Kidney disease is a common problem of older dogs, affecting an estimated 10% of canines in their lifetimes1. There are a number of causes that may affect different age groups and have different consequences, ultimately though, chronic kidney disease (occurs over time) or acute kidney injury (occurs suddenly) will always have the same result—one sick pup. The signs of illness in your dog reflect the failure of the kidneys to do their many jobs well enough.
Learn the basics of chronic kidney disease in dogs.
Below you will find a brief description of ten common causes of kidney disease. These are the targets of your veterinarian’s testing:
1. Damage to the kidney filters (glomerular disease)
The glomerulus of the kidney (kidney filtration mechanism) is commonly involved in canine kidney disease. Early on, we expect no signs of illness, but since glomerular disease may be caused by infections (like Lyme disease) or cancer, amongst other things, time can make the problems worse. Over time, inflammation, in the glomerulus of the kidney, damages the surrounding kidney tissues, creating the chronic kidney disease that makes your dog feel sick.
Learn more about glomerular disease in dogs.
2. Infection of kidney tissues (pyelonephritis)
Infection of kidney tissues with bacteria, or rarely, fungal organisms, is one of the kidney diseases that may have a more favorable outcome, so your veterinarian will be on the lookout for it. Our goal with pyelonephritis is to kill the bacteria that can cause the damaging inflammation. This should limit progression of any chronic kidney disease or assist with recovery from an acute kidney injury. A bacterial urine culture and susceptibility can verify the infection and identify which antibiotic might work the best.
3. Kidney stones (nephrolithiasis)
Kidney stones can be the product of chronic bacterial infection, genetics or diseases that alter blood or urine characteristics. Nephro (kidney) liths (stones) don’t seem to cause dogs much pain, but this can change if they cause blockage within the kidney or its collecting ducts; it can also change if they contribute to infection (see pyelonephritis).
Learn more about kidney stones in dogs.
4. Kidney blockage (ureteral obstruction with hydronephrosis)
Kidney stones can fragment and be carried along with urine into the ureter, the long narrow tube that connects each kidney to the urinary bladder. They are probably painful during their transit, but the bigger concern is the consequence to the kidney if they become lodged there, causing partial or complete blockage. New urine cannot exit the kidney easily and it backs up, causing the kidneys to swell. With enough pressure, the kidneys enlarge (hydronephrosis) and become damaged. If both ureters obstruct at the same time, it can prove disastrous.
5. Damage to kidney tubules (tubulointerstitial disease)
Inflammation and damage to the kidney tubules and supporting tissues commonly leads to chronic kidney disease. In many cases there is no identified cause, and thus no option for specific treatment. This type of kidney disease can only be confirmed by microscopic examination of a kidney biopsy specimen, but biopsies are not usually recommended.
6. Bacterial infection (leptospirosis)
Bacterial infection with leptospires causes kidney disease and other organ challenges in dogs and people all over the world. Normally, the effects of leptospirosis will be quite sudden and cause an acute kidney injury. Occasionally, the infection might cause chronic kidney disease. Quick recognition of this highly treatable disease should lead to a better outcome and protect your dog’s friends and family (YOU!) from becoming infected by contact with urine or other body fluids.
Learn more about leptospirosis in dogs.
Lots of household items can damage the kidneys, not just antifreeze. Ordinary table foods like grapes and raisins; certain commercial jerky treat products; common OTC medications like aspirin or other nonsteroidals (NSAIDs); or prescribed medications can all cause kidney disease. Venoms, pesticides and heavy metals are less common toxins. We know dogs like to lick stuff, eat stuff, roll in stuff or bathe in stuff, but that can put them at real risk. To reduce your buddy’s risk of kidney injury, consider limiting his free-roaming behaviors and refrain from giving him any medications without discussing it first with your veterinarian.
See the top 5 most damaging kidney toxins for dogs.
If you have any reason to believe your dog has been poisoned, contact your veterinarian or an emergency veterinarian right away. You may also contact:
- ASPCA Poison Control (888) 426-4435
- Pet Poison Helpline (855) 764-7661
Fortunately, kidney cancer is not very common in dogs. Unfortunately, treatment options for kidney cancer are rather limited. Solitary tumors affecting only one kidney can be removed by surgery with a good outcome, if the cancer is benign or has not spread to other parts of the body (including the opposite kidney). Your dog only needs one good kidney to function normally. If the cancer is more widespread, as usually occurs with lymphosarcoma, surgery will not be an option for cure. Microscopic analysis of a biopsy or small needle sample is needed for the correct diagnosis of cancer and appropriate treatment plans.
Learn 10 signs of cancer in dogs.
9. Protein issue (amyloidosis)
Patients with amyloidosis lose function in certain organs, including the kidneys, because protein deposits replace the normal tissue. It is an uncommon consequence of chronic inflammation affecting other parts of the body. It may also be genetically programmed in some dog breeds. Amyloid deposits cannot be cleared away, and the functional kidney tissue that is lost cannot be replaced, so the prognosis is not good.
Learn more about amyloidosis in dogs.
There are genetic links to various kinds of kidney disease for many purebred dogs. Some young dogs fail to develop normal kidneys, or have kidneys that are large and grape-like, with many fluid- filled cysts. These dogs show signs of kidney disease as youngsters. Other dogs with congenital problems of the glomerulus or with a predisposition to amyloidosis might only show signs or symptoms of kidney disease when they’re adults.
If you have any questions or concerns, you should always visit or call your veterinarian -- they are your best resource to ensure the health and well-being of your pets.
- Brown SA. Renal dysfunction in small animals. The Merck Veterinary Manual website. Updated October 2013. Accessed January 14, 2015.
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