The end stages of kidney disease in dogs do not need to necessarily cause helpless feelings or cause deep discouragement in dog owners. Knowledge is power and ultimately becoming aware of what to expect during these difficult times can help provide a sense of security due to the possibility of having things better under control. There are several ways that dogs in the final stages of renal disease can be helped cope better with their condition while keeping in mind the main goal of managing any discomfort. Following is some information about the end stages of kidney disease in dogs, what to expect and options to help affected dogs.
The End Stages of Kidney Disease in Dogs
Chronic kidney disease (CKD) is not a death sentence for affected dogs. This condition can be successfully managed allowing dogs to survive for many months to years. The life expectancy of kidney failure in old dogs is variable based on several factors such as the dog's overall health, whether the condition was diagnosed at an early or advanced stage, elected treatments and other significant variables.
The life expectancy of an old dog with kidney failure is therefore somewhat unpredictable. Some dogs tend to remain stable for several years with treatment, while some other may decline quite rapidly. Most dogs though do seem to do quite well, and it may take 1 to 2 years before the dog's kidneys are to the point of no longer functioning, explains veterinarian Dr. Susan.
Currently, the International Renal Interest Society (IRIS), an organization dedicated to advancing the scientific understanding of renal diseases affecting small animals, has created a staging system for kidney disease affecting cats and dogs. The stages of kidney disease in dogs are four, and therefore, the end stages of kidney disease likely encompass stages three and four when toxins keep accumulating and affected dogs develop more prominent symptoms which ultimately lead to a cascading chain of events.
While many chronic cases of kidney failure follow such stages and therefore progress gradually, there are cases where the disease may suddenly take a turn for the worse. In these circumstances, it's referred to as an "acute on chronic" case where dogs per-acutely (suddenly) worsen despite suffering from a chronic disease process.
Signs of the End Stages of Kidney Disease in Dogs
Chronic kidney disease in dogs is an irreversible and progressive condition. As the kidneys fail, they begin functioning at minimum levels. For example, at stage three, the kidneys are generally functioning only between 15 and 25 percent, whereas, at stage four they are only functioning at less than 15 percent.
With such a lowered functioning ability, the kidneys are no longer able to filter all the toxins and waste products from the dog's body and this leads to the more noticeable signs seen in the end stages of kidney disease in dogs.
Many of these signs occur as a result of uremia, the high levels of urea in the blood. In normally functioning kidneys, urea, (a waste product from the breakdown of protein) is sent out into the urine courtesy of the kidneys.
In advanced kidney failure, because the kidneys are not functioning well, blood urea nitrogen BUN and creatinine (a waste product from the breakdown of muscle tissue) end up in the dog's bloodstream instead. This leads to several complications that get progressively worse as the kidney impairment progresses. Following are some signs of end stages of kidney disease in dogs.
Gastrointestinal problems are one of the most common signs of end stage kidney disease in dogs and is due to the toxic effects of waste products such as urea and creatinine (as discussed above) accumulating in the dog's bloodstream.
In end stage kidney failure, affected dogs will lose their appetite. Dogs may become selective about what they want to eat and their appetite may wax and wane throughout the day. Due to reduced caloric intake, affected dogs will consequently start suffering from weight loss.
Other concomitant problems contributing to loss of appetite include the strong nausea and vomiting, as often seen in dogs with kidney disease, that is often referred to as uremic gastritis. Vomiting may not be seen much in the earlier stages, but it becomes more common in the later stages.
Because dogs may develop ulcers in their stomach or ulcers in the mouth, it is possible to also see blood in the vomit. Some dogs with severe uremia may also develop diarrhea (uremic enterocolitis).
A kidney failure progresses, more and more kidney function is lost. Because the kidneys are working less, they lose the ability to concentrate urine and this leads to the production of urine that is more dilute (like water). How much the kidneys are still working in concentrating urine can be determined with a test that's called a urine specific gravity test.
Affected dogs will be drinking more than before and then forming more urine which as mentioned is often very dilute. Diluted urine may lead to annoying bladder infections which are commonly seen with kidney disease. This is because as the urine dilutes, it loses its natural acidity that helps keep pesky bacteria from invading.
Signs of these bladder infections often go undetected because, with diluted urine, dogs are less likely to urinate frequently in small amounts, strain, etc) but rather tend to just show signs of increased urine volume that is associated with the disease.
It may sound odd for a dog to develop high blood pressure, but chronic kidney disease (CKD), is the most common cause of high blood pressure in dogs and high blood pressure is the most common complication of chronic kidney disease. Arterial hypertension has been reported in 50 to 93 percent of dogs with chronic kidney failure.
In the end stages of kidney failure in dogs it is therefore important to keep them on blood pressure lowering medications. It may be difficult to administer these if the dog is no longer eating though. For those willing to try, blood pressure medications (like benazepril/enalapril) can be compounded into a transdermal form that can be rubbed on a dog's ear and absorbed through the skin.
Supplementation of omega 3 fatty acids may as well help reduce blood pressure and decrease inflammation. Something worthy of a discussion with a vet for specific recommendations.
In the end stages of kidney failure in dogs, dogs may develop several other symptoms. Foul breath that smells like ammonia is referred to as "uremic breath." It is caused by the accumulation of blood urea nitrogen in the bloodstream due to the compromised kidneys.
Some dogs develop painful mouth ulcers associated with kidney disease which can make eating painful and exacerbate the loss of appetite. Other symptoms include neurological signs such as tremors, seizures, and behavioral changes and eye problems due to high blood pressure.
When kidney function is lost, and the kidneys are no longer good at getting rid of excess phosphorus, phosphorus levels begin to rise and this may cause faster progression of kidney failure. Due to this, vets often recommend,dietary phosphorus reduction along with dietary protein reduction (kidney diets are often recommended, K/D is one of the best known, but other ones include Royal Canin Renal, or Purina NF), although many dogs lose their appetite in the late stages and refuse to eat these.
The dog's kidneys also play an important role in red blood cell production. The kidney produces an important hormone known as erythropoietin which tells the bone marrow to produce more red blood cells. When kidney function is impaired, production of erythropoietin is compromised. It is therefore not unusual for dogs to become anemic as the condition progresses. Decreased platelet function may be seen as well leading to bruising and bleeding.
Did you know? While there aren't many facilities offering dialysis for dogs as it happens with humans, more and more veterinary specialty centers are offering hemodialysis for dogs with kidney problems, but this trend remains rare due to considerable costs.
Help for the End Stages of Kidney Disease in Dogs
Keeping in touch with the vet is important during the end stages of kidney disease in dogs. Should the disease show signs of progressing, it may help to get some lab work done (blood and urine test to check kidney values) to see where the dog stands.
If the case warrants it, hospitalizing the dog with aggressive intravenous fluid support for 2 to 3 days can help get the dog fully rehydrated, return the dog's electrolytes back in check and control the nausea, points out veterinarian Dr. Joey.
Sometimes, this can help return dogs to a pre-crisis state, and in the best case scenario, the dog may do well for some time as long as subcutaneous fluids are given on a daily to several- times- a -week basis. Fluids help as they help affected dogs excrete some uremic toxins, and therefore, improves their quality of life.
Affected dogs should also be kept on several medications such as anti nausea medications (antacids like famotidine and metoclopramide to increase gastric motility), blood pressure medications, phosphorus binders and potassium supplements. The costs of all these medications and fluid treatments can surely easily add up. It is possible to cut some corners though by supplying subcutaneous fluids at-home.
A dog owner's finances should be therefore factored in. Not all dog owners can afford such treatments and it's reasonable at some point to decide to stop and do no more and opt for euthanasia considering that these treatments offer only short-term relief and ultimately for an incurable condition that won't get better.
When kidney disease is allowed to progress, affected dogs may linger for some time, nibbling on a bit food here and there and drinking. They tend to become skin and bones and eventually stop eating and drinking altogether, eventually succumbing to starvation and dehydration. Euthanasia is often offered before dogs reach this point.
- Diagnosis and Treatment of Systemic Hypertension Brown, Scott A. et al.Veterinary Clinics: Small Animal Practice , Volume 28 , Issue 6 , 1481 - 1494
- Advances in Blood Purification - Not Only Dialysis, Veterinary Technician Back to School Seminar
Carrie A. Palm, DVM, DACVIM, Department of Medicine and Epidemiology, University of California-Davis
School of Veterinary Medicine