Function Diet NF

Fluid therapy is essential. Fluids will flush out toxic waste substances that the kidneys should be doing on a routine basis and restore hydration. They can be given intravenously in the hospital or subcutaneously (underneath the skin) at home. Your dog should have access to fresh water at all times—a water fountain can be an especially important item to add to your home.  

Recovery and Management of CKD in Dogs

CKD is a serious lifelong condition that requires ongoing care and monitoring as symptoms continue to develop. Dogs with CKD require more frequent veterinary visits and testing than others, and at all stages of CKD, quality of life should be assessed as symptoms change. Be sure to adhere to your veterinarian’s recheck guidelines and continue all medications and diet as recommended; many will be required for life. 

Depending on the circumstances, certain measures can help keep your dog comfortable and offer a good quality of life for as long as possible. Similar treatment and medications to those outlined above also are applicable for long-term management of CKD in dogs, such as:

• Dietary supplements such as Azodyl™, a pre/probiotic, that can help decrease waste products not eliminated by the kidneys.

• Other supplements, such as aluminum hydroxide and Epakitin®are geared to aid with low potassium and high phosphorus.

• Anti-nausea and anti-emetic (anti-vomiting) medications can be prescribed as needed for dogs who experience intermittent vomiting and lack of appetite. 

Unfortunately, given the severity of symptoms often experienced by dogs with Stage III or IV and the extensive amount of care and effort they require, euthanasia may be the best option.