THE 10 MOST COMMON CAUSES OF KIDNEY DISEASE IN CANINES
It has been shown that about 10% of older dogs will develop kidney disease in their lifetime. Chronic kidney disease occurs over time whereas acute kidney disease occurs suddenly and both will end up in a sick dog. The signs of illness in your dog show the effects of the kidneys not doing their many duties well enough.
SAVE YOUR DOG BY KNOWING THE BASICS OF CHRONIC KIDNEY DISEASE
GLOMERULAR DISEASE
Damage to the kidney filtration mechanism (the flomerulus of the kidney) is commonly involved in dog kidney disease. In the beginning, we expect to see no signs of illness, but since glomerular disease may be caused by infections such as Lyme disease or cancer among other things, time here is the enemy and the problem can become worse over a given time. You see over time, inflammation, in the glomerulus of the kidney, damages the surrounding kidney tissues, creating the chronic kidney disease that makes your dog sick.
PYELONEPHRITIS
Pyelonephritis is when the kidney tissues get infected with bacteria, or more rarely, fungal organisms, and is one of the kidney diseases that can have a more favorable outcome, so make sure your veterinarian looks for the signs of it. The 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 the recovery of an acute kidney injury. A bacterial urine culture and susceptibility can verify the infection and identify which antibiotic might work the best.
KIDNEY STONES
Chronic bacterial infection can cause kidney stones to develop as well as, genetics or diseases that alter the blood or urine characteristics. Nephro (kidney) liths (stones) don’t seem to cause dogs to much pain, but this can change if they cause blockage within the kidney or it’s collecting ducts; it can also change if they contribute to infection.
URETERAL OBSTRUCTION WITH HYDRONEPHROSIS
KIDNEY BLOCKAGE
Sometimes kidney stones can break into small fragments and be carried along with urine into the ureter (the long narrow tube that connects each kidney to the urinary bladder). This can be painful during their transit, but the bigger concern is the consequence to the kidney if they become lodged there which can cause partial or complete blockage. New urine cannot exit the kidney easily and it backs up, causing the kidneys to swell. When there’s enough pressure, the kidneys can enlarge (hydornephrosis) and become damaged. If both ureters obstruct at the same time, if can be disastrous.
TUBULOINTERSTITIAL DISEASE
It is important to know that inflammation and damage to the kidney tubules and supporting tissues often 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.
LEPTOSPIROSIS
Bacterial infection with leptospires causes kidney disease and other organ problems in dogs and people worldwide. Normally, the effects of leptospirosis will be quite sudden and cause acute kidney injury. Occasionally, the infectio 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 (which is You) from becoming infected by contact with urine or other body fluids.
TOXINS
There are many items around the home that can damage the kidneys, and not just antifreeze. Foods we take for granted 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. Dogs lick all kinds of things, roll in stuff or bathe in stuff, but all of those things can put them at risk. Try limiting or pay close attention to his daily roaming routines to reduce the risk of him injuring his kidneys and refrain from giving him any medications without discussing it first with your veterinarian.
DOG POISONING
When you have any reason to believe that your dog has been poisoned, contact your veterinarian or an emergency veterinarian immediately. You can also contact:
- ASPCA Poison Control (888) 426-4435 (https://www.aspca.org/petcare/animal-poison-control)
- Pet Poison Helpline (855) 764-7661
CANCER
It is very fortunate that kidney cancer is not very common in dogs. The bad thing is that treatment options for kidney cancer are rather limited. Solitary tumors affecting only one kidney can be removed by surgery with a favorable outcome, if the cancer is benign or has not spread to other parts of the body (including the opposite kidney). Dogs need only one good kidney to function normally. If the cancer is more widespread, as usually happens with lymphosarcoma, surgery will not be an option for a cure. Microscopic analysis of a biopsy or small needle sample is needed for the correct diagnosis of cancer and appropriate treatment plans.
AMYLOIDOSIS
A PROTEIN ISSUE
Dogs 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.
HEREDITARY
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 can show signs of kidney disease as young ones. Other dogs with congenital problems of the glomerulus or with a predisposition to amyloidosis might only snow signs or symptoms of kidney disease when they’re adults.
HOW LONG WILL AN OLD DOG LIVE WITH KIDNEY FAILURE?
The first question you’ll probably have after finding out your dog has kidney failure is how long does he/she have. Like in humans the main cause of death in older dogs is organ failure; however, that doesn’t mean your dog’s time has run out. If kidney failure in dogs is discovered early enough, there are several options for dog owners to slow down the progression of the disease. Sometimes this can translate into a lifespan of many more months, and sometimes, even years.
KIDNEYS WEAR OUT
Old dogs are prone to develop chronic kidney failure due to the simple fact that after years of relentlessly working the kidneys just plain wear out. The fact that the kidneys main purpose is to filter the dog’s blood, removing metabolic waste products from the blood and dumping these toxins out of the dog’s body through the dog’s urine, is why after years of 24/7 they just can’t do it any more.
When the dog’s kidneys stop working as well as they should, toxins start accumulating and the initial reaction of the dog’s body is to cause increased drinking and increased urination, medically known as “polydypsia” and “polyuria.” The purpose of this increase in thirst and urination is an attempt of the dog’s body to flush the bloodstream from the excess toxins.
If this condition progresses the toxins will start building up more and more, and affected dogs may start developing other symptoms. These symptoms include loss of appetite, vomiting, diarrhea, lethargy, ulcers in the dog’s mouth and bad breath.
Urine testing and blood work are used to diagnose kidney failure in old dogs. In dogs with kidney failure, their urine is not as concentrated as it should, therefore a low urine specific gravity and increased protein in the urine can be some of the early signs of problems to come.
Blood work will show abnormal levels of blood urea nitrogen (BUN) and blood creatinine (CREA) and may also show abnormalities in the levels of potassium, phosphorus, and calcium values.
It’s not will known that the age of onset of dog chronic kidney failure varies depending on the dog’s size. Since small dogs tend to live longer, you may only start seeing signs when your small dog is anywhere between 10 to 14 years of age, while in large dogs, kidney failure may pop up as early as seven years of age.
FUNCTIONALITY OF THE KIDNEY
We know that a dog’s life expectancy with kidney failure depends on many factors. The most important factor is maybe how much kidney functionality has been lost. To help determine a dog’s lifespan means that his urine specific gravity and blood has to be looked at.
Another way to assess the situation is through an ultrasound. Ultrasound should be able to indicate whether the kidneys are in the “end-stage” failure and whether there are any tumors. Checking the dog’s blood pressure can be insightful because around 25% of dogs with kidney failure have hypertension. Getting the high blood pressure under control can ultimately help improve the prognosis.
SLOWING THE DISEASE DOWN
The sad thing about kidney tissue is that it cannot be regenerated once it has been destroyed due to chronic kidney failure, but the good news is that a dog’s kidneys are still capable of performing various functions even when they start failing. Most veterinarians say that at least 2/3 of the dog’s kidneys must have become dysfunctional before any advanced symptoms of kidney failure are noticed.
As mentioned before, when caught early enough, the progression of kidney failure in old dogs can be slowed down. So increased drinking and increased urination (especially in older dogs) should be a red flag and reported to the vet immediately. Following are some ways to slow down the progression of kidney failure in dogs.
LOTS OF FLUIDS
Starting with diuresis is one of the best ways to help a dog in kidney failure. Diuresis consists of giving dogs intravenous fluids in order to flush out the accumulated toxins from the bloodstream. In the more serious cases, it may be necessary to schedule three or more days of intravenous diuresis from a hospital setting and see how the dog does by checking the blood work afterward.
These fluids can be given under the skin at home (subcutaneously) after your vet does a demo and the necessary supplies are purchased.
IF YOU NEED MEDICATIONS
Many times affected dogs are put on a prescription diet. Most kidney prescription diets in general have quality protein (but not a lot of protein) and are low in phosphorus and sodium so to lower the production of metabolic toxins and diminish the workload on the kidneys. The addition of omega-3 fatty acids (fish oil) to diets has also been shown to be beneficial. Common kidney diets for dogs include Hill’s K/D, Purina NF and Royal Canin Renal Support.
REMEMBER
Kidneys in general use a small percentage of their capacity at any one point in time. They have a lot of reserve function. Because of this reserve, clinical evidence of renal failure does not become apparent until about 80% of the functional units are lost. To be save it would be advisable to start having blood tests and ultrasound more often than not once your dog reaches middle age.
