Kidney Disease in Dogs: Causes and Treatments

Kidney disease in dogs is a set of conditions affecting the renal structure and function. The two main types of kidney disease are acute and chronic. 

Common causes of kidney disease in dogs are genetics, infections, urinary stones, toxins, some medications, envenomation, auto-immune conditions, heat stroke, and cancer. 

Early signs of kidney disease, like slight weight loss, vomiting or diarrhea, increased thirst, and frequent urination, are easily missed. Advanced kidney disease causes anemia, mouth ulcers, and brittle bones. 

Kidney issues in dogs manifest when the kidneys lose 75% of their function and the condition becomes advanced. Kidney disease is classified into four stages, with stage one being the least severe and stage four indicating kidney failure in dogs. 

Vets perform various blood and urine tests combined with diagnostic imaging to determine how do dogs get kidney disease. The treatment depends on the stage and includes fluids, meds, or aggressive techniques like dialysis and renal transplantation. 

Chronic kidney disease in dogs is incurable. The goal is to maintain the dog’s quality of life for as long as possible. 

What is kidney disease in dogs?

Kidney disease in dogs is an umbrella term that includes kidney problems that prevent normal function. Untreated renal disease progresses to failure or complete cessation of function. 

Renal problems in dogs are widespread. “1 in 10 dogs suffer from kidney disease,” reports Dr. Celeste Clements in an article “Kidney Disease in Dogs: What Dog Owners Should Know” for PetHealthNetwork.  

Kidney disease in dogs is categorized as acute or chronic. Acute kidney disease is associated with toxins, and chronic kidney disease (CKD) is prevalent in older dogs. 

CKD is a problem with the kidneys that lasts for over three months. Chronic kidney disease is sinister because many dogs remain asymptomatic in the early stages. 

Signs of illness become apparent when the kidneys lose up to 75% of their function. Early diagnosis is essential for a positive outcome. 

What are the main functions of the kidneys in dogs?

The main functions of the kidneys in dogs are waste removal, water level balancing, blood pressure regulation, and red blood cell regulation. 

Waste removal refers to the kidneys filtering out toxins, metabolism waste products, and excess fluids from the body. Toxins and waste products are life-threatening if not eliminated. 

Water level balancing maintains equilibrium by keeping fluids in the body when water intake is low and expelling water when the intake is high. 

Blood pressure regulation occurs since the kidneys produce a blood vessel-constricting protein. The protein informs the body on necessary pressure changes because the kidneys need certain pressure to filter blood efficiently. 

Red blood cell regulation is achieved by synthesizing a hormone called erythropoietin. The hormone stimulates the production of red blood cells because the kidneys need oxygen to work correctly.   

What are the types of kidney disease in dogs?

The two main types of kidney disease in dogs are acute and chronic. Acute kidney disease occurs when the kidneys suffer from toxin exposure, infectious agents, bladder stones, or lack of oxygen supply. 

Chronic kidney disease (CKD) develops slowly and over a distended timeframe. CKD develops when the central functional renal units, called nephrons, become damaged and lose function. 

The chronic form of kidney disease is standard for seniors, but it is visible in younger dogs with hereditary renal problems. CKD is sometimes a consequence of untreated acute kidney disease. 

What Are the Different Stages of Chronic Kidney Disease In Dogs?

The different stages of chronic kidney disease in dogs are listed below. 

• Stage I: Dogs do not exhibit clinical signs of illness, but their kidneys appear abnormal on exam and ultrasound. The urine is diluted and contains high amounts of protein. Creatinine levels are normal, and there is no azotemia.  
• Stage II: Dogs develop mild signs of disease, like a slight appetite decrease and weight loss. Creatinine levels are normal or mildly elevated, and the dog has mild azotemia. Stage II is the turning point from the early stages of kidney disease in dogs to the late stages. 
• Stage III: Dogs show moderate and highly variable signs of disease, including hair loss, intermittent appetite changes, vomiting, diarrhea, and lethargy. Azotemia and increased SDMA levels are visible at this stage.     
• Stage IV: Dogs manifest severe signs of disease and kidney failure and have marked azotemia. The goal for kidney disease in dogs stages at IV is to maintain life quality and to keep the dog comfortable. 

What causes Kidney Disease in dogs?

The causes of kidney disease in dogs are listed below. 

• Genetics: Various kidney diseases in dogs have a hereditary or genetic component and occur in particular dog breeds. Certain problems linked to the kidneys’ development manifest at a young age, and others do not trigger symptoms until later in life. 
• Infections: Lyme disease and leptospirosis attack dogs' kidneys. Infections travel to the kidneys from distant sources, like tooth abscesses. Giant kidney worms in dogs are capable of causing infections. 
• Urinary Stones: Kidney and urethral stones cause blockages, which increase the risk of kidney infections and retain water in the kidneys (hydronephrosis), resulting in tissue damage and loss of function. 
• Toxin Exposure: Ingestion of certain chemicals (antifreeze or ethylene glycol), foods (grapes and raisins), and human medications (ibuprofen) cause acute kidney damage or failure in dogs. 
• Certain Medications: Specific medications have a nephrotoxic effect and damage the kidneys. Examples are non-steroid anti-inflammatory drugs (NSAIDs), certain antibiotics (aminoglycosides, sulfonamides, and polymyxins), antifungals (amphotericin), and some chemotherapeutics.  
• Envenomation: Some dogs develop kidney disease after being envenomated by bites and stings from venomous snakes, spiders, and insects. 
• Auto-Immune Conditions: Glomerulonephritis in some dogs develops when immune complexes (which bind antigens and antibodies) become trapped in the glomeruli instead of being eliminated. The immune system responds by attacking the complexes and damaging the kidneys. 
• Heat Stroke: Heat stroke is the cause of kidney failure in dogs in severe cases. Brachycephalic dog breeds that are unable to be ventilated properly are particularly sensitive to hot temperatures and are at high risk of heat stroke. 
• Cancer: The answer to “what causes kidney disease in dogs” in certain situations is cancer. Primary tumors of the kidneys are rare in dogs, but metastatic tumors are more likely and include renal carcinoma and cystadenocarcinoma.  

Are certain breeds more susceptible to kidney disease?

Yes, certain breeds are more susceptible to kidney disease. Familial renal disease is prevalent in Cairn Terriers, Chow Chows, Boxers, Shih Tzus, Golden Retrievers, Lhasa Apsos, Standard Poodles, Dobermans, and Beagles. 

Primary glomerulonephritis occurs in Bernese Mountain Dogs, Dalmatians, Rottweilers, Cocker Spaniels, English Springer Spaniels, Bull Terriers, Corgis, and Basenjis. Amyloidosis occurs in English Foxhounds, Shar Peis, Beagles, and Bulldogs. 

Polycystic kidney disease is widespread among Cairn Terriers, Bull Terriers, and West Highland Terriers. Immune-mediated glomerulonephritis develops in Brittany Spaniels, Bernese Mountain Dogs, and Soft-Coated Wheaten Terriers. 

Multifocal cystadenocarcinoma is standard for German Shepherds, telangiectasia for Pembroke Welsh Corgis, and Fanconi syndrome in Basenjis and Labrador Retrievers. 

What dog ages are more likely to develop kidney disease?

Dogs are more likely to develop kidney disease after the age of seven. Older dogs are prone to kidney disease and other age-related conditions that increase the risk of renal problems. 

Increasing age is a significant risk factor for CKD in dogs, according to a study, “Chronic Kidney Disease in Dogs in UK Veterinary Practices: Prevalence, Risk Factors, and Survival,” published in the Journal of Veterinary Internal Medicine in 2013. 

The only exception is juvenile-onset chronic kidney disease (JOCKD) or juvenile nephropathy (JN), which is a consequence of familial renal disease and occurs in puppies under two years. 

What are the early signs of kidney disease in dogs?

The early signs of kidney disease in dogs are listed below. 

• Vomiting and Diarrhea: Intermittent vomiting and diarrhea are seen in some dogs with kidney disease, with the symptoms being non-specific and often overlooked. 
• Subtle Weight Loss: Subtle weight loss is one of dogs' earliest signs of kidney disease. The dog’s appetite is slightly altered, reducing body weight. 
• Increased Thirst: Dogs in the early stages of kidney disease exhibit increased thirst and water intake, called polydipsia. 
• Increased Urination: Excessive urination is one of the telltale kidney disease in dogs symptoms, but it is difficult to notice, especially in indoor-outdoor dogs. The medical term for increased urine volume is polyuria, and increased urination frequency is pollakiuria. 

What are the visible signs of advanced kidney disease in dogs?

Visible signs of advanced kidney disease in dogs are nausea, appetite loss, house soiling, pale gums, mouth ulcers, poor coat quality, and fragile bones. 

Dogs with kidney disease are nauseated and reluctant to eat. House soiling results from high volumes of diluted urine, which the dog is unable to hold. 

Pale gums are caused by inadequate erythropoietin production and anemia, and mouth ulcers occur due to the buildup of toxins in the dog’s body. 

Anorexia and waste accumulation lower coat quality. Excess phosphorus in the blood pulls calcium from the bones, making them fragile. 

Can kidney disease cause pain in dogs?

Yes, kidney disease can cause pain in dogs. Renal conditions cause abdominal pain, ranging from mild to severe, depending on the type. 

Renal failure is more painful because it causes a buildup of toxins in the dog’s body. The presence of the toxin makes the dog uncomfortable or painful. 

A side effect of excess toxins in the body is the formation of excruciating sores in the mouth. 

How does kidney disease in dogs increase the risk of urinary tract infections (UTIs)?

Kidney disease in dogs increases the risk of urinary tract infections by lowering immunity, affecting urine concentration and pH, and reducing the filtering capacity. 

Dogs with kidney disease have weakened defenses against infections, including those of the urinary tract. Diseased kidneys produce diluted urine that is not acidic enough, hence creating a perfect environment for bacteria overgrowth. 

The kidneys are unable to filter blood and bodily fluids properly, allowing germs to accumulate and causing urinary tract infections (UTIs).

How is kidney disease diagnosed in dogs?

Kidney disease is diagnosed in dogs through clinical examination and by measuring specific blood and urine parameters. A critical parameter is symmetric dimethylarginine (SDMA). 

SDMA increases when the kidneys are damaged by as little as 25%, reports a study, “Serum Concentrations of Symmetric Dimethylarginine and Creatinine in Dogs with Naturally Occurring Chronic Kidney Disease,” published in the Journal of Veterinary Internal Medicine in 2016. 

Creatinine, once considered the golden standard for diagnosing kidney disease in dogs, requires up to 75% kidney tissue damage to manifest. 

Other assessed values are blood urea nitrogen (BUN), creatinine (CREA), electrolytes, calcium, phosphorus, red blood cell count, urine protein to creatinine ratio (UPC), and urine specific gravity. 

A urine culture is recommended for urinary tract infections, and an abdominal X-ray or ultrasound to look for infarcts, stones, or tumors. 

What are the common treatments for kidney disease in dogs?

Common treatments for kidney disease in dogs are fluid therapy and drugs that help remove phosphorus, lower blood pressure, and manage the symptoms. 

A special diet formula is prescribed to support kidney function. Dogs with acute KD are treated on an outpatient basis. 

The goal of the treatment for dogs with chronic kidney disease is to inhibit the condition’s progression and keep the dog comfortable. CKD is incurable, and the damage to the kidneys is irreversible, but it is manageable. 

The treatment for kidney failure in dogs is aggressive and entails dialysis or kidney transplants. Dialysis and kidney transplantation are challenging and cost-prohibitive in dogs. 

What medications are typically used to treat kidney disease in dogs?

Medications typically used to treat kidney disease in dogs are phosphate binders, anti-blood pressure meds, anti-nausea and vomiting drugs, and appetite stimulants. 

Phosphate binders help remove excess phosphorus from the body, which is removed through the kidneys. Examples of phosphate binders are aluminum hydroxide, lanthanum, and calcium carbonate with chitosan.

Anti-blood pressure medications, such as benazepril and enalapril, lower the blood pressure in the kidneys, decreasing proteinuria.

Anti-nausea and vomiting medications, such as maropitant and omeprazole, manage the two symptoms of kidney disease, and appetite stimulants like capromorelin and mirtazapine support a healthy food intake. 

Can kidney disease in dogs be treated with surgery?

Yes, kidney disease in dogs can be treated with surgery. Kidney transplantation is an option in some situations, but it is rarely performed. 

The survival rates for dogs with kidney transplants are meager, and the procedure is complex, inhibiting routine use. A small number of veterinary centers offer kidney transplantation for dogs.

Donor dogs are screened for diseases. Recipients with advanced kidney disease must receive daily dialysis to return to the early stages and increase the chance of accepting the new kidney before the surgery. 

What are the best probiotics for dogs with kidney disease?

The best probiotics for dogs with kidney disease are Vetoquinol Azodine, Honest Paws Well Pre + Probiotics, and The Honest Kitchen Instant Goat's Milk with Probiotics. 

Probiotics slow the progression of renal deterioration. Dogs supplemented with probiotics have higher glomerular filtration rates (GFR), indicating better kidney function. 

“Dietary probiotics can be a potential alternative therapeutic agent for management of renal failure,” says a study “Probiotic Dietary Supplementation in a Dog with Chronic Kidney Disease,” published in the Journal of Biomedical and Translational Research in 2014. 

• Vetoquinol Azodine: Azodine is formulated to support kidney health in dogs with kidney disease. It helps improve BUN and CREA in four weeks. Each capsule has 15 billion CFUs and is small for easy use.    
• Honest Paws Well Pre + Probiotics: Well Pre + Probiotics is a wellness formula in chicken or pumpkin-flavored powder form. The supplement features six different strains of bacteria and dietary fiber. The fiber helps eliminate protein digestion waste products.
• The Honest Kitchen Instant Goat's Milk with Probiotics: Honest Kitchen’s Goat Milk with Probiotics is one of the best probiotics for dogs with kidney disease. Goat milk is recommended for kidney problems, and the beneficial bacteria support the gut. 

Can kidney disease in dogs be prevented?

Yes, kidney disease in dogs can be prevented. Helpful tips are providing a healthy diet, ensuring access to drinking water, maintaining dental hygiene, and practicing regular vet checkups. 

• Healthy Diet: Provide a healthy and nutritionally balanced food fit for the dog’s breed, age, and lifestyle. Consult the vet if the dog is at high risk for kidney disease to select the best food option.  
• Fresh Drinking Water: Ensure the dog has constant access to fresh drinking water to support hydration. Consider using water fountains or add a few drops of tuna juice or low-sodium chicken or beef broth to the drinking water. 
• Dental Hygiene: Maintain optimal dental hygiene to minimize the risk of dental problems that lead to kidney disease. Brush the dog’s teeth at least thrice weekly and use dental sticks or pet-friendly mouthwashes. 
• Veterinary Checkups: Visit the veterinarian regularly for routine checkups. Exams are the perfect opportunity to catch health issues early and prevent them from progressing into more severe conditions. 

How can you boost a dog's immune system to help prevent kidney disease?

Boost a dog’s immune system to help prevent kidney disease by following the four steps listed below. 

1. Give CBD oil. Supplement the dog with CBD oil. Cannabidiol (CBD) is a natural hemp extract that modulates the dog’s immune system. CBD has strong anti-inflammatory and anti-pain properties that benefit dogs with kidney disease. 
2. Try probiotics. Probiotics promote a healthy gut microbiome, which directly affects immunity because a significant part of the immune system is in the gut. 
3. Add prebiotics. Prebiotics are dietary fibers that serve as food sources for probiotics, affecting immunity indirectly. Dietary fiber helps the dog’s body remove protein waste products, decreasing the kidneys' workload. 
4. Use omega fatty acids. Omega fatty acids have potent anti-inflammatory effects and support the dog’s immune system. Omegas are recommended for dogs with kidney disease. 

What diet is recommended to prevent kidney disease?

The diet recommended to prevent kidney disease in dogs contains potassium and is low in phosphorus. 

Low-potassium and high-phosphorus foods are associated with an increased risk of kidney disease in cats, and the same is believed to be true for dogs. 

Dogs diagnosed with chronic kidney disease benefit from food formulas with reduced protein, sodium, and phosphorus and higher amounts of potassium and omega-3 fatty acids. 

The food must be palatable because dogs with CKD exhibit reduced appetites. Recommended dietary supplements include omega fatty acids, antioxidants, probiotics, and prebiotics.