What Is Chronic Renal Failure in Dogs?
Chronic renal failure (CRF), renal insufficiency, and chronic kidney disease (CKD) all refer to the same medical condition, which arises when the kidneys lose their ability to function efficiently. In dogs, these two vital organs are situated on either side of the abdomen, playing a crucial role in filtering waste from the body. Moreover, they regulate fluid, mineral, and electrolyte balance, conserve water and protein, and produce erythropoietin, a hormone essential for maintaining blood pressure and red blood cell levels.
The survival of dogs hinges on the health of their kidneys, as kidney transplants remain an unviable solution and dialysis—a treatment involving waste removal—is exceedingly rare and expensive for canines. Nonetheless, early detection and intervention are imperative to uphold a dog’s quality of life.
Upon diagnosis, CRF is categorized into four stages based on the severity of clinical signs and laboratory findings:
- Stage I: Clinical signs are typically not evident.
- Stage II: Some clinical signs become noticeable.
- Stage III: Many clinical signs manifest, and pets often exhibit feelings of illness.
- Stage IV: The majority of clinical signs become apparent, and pets may present in a crisis state.
Symptoms
The symptoms of chronic renal failure (CRF) in dogs typically correspond to the stage of severity, with more pronounced and severe signs observed in stages III and IV compared to stages I and II. Common symptoms exhibited by dogs include:
- Increased thirst and urination
- Occasional vomiting
- Dehydration
- Oral ulcerations (mouth sores)
- Foul breath
- Weight loss
- Reduced appetite
In some cases, dogs may also display muscle wasting and symptoms associated with high blood pressure, such as vision impairment and weakness.
Causes
Chronic renal failure in dogs is characterized by its progressive nature, with the term “chronic” indicating that the condition cannot be reversed once it has begun. The causes of this condition vary among individual dogs.
In some cases, chronic renal failure may develop following a significant kidney injury, such as from a severe infection like leptospirosis or pyelonephritis, or ingestion of toxic substances such as anti-freeze, grapes, raisins, and certain antibiotics.
In other instances, the condition may be inherited, as is the case with glomerular disease, a specific type of renal kidney disease, and amyloidosis, a rare organ disease observed in breeds like the Bernese Mountain Dog and Shar-pei.
Additionally, chronic renal failure may be linked to underlying immune-mediated diseases, stroke-like events, or clotting disorders. However, for newly diagnosed dogs, identifying the underlying cause may prove challenging and often remains unknown.
Diagnosis
Veterinarians typically diagnose chronic renal failure (CRF) in dogs through a series of diagnostic tests that examine various markers associated with kidney function. These tests include:
- Blood urea nitrogen (BUN): Elevated levels of BUN, a by-product of protein metabolism, often indicate kidney failure.
- Creatinine (CREA): This measures the kidneys’ ability to filter waste from the blood.
- Phosphorus: Elevated phosphorus levels are indicative of kidney damage.
- Electrolytes (Sodium, potassium, chloride)
- Calcium
- Red blood cell count: A decreased count may signal kidney failure.
- Symmetric dimethylarginine (SDMA): This test aids in early detection of kidney disease.
- Urine specific gravity: This indicates the concentration or dilution of urine, with higher values suggesting better kidney function in conserving water.
In addition to these blood and urine tests, veterinarians may recommend further diagnostic evaluations such as:
- Urine protein to creatinine (UPC) ratio to quantify protein loss in urine.
- Urine culture to detect urinary tract infections, which are more common in dogs with chronic kidney disease (CKD).
- Blood pressure assessment.
- Radiographs or abdominal ultrasound to identify kidney stones or areas of dead tissue (infarcts).
These diagnostic procedures help veterinarians gain a comprehensive understanding of the dog’s kidney health and determine the appropriate course of treatment.
Treatment
Treating chronic renal failure (CRF) in dogs presents challenges, especially considering that affected dogs are typically older and may have concurrent health issues like arthritis or liver disease. Nonetheless, CRF can be effectively managed through a combination of medications, dietary adjustments, and hydration strategies.
Treatment approaches are tailored to the specific stage of CRF, with recommendations evolving as the disease progresses. Dogs showing an increase in urine protein to creatinine ratio (UPC) or high blood pressure at any stage are likely to receive medication.
Maintaining hydration is crucial throughout the dog’s life, especially during periods of illness or other conditions that may impact hydration levels. Prompt treatment with intravenous fluids is recommended for any disease or illness affecting hydration status.
Prescribed medications should be carefully selected, considering the altered renal metabolism in dogs with CRF to prevent overdoses or worsening of kidney function.
Furthermore, ensuring access to fresh water at all times and encouraging adequate fluid intake is essential. Dogs diagnosed with CRF often benefit from a kidney-friendly diet, which may involve feeding wet food containing additional water to help maintain hydration levels.
Living and Management
Since chronic renal failure (CRF) is neither curable nor predictable in its progression, early diagnosis is crucial for implementing effective management strategies. Dogs diagnosed with CRF benefit from ongoing veterinary care and nutritional management, which may entail more frequent check-ups and monitoring of blood parameters. For dogs in stages I and II, close monitoring for any progression of symptoms is essential. Some may be prescribed a specific diet aimed at easing the workload on the kidneys.
Many dogs diagnosed early can maintain a satisfactory quality of life for months to years. However, those in stages III and IV typically require more intensive medical and dietary support. If secondary anemia is present, veterinarians may administer erythropoietin injections.
Supplements, phosphorus binders to address elevated phosphorus levels, and potassium supplements may be prescribed as needed. Anti-nausea and anti-emetic medications can alleviate symptoms like poor appetite, vomiting, or nausea. Dehydration can be managed with intravenous or subcutaneous fluid therapy.
Due to the severity of symptoms in dogs with advanced stages of CRF and the significant care they require, some may undergo humane euthanasia to alleviate suffering and maintain their quality of life.
Chronic Renal Failure (CRF) In Dogs FAQs
What is the life expectancy of a dog with kidney failure without treatment?
Without treatment, dogs suffering from kidney failure typically succumb within a few days to a few weeks. This is often preceded by symptoms like loss of appetite, dehydration, weight loss, vomiting, and eventual multi-organ failure.
Is it possible for dogs to recover from chronic renal failure?
There is no known cure for CRF. However, if CRF is detected early and managed effectively, most dogs with kidney disease can enjoy a relatively normal life with appropriate adjustments and ongoing management.
Can chronic renal failure in dogs be reversed?
CRF cannot be reversed. Nevertheless, prompt treatment upon diagnosis can significantly enhance your pet’s quality of life, leading to a happier and longer existence. Regular semi-annual veterinary checkups are essential for the early detection and management of chronic renal disease.