Your dog’s kidneys are essential organs that filter waste products from the bloodstream. When the kidneys are weakened, either by acute or chronic kidney disease, your dog’s health could suffer. Because kidney disease progresses over time, it’s important to learn the common symptoms so tha you can recognize them. If you catch kidney disease in dogs early on, treatment can slow down the progression and allow your dog to live longer.
What Is Kidney Disease in Dogs?
Kidney disease in dogs is sometimes called renal or kidney insufficiency because it occurs when a dog’s kidneys stop doing their job as efficiently as they should. “The main job of the kidneys is to help clear and excrete waste products from the blood and convert them to urine,” says Dr. Jerry Klein, Chief Veterinary Officer for the AKC. “If the kidneys are not working properly, these waste products can build up in the blood, causing detrimental effects.”
Dogs can get either acute kidney disease, which develops suddenly, or chronic kidney disease (CKD), which develops slowly and worsens over an extended period. Both involve loss of kidney function, but they result from different circumstances. “Acute kidney disease is a sudden attack or injury to the kidney, whereas chronic kidney disease is a slow, degenerative loss of kidney function,” Dr. Klein explains.
What Causes Kidney Disease in Dogs?
Dr. Klein warns that kidney disease could be caused by a lot of things, including infection (such as with the bacteria that causes leptospirosis), trauma, genetics, drugs, toxins, cancer, mechanical obstructions (like kidney stones), and degenerative diseases (where the job and form of the affected body part get worse over time). Anything that decreases blood flow to the kidneys, such as dehydration or heatstroke, can cause the kidneys to fail.
Acute kidney disease in dogs can be caused by exposure to hazardous materials, including toxic plants such as lilies, certain drugs, harmful foods such as grapes or raisins, or antifreeze. Puppy-proofing your home and yard can keep your dog away from potentially harmful items or foods that could be toxic.
Chronic kidney disease in dogs is also associated with growing older. Because kidney tissue can’t regenerate once it’s damaged, the kidneys can wear out over time. As small-breed dogs often live longer than large-breed dogs, they tend to show early signs of kidney disease at an older age—10 years old or more, compared to as young as 7 for the large breeds.
What Are the Symptoms of Kidney Disease in Dogs?
The earliest signs of kidney disease in dogs are increased urination and therefore increased thirst. Other symptoms don’t usually become apparent until about two-thirds of the kidney tissue is destroyed. So, in the case of CKD, the damage may have begun months or even years before the owner notices. Because of this, it’s common for the signs of kidney disease in dogs to seem like they came out of the blue when in fact, the kidneys have been struggling for a long time.
Other signs of chronic kidney disease in dogs to watch for include:
- Weight loss
- Loss of appetite and/or nausea
- Blood in the urine
- Protein in the urine (your vet will run a urinalysis test to see if this is the case)
- Bad breath
Dr. Klein says there are some rarer symptoms of kidney disease in dogs to be aware of, as well. “On occasion, there can be abdominal pain—urinary obstructions or stones—and in certain instances, one can see ulcers in the oral or gastric cavity. In extreme cases, little or no urine is produced at all.”
What Are the Stages of Chronic Kidney Disease in Dogs?
Kidney disease in dogs is measured in stages. Many veterinarians use the IRIS scale, which has four stages. Blood work measurements like creatinine and SDMA (biomarkers for kidney function) allow your vet to assign your dog to a particular stage which will determine the exact treatment.
Dr. Klein explains, “The stages determine how well the kidneys can filter waste and extra fluid from the blood. As the stages go up, the kidney function worsens. In the early stages of CKD, the kidneys are still able to filter out waste from the blood. In the latter stages, the kidneys must work harder to filter the blood and in late stages may stop working altogether.”
How Is Kidney Disease in Dogs Treated?
Dialysis (a medical procedure that removes waste products and extra fluid from the blood) is far more common in humans than in dogs, although peritoneal (kidney) dialysis can be performed in some cases. On rare occasions, surgical kidney transplant is possible in dogs.
But Dr. Klein specifies that depending on the type and stage of kidney disease, the main treatments for CKD are diet changes and administration of fluids, either directly into the veins (intravenous) or under the skin (subcutaneous). “The balancing and correction of electrolytes are extremely important in the management of kidney patients,” he explains.
Proper nutrition is needed, and there are many available diets formulated for cats and dogs with kidney issues, some by prescription only. Your veterinarian can help guide you to the most appropriate diet for your pet.
Because kidney disease, particularly in the late stages, can cause a dog to lose their appetite, it can be difficult to encourage your dog to eat enough. Dr. Klein advises, “There are medications used as appetite stimulators available, such as the prescription drug mirtazapine. Capromorelin has recently been FDA-approved for dogs to address appetite in chronic kidney disease.”
When Do You Need to Call Your Vet?
The prognosis and expected life span for a dog with kidney disease depend on the type of disease, the speed of progression, and underlying conditions present in the dog. However, the more serious the disease, the poorer the outcome. That’s why it’s so crucial to catch the illness early on.
According to Dr. Klein, “In chronic kidney disease, there are methods, such as diets and medications, that can be used to lessen the burden of work the kidneys need to do and may help slow down the progression from one stage to the next. In acute kidney disease, there is less time and fewer choices available to prevent further damage to the kidneys and to try to jump-start the kidneys to get them to function normally.”
Regular veterinary exams, including bloodwork, are an excellent way to spot kidney problems before the outward symptoms become apparent. And if you notice any of the above signs, don’t hesitate to get your dog to the vet for further testing. It can make a huge difference in preserving kidney function and your dog’s well-being for as long as possible.