How do my dog’s kidneys work?
Properly functioning kidneys work to continually remove toxins from your dog’s body. The kidneys also help to release hormones required to produce red blood cells, conserve water, regulate levels of specific minerals such as sodium and potassium, and maintain a normal electrolyte balance.
What is chronic kidney failure in dogs?
Kidney failure is commonly referred to as renal failure and chronic kidney disease and means that your pet’s kidneys are not able to efficiently filter waste products from the blood. While most dogs suffering from kidney failure produce large quantities of urine, toxic wastes are not being effectively eliminated from the body.
In many cases, destruction of kidney tissue has been occurring for months to years before signs of failure appear. This tissue does not regenerate when destroyed, so the kidneys naturally have a large reserve capacity to perform the functions described above. At least two-thirds of the kidneys must be dysfunctional before any clinical signs will be seen.
Chronic kidney disease and failure in dogs is related to aging, and often occurs when the kidney tissues have ‘worn out’. The age many dogs start to experience this condition is often related to their size. For most small dogs, early signs happen between 10 and 14 years of age. However, since larger dogs have a shorter life span their kidneys may fail as early as seven years of age.
What are the signs of chronic kidney failure in dogs?
Dogs’ kidneys perform many functions, so symptoms of chronic kidney failure can vary quite a lot. Symptoms may be subtle or severe, and they can appear suddenly — despite the chronic nature of the disease.
Some more common symptoms of chronic kidney failure in dogs include:
- Weight loss and lack of appetite
- General depression related to more waste products in the blood
- Drinking too much and urinating large volumes or urine
- Incontinence due to increase volume of urine in the bladder
- Overall weakness from low blood potassium
- Diarrhea or vomiting
- Anemia, leading to weakness and pale gums due to low blood count
Less common signs include:
- Bleeding into the gut or stomach
- Skin bruising
- Bone fractures caused by weakened bones
- Itchy skin from phosphorous and calcium deposits on the skin
- High blood pressure, leading to sudden blindness
You may notice ulcers in the mouth, dehydration, weight loss and pale gums. Since many symptoms are not specific to chronic kidney failure, your vet will need to test your dog’s blood and urine to officially diagnose the condition.
What are stages of chronic kidney failure in dogs?
Your vet will be able to estimate the severity of kidney failure or disease based on blood waste product elevation and urine abnormalities such as the presence of protein.
A method to estimate the four stages of chronic kidney disease has been developed by the Internal Renal Interest Society (IRIS). Stage 1 is the least severe and 4 is the most severe. The higher the stage number, the more likely you are to see a higher number of symptoms. Some treatments are only recommended when the pet has reached a certain stage.
How is chronic kidney failure diagnosed?
Other than blood and urine tests, your vet may also take X-Rays and do a biopsy to evaluate the size of the kidneys, or to identify the cause or diagnose chronic kidney failure.
The vet may also take a bacterial culture, as many pets with chronic kidney failure also have bacterial infections since their immune system may be less functional. If your dog does need a biopsy, tests may be performed prior to the procedure to assess the ability to stop bleeding from the biopsy site.
What treatments can my vet offer for chronic kidney failure in dogs?
Chronic kidney failure or disease cannot be cured. Your veterinarian can determine which treatments are needed based on the severity of your dog’s symptoms, as not all treatments may be required or appropriate.
If your dog is still eating and not displaying severe signs, the vet may take a conservative approach to treatment. Treatments are designed to reduce the buildup of wastes, replace certain substances that may be too low and to reduce the work kidneys need to perform.
It may take weeks or months to see a response. The vet may also recommend a special diet, medications and antibiotics to reduce stress on your pet’s system, treat infections, improve quality of life and potentially minimize the disease’s progression, resulting in a longer lifespan.
To treat anemia, your dog may need a blood transfusion, or the vet may administer human erythropoietin to increase packed cell volume — the percentage of blood cells compared to fluid in whole blood.
If severe signs of kidney failure are detected, hospitalization may be necessary so your dog can receive IV drugs and fluids. Though many pets may feel better, if the disease is extremely severe your pet may not respond to treatment.
What are common treatment outcomes and life expectancy estimates?
The first phase of treatment may result in one of three potential outcomes:
- The kidneys resume functioning and continue to function for a few weeks or a few years.
- The kidneys resume functioning during treatment, but fail as soon as treatment stops, typically within 3 to 14 days.
- Kidney function will not return.
Like many other factors when it comes to chronic kidney disease, prognosis will vary depending on your dog’s response to the initial stage of treatment and your ability to maintain follow-up care. In most situations, vets encourage treatment as many dogs respond well and are able to maintain a good quality of life.
Our vets at Westport Veterinary Associates have years of experience in providing quality geriatric care for senior dogs and cats. We can carefully examine your pet, diagnose any health issues such as kidney failure or disease, develop an action and treatment plan, and provide treatment and follow-up care. We also practice internal medicine to treat disorders and diseases affecting multiple internal organs.
Note: The advice provided in this post is intended for informational purposes and does not constitute medical advice regarding pets. For an accurate diagnosis of your pet's condition, please make an appointment with your vet.