When you take your dog for its annual veterinary checkup,you might wonder:if your dog appears perfectly healthy,why does the vet still recommend blood tests and urine analysis?In fact,in these cases,the veterinarian is working to screen for signs of disease that haven't yet shown clinical symptoms,and canine kidney disease is a prime example.

Acute(sudden onset)kidney disease usually presents with obvious symptoms,while canine chronic kidney disease progresses gradually over time—its early signs and symptoms are often difficult to detect.

Early diagnosis and intervention are crucial for controlling disease progression and maintaining your dog's comfort and health.

What is Canine Chronic Kidney Disease?

Canines have two kidneys,both of which play an indispensable role in maintaining their daily lives.The kidneys perform many physiological functions,the most critical being filtering and excreting toxins and metabolic waste from the body.In addition,the kidneys are responsible for regulating fluid,mineral,and electrolyte balance,retaining water and some blood proteins,maintaining stable blood pressure,and producing red blood cells.

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Multiple factors can lead to a gradual decline in kidney function in dogs;unfortunately,once kidney function is lost,the damage is irreversible.The direct consequence is that unfiltered waste and toxins accumulate in the blood,causing nausea and general malaise in dogs.Without timely treatment or control measures,the dog's quality of life will be severely affected.

Canine chronic kidney disease(CKD)is a progressive disease that usually exists for some time before diagnosis.The rate of disease progression varies from dog to dog,making precise prediction difficult.Clinically,veterinarians typically classify CKD into stages I to IV based on laboratory test results and clinical signs(symptoms).

Symptoms of Canine Chronic Kidney Disease

Generally,dogs do not show any obvious symptoms until approximately 75%of their kidney function has been lost.The higher the CKD stage(i.e.,the more severe the kidney disease),the more symptoms may appear;as the disease progresses,the severity and complexity of the symptoms may further increase.

Symptoms of canine kidney failure are diverse,but may primarily include:

-Anemia(low red blood cell count)

-Changes in urine output,usually manifested as increased urination

-Decreased appetite

-Dehydration

-Increased thirst

-Muscle atrophy

-Nausea

-Oral ulcers and halitosis

-Pale gums

-Poor coat condition

-Intermittent vomiting

-Vision loss,usually caused by secondary hypertension

-Weakness,lethargy,and somnolence

-Weight loss

Etiology of Canine Chronic Kidney Disease

Chronic kidney failure is defined as a progressive,continuous,and irreversible pathological process that develops gradually over time.In many dogs,the cause of chronic kidney disease remains unclear despite thorough examination.

In some cases,chronic kidney disease in dogs can occur after severe kidney damage,such as severe infections(e.g.,leptospirosis,tick-borne diseases,or pyelonephritis),heatstroke,venom poisoning(e.g.,snake bites or stings),or ingestion of toxic substances(e.g.,antifreeze,the nonsteroidal anti-inflammatory drug ibuprofen,and certain antibiotics).

Furthermore,chronic kidney disease may also be associated with certain types of immune-mediated diseases or cancer.

Dog breeds prone to chronic kidney disease(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 Canine Chronic Kidney Disease

The veterinarian will first perform a physical examination,blood tests,and urinalysis,focusing on the following indicators:

-Blood Urea Nitrogen(BUN):Elevated BUN levels may be associated with kidney failure.

-Calcium:Although elevated calcium levels are not common,they may occur as the disease progresses.

-Creatinine(Cr or Creat):A key indicator reflecting the kidneys'ability to filter waste products from the blood.

-Electrolytes:Including sodium,potassium,and chloride.

-Phosphorus:Elevated phosphorus levels may be present in dogs with chronic kidney disease.

-Red Blood Cell Count:A decreased red blood cell count is often a secondary symptom of more severe chronic kidney disease.

-Symmetric dimethylarginine(SDMA):A key indicator for early detection of kidney disease

-Urine specific gravity:Reflects the kidney's concentrating function.Generally,a lower urine specific gravity and thinner urine may indicate kidney disease—because healthy kidneys should be able to reabsorb water and concentrate urine to prevent dehydration.

Veterinarians may also recommend the following additional tests to further clarify the diagnosis:

-Urine protein/creatinine ratio(UPC):Used to determine the amount of protein lost in the urine(i.e.,proteinuria)

-Urine culture:Because dogs with chronic kidney disease are more prone to urinary tract infections,urine culture is needed to rule out infection.

-Blood pressure assessment:Dogs with chronic kidney disease often have high blood pressure,requiring regular blood pressure monitoring.

-X-ray or abdominal ultrasound:Used to screen for kidney stones,tumors,or infarction(areas of necrotic tissue).

-Kidney biopsy:In rare cases,a kidney biopsy is necessary to determine the pathological type.

Treatment of Canine Chronic Kidney Disease

Canine chronic kidney disease is a manageable but incurable disease—because by the time a dog shows obvious symptoms,irreversible kidney damage has already occurred.

Clinicians will develop individualized treatment plans based on the stage of the dog's chronic kidney disease.Dogs with stage III or IV chronic kidney disease require more comprehensive care and treatment than those with stage I or II.Common treatments for chronic kidney disease include medication,dietary control,intravenous fluid therapy,and targeted treatment of underlying diseases or triggering factors.

For example,medications such as cimetidine,ondansetron,and omeprazole can be used to relieve symptoms such as nausea,vomiting,and decreased or lost appetite in dogs.In addition,veterinarians may recommend appetite stimulants such as capmorelin and mirtazapine to help dogs regain their appetite.

Most veterinarians will prescribe nutritionally balanced prescription diets for dogs.These prescription diets are typically low in protein,salt,and phosphorus,and are alkaline to help alleviate the side effects associated with chronic kidney disease(CKD).Recommended prescription dog foods include:

-Blue Buffalo Natural Veterinary Prescription Food KS Kidney Support

-Royal Canin Kidney Support Prescription Food

-Hill’s Prescription Food k/d

-Purina Pro Plan Kidney Function Prescription Food NF

Fluid management is crucial for dogs with chronic kidney disease.Infusion therapy helps remove toxins from the blood and improves the dog's hydration.Infusions can be administered intravenously at a veterinary clinic or subcutaneously at home.It is also essential to ensure your dog has access to fresh water at all times—providing a water dispenser at home is particularly important.

Management of Chronic Kidney Disease in Dogs

Chronic kidney disease is a serious,lifelong condition requiring continuous care and monitoring as its symptoms can evolve.Dogs with chronic kidney disease(CKD)require more frequent veterinary checkups than healthy dogs;and their quality of life needs to be assessed based on changes in symptoms at each stage of CKD.

Please strictly follow your veterinarian's follow-up instructions,continuing to administer all recommended medications and adjust the diet as advised—most medications and prescription foods require lifelong use.

Depending on your dog's specific condition,appropriate measures can help maintain its comfort and extend its quality of life as much as possible.Methods and medications similar to those mentioned above are also suitable for the long-term management of chronic kidney disease in dogs,such as:

-Dietary supplements:such as prebiotics/probiotics like Azodyl,which can help reduce metabolic waste that the kidneys cannot excrete.

-Other supplements:such as aluminum hydroxide and epakitin,designed to help lower high phosphorus levels in the dog;or kidney potassium supplements(such as Renal K+),which can help increase potassium levels.

-For dogs experiencing intermittent vomiting and loss of appetite,antiemetics and appetite stimulants may be prescribed as needed.