A pet's kidney function tends to deteriorate over time and with age. And when kidneys—the organ responsible for filtering waste, maintaining fluids, and regulating the acidity of blood—fail, the homeostasis of a dog's body is thrown out of whack.
What Is Kidney Disease?
Kidney disease, or renal disease, can be chronic or can be the result of acute trauma, such as poisoning, infection, or heart failure. Either way, early diagnosis and prompt treatment are crucial to assure a good quality of life for your pet, while also extending its duration. If left untreated, kidney disease can lead to a slew of other illnesses (like anemia and cardiovascular complications), eventually resulting in death.
Symptoms of Kidney Disease in Dogs
A change in urination and drinking habits is one of the first signs that something is off. If you notice your pet coming down with unquenchable thirst and frequent and dilute urination, watch it carefully for other symptoms. Increased urination may also accompany lethargy, as a sick pet just feels crummy and may not want to participate in normal play. A loss of appetite and gastrointestinal upset may also be a sign of kidney disease. Your dog may accidentally go on the floor. Advanced renal failure usually presents with mouth sores, seizures, breathing problems, dementia, and other signs that your pet is struggling. If any of these signs are present, take it to the vet immediately.
Causes of Kidney Disease
Acute renal failure can happen at any age and can be the sign of poisoning (from antifreeze or pesticides), trauma (such as a fall or getting hit by a car), rapid dehydration in extremely hot weather, a blockage or infection in or near the kidneys, or excessively low blood pressure due to heart failure. When acute issues are diagnosed and treated promptly, kidney complications can often be reversed.
Chronic kidney disease, however, is often found in dogs 10 and older and it usually develops over several years. The exact cause of senior renal disease is unclear, but it could result from a previous infection or blockage that wears down the kidneys. It could also be part of a deeper issue, like high blood pressure, thyroid disease, or cancer. Certain breeds of dogs, such as English cocker spaniels, bull terriers, and Shar Peis, are predisposed to chronic kidney disease.
If you notice signs of kidney disease in your pet, don't wait long to call the vet. Some cases of acute renal failure can be cured. Chronic kidney disease, however, cannot be cured but can be managed in a way that assures a happy, healthy life.
A trip to the vet may involve blood and urine tests, an X-ray or ultrasound, and perhaps a biopsy to see if the issue is acute or chronic. Upon diagnosis, your vet will asses the stage of kidney failure and provide IV fluid therapy, in all cases, to deal with dehydration.
There are four stages of kidney failure for pets.
- Stage one and two mean the kidneys have not failed yet.
- Stage three indicates your dog is closer to kidney failure.
- Stage four means kidneys are failing.
Next, sub-Q fluids may be administered by injection under the skin. Often, the vet will instruct you on the proper administration of sub-Q fluids so that the injections can be performed at home. Fluid therapy will continue until your dog's body reaches its correct level of hydration and homeostasis. Follow-up visits, complete with blood and urine tests, will determine this.
Once initial symptoms are stabilized, pets with chronic renal failure may be prescribed benazepril—a vasodilator that makes it easier for the heart to pump blood through the body—to increase the blood flow to the kidneys and help them function more efficiently. Bezaprine also helps lower blood pressure, in the instance of heart disease or high blood pressure. Other medicines may also be given to treat anemia, gastric ulcers, and nausea that may result from renal failure. Drug maintenance, a diet low in phosphorus and protein, and supplementation of vitamin D and omega-3 fatty acids will, in most cases, help an older pet with chronic renal failure.
Side Effects of Benazepril Use
As with most prolonged drug use, side effects are common. Watch out for gastrointestinal upset, such as vomiting, diarrhea, and lack of appetite. More serious side effects can consist of weakness, hypotension (low blood pressure), elevated blood potassium levels (hyperkalemia), and, in extreme cases, kidney damage. Monitor your dog closely for signs of side effects and make sure to have it examined periodically by your veterinarian.
Benazepril is also known to pass through the placenta to any developing fetuses. Do not use during pregnancy or lactation.
How to Prevent Kidney Disease
Renal failure in domestic animals has reached epidemic proportions. Poor diet, environmental toxins, dirty water, inbreeding, and a high vaccination load can all contribute to overload on the kidneys. That said, feeding your pet a high-quality, grain-free protein diet prevents excessive waste buildup, taking stress off of the kidneys. Serving your pet wet food, providing round-the-clock access to clean water, and helping it maintain a proper weight can also help prevent the development of kidney disease.
Chronic Kidney Disease and Failure (CKD, CRF, CRD). Washington State University College of Veterinary Medicine
CKD Risk Factors. International Renal Interest Society
Renal Dysfunction in Small Animals. Merck Veterinary Manual
King, J N et al. Effects of Benazepril on Survival of Dogs with Chronic Kidney Disease: A Multicenter, Randomized, Blinded, Placebo-Controlled Clinical Trial. Journal of veterinary internal medicine vol. 31,4 (2017): 1113-1122. doi:10.1111/jvim.14726
Summary of Product Characteristics. Health Products Regulatory Authority