Kidney Enlargement in Dogs

Kidneys are essential to your dog’s health because they remove the toxins and wastes from his body through urine. If one of both of your dog’s kidneys are enlarged, a serious problem needs attention by your veterinarian right away. The cause of enlarged kidneys can be many different things and the main objective is to determine the cause and fix that problem before too much kidney damage is done. Your veterinarian can give your dog a physical examination and perform tests to find the cause right away. It could be as simple as a kidney infection or as serious as cancer. The sooner the cause is found, the better the potential outcome will be for your dog.

Kidney enlargement in dogs, also referred to as canine renal enlargement, is the swelling of one or both of the dog’s kidneys. The length of a dog’s kidneys is approximately three times the size of the second lumbar vertebrae. Many things, including but not limited to, cysts, abscess, neoplasia, hematoma, hydronephrosis, edema, and injury, can cause kidney enlargement.

• Extreme thirst
• Increased body temperature
• Back or belly pain
• Increased urination
• Bad breath odor
• Mouth sores
• Nausea
• Vomiting
• Weakness
• Stiff walking
• Appetite loss
• Weak or rapid pulse
• Vision problems
• Dark urine
• Dizziness
• Staggering
• Convulsions
• Coma

 Types

Acute kidney enlargement often comes on suddenly and is usually caused by trauma or serious illness. This type is easier to recognize and determine the cause.

Chronic kidney enlargement is a gradual disease that comes on slowly and is hard to recognize. Usually by the time the symptoms get bad enough for you to notice them there is already substantial damage done to the kidneys.

Acute Kidney Enlargement

• Infection
• Injury
• Toxins
• Kidney stones
• Acute renal failure
• Urinary obstruction

 Chronic Kidney Enlargement

• Certain breeds of dogs are predisposed to kidney disease, such as Beagle, Terrier, Chow, Cocker Spaniel, Bernese Mountain Dog, Doberman, Lhasa Apso, Retriever, Schnauzer, Corgi, Shar-Pei, Rottweiler, Samoyed, Newfoundland, Shih Tzu, Malamute, and Poodle
• Old age
• Previous history of renal diseases
• Chronic kidney infection
• Lymphoma
• Tumor

The first thing your veterinarian will do is talk to you about your dog’s medical history and recent symptoms. The veterinarian will then do a complete thorough examination of your dog’s entire body, concentrating on your dog’s abdomen (palpation), heart rate, blood pressure, and mucous membranes. Some tests that are essential for diagnosis are:

• Complete Blood Count (CBC)
• Chemical panel (urea, creatinine, nitrogen)
• Blood gas
• Urinalysis (protein, sediment, specific gravity)
• Fungal culture
• Bacterial culture
• Electrolyte panel
• Radiographs (x-rays)

Your veterinarian may also need to do further testing if he suspects other problems:

• Ultrasound (kidney shape, size, and density)
• Biopsy
• CT scan
• MRI
• IV pyelogram (dye imaging)

 Depending on the results of these tests, your veterinarian may decide to do more tests to determine the extent of the damage in your dog’s kidneys.

The treatment depends on the type and cause of the kidney enlargement in your dog.

 Acute Kidney Enlargement

Infection

Your dog may need to stay overnight in the hospital to get IV fluids and antibiotics. If your dog’s kidneys seem to be handling the fluids well and he is able to urinate, he may be sent home with oral antibiotics.

 Injury

Your dog will need to stay overnight in the hospital to get IV fluids and antibiotics.

If the injury is mild or moderate and can heal on its own, your dog will be sent home as soon as the swelling goes down and he is able to urinate on his own. Your veterinarian may prescribe pain medicine or steroids to control swelling.

 Toxins

Your veterinarian may perform a gastric lavage to empty your dog’s stomach and give him charcoal to absorb the toxins, depending on the timing. Your dog will also get IV fluids and possible an antitoxin or antibiotic. Once he is stable, your veterinarian will send you home with strict instructions to come back immediately if your dog starts having symptoms of relapse.

 Kidney stones

Your veterinarian will have to find out whether the stones are triple phosphate (struvite), urate, or calcium stones. A special diet of low protein, magnesium, and phosphorus is sometimes used to dissolve struvite stones. If the stones are still not dissolved, the veterinarian will remove them surgically. Urate stones need diets low in purines and protein as well as a drug (allopurinol) to dissolve the stones. Calcium stones and any other stones that do not dissolve quickly through diet or medication need to be removed with surgery. The veterinarian might need to perform surgery right away if your dog is in intense pain or if the stones are too large to dissolve quickly.

 Chronic Kidney Enlargement

Hereditary

Hereditary kidney disease that causes chronic kidney enlargement is usually treated with palliative care and management. There is no treatment to get rid of a hereditary kidney disease so the best that can be done is to treat the symptoms as they arise. A special diet is also usually prescribed to help reduce inflammation and infection.

 Age

Kidney enlargement caused by old age is treated with IV fluids to relieve the inflammation and reset the kidneys to get them to work again. This is a temporary solution and your dog will need to see the veterinarian often to evaluate the kidney function and prescribe medication or a diet that can help relieve symptoms as they arise.

 Tumor

IV fluid therapy to stabilize your dog’s electrolytes will be done in the office while the biopsy and other tests are being done. Tumors of the kidney are not common in dogs, but when they occur, they are usually malignant (cancerous). The only way to treat this is with surgery to remove the tumor(s) and chemotherapy. However, these treatments do not usually work well and prognosis is not good.

Acute kidney enlargement has a fair prognosis with proper treatment and follow-up examination.

 Chronic kidney enlargement prognosis depends on the diagnosis, but since this disorder is not usually noticed until significant damage is done, the prognosis is not generally good. Sometimes, a cancerous tumor can be removed surgery, and your dog can live for several more good years with an aggressive chemotherapy treatment.

 The most important part of your dog’s recovery and management is to feed him a healthy diet, provide plenty of exercise, and regular veterinarian visits.