Kidney failure is an irreversible process that affects about 1 in 200 dogs of all ages and is far more common as dogs age. It’s important to get symptoms of kidney disease checked out by your veterinarian as early diagnosis can help your pet survive longer.
Moderate to severe
Table of Content
- Kidney failure symptoms start when two-thirds of the kidneys are no longer working
- It’s not usually known what causes the initial damage that results in kidney failure
- Kidney disease requires diagnosis by a veterinarian
- Kidney failure is not treatable, but management with dietary change and medications can improve survival times and quality of life
Common in older dogs
Symptoms & types
Kidney failure is the end stage of a disease process, where the kidneys are so damaged that they are no longer functioning properly. It may also be called chronic kidney disease (CKD) or chronic renal insufficiency.
Kidney failure in dogs is relatively common, affecting around 1 in 200 dogs in the general population. As dogs age, they become more likely to get kidney disease. Dogs over 12 years old are five times more likely to be diagnosed with CKD than those who are 7-12 years old.
The kidneys are a pair of organs that filter your dog’s blood. They remove waste products in the form of urine and concentrate that urine to preserve water in the body. The kidneys also have a role in new red blood cell production as they secrete a hormone that signals the body to make new red blood cells.
Over time (hence ‘chronic’), and due to injury, disease, toxins, and even changes in blood flow, the kidneys become damaged, and then scarred. By the time your dog shows signs of kidney failure, the kidneys are so damaged that only a third of the kidney is working properly. The symptoms of kidney failure you might see are:
- Drinking more
- Urinating more
- Smelly breath
- Poor coat
- Weight loss (and muscle loss)
- Dog Vomiting
Acute kidney injury (AKI), or acute renal failure, happens suddenly when the kidneys become damaged very quickly. This is usually due to toxins like raisins or some diseases like leptospirosis. Acute kidney damage is much rarer than chronic kidney disease. In AKI, the kidneys can sometimes recover, given sufficient support – they don’t have the scarring or long-term damage. The signs of acute kidney damage you might see are:
It can sometimes be difficult to decide whether kidney damage is acute or chronic. In general, dogs with CKD are older, and they’re ‘not themselves’ with a few niggling minor concerns like drinking more. In contrast, dogs with AKI can be young and are usually fine one day, then extremely ill the next.
Understanding the diagnostics
If your vet suspects your dog has kidney disease, they will recommend a blood test. There are several biomarkers in the blood that can detect kidney disease. Urea, creatinine, and SDMA should be excreted by the kidneys – increases in these values suggest the kidneys are no longer doing their job properly. The higher the result, the worse the damage.
Another important test your vet will perform will be a urine test. Damaged kidneys can’t concentrate urine, so your vet will examine the urine’s specific gravity to see how concentrated it is. They will also check for protein in the urine as this can ‘leak’ out through damaged kidneys. Dilute urine with lots of protein makes kidney disease very likely.
Once your vet has determined your dog has kidney failure they’ll want to ‘stage’ them. The dog kidney disease stages were developed by the International Renal Interest Society (IRIS). Dog renal stages run from 1 to 4, with 4 being the worst. Your vet will determine how bad your dog’s disease is based on their blood and urine results, and possibly other tests like blood pressure. Determining the stage allows your vet to make a prognosis and guides the best treatment.
Learning About The Causes
Kidney failure is the end result of cumulative damage and scarring that happens to the kidneys over a long period of time. It’s usually not possible to tell what injures the kidneys in the first place. In dogs, the signs of kidney disease are generally not noticed until two-thirds of the kidneys have lost function, and by this time the initial injury has long passed.
Anything that damages the kidneys can contribute to kidney failure in dogs. Examples include:
- Heat stroke
- High or low blood pressure
- Kidney infection
- Diseases such as heart disease
We also know that canine chronic renal failure is slightly more common in Cavalier King Charles Spaniels and Cocker Spaniels. Some studies have found that smaller dogs are more likely to get renal disease.
Best Treatment Options
Renal failure is an irreversible process, and there is no cure. However, its progression can be slowed with some management options.
The most important change is to diet. Dogs with renal failure should be placed on a prescription kidney diet. These diets contain carefully chosen proteins and restricted phosphorus and sodium to help protect the kidneys. If the restricted phosphorus isn’t possible or isn’t sufficient, phosphate binders can be added to the food to prevent the body from absorbing the phosphate.
Another essential treatment for your dog with kidney failure is to always ensure they have enough water. Dogs with kidney failure will drink a lot of water, and it can be hard to keep up with their requirements. Add extra water bowls to ensure there’s always water nearby and they don’t run out when you are out of the house. It may be tempting to stop giving so much water as your dog will be peeing a lot, but this is risking dangerous dehydration.
Medications may also be required. Dogs that are throwing up may need anti-sickness drugs, while dogs with high blood pressure may need tablets to bring their blood pressure down. Dogs with very poor blood results may be recommended a drip (intravenous fluids) to help to rehydrate them. Their blood will be tested again after 24-48 hours to assess the effect of the fluids.
It’s important to recognize that renal failure will eventually be fatal to your dog. Dogs can live for months or even years with renal failure, depending on how early they were diagnosed and how severe their disease is. However, the symptoms of renal failure can be unpleasant and damage your dog’s quality of life. Knowing when to euthanize a dog with renal failure is difficult, but you should consider your dog’s quality of life and communicate your concerns to your vet, who will help you decide when it’s time to say goodbye.
Kidney failure is relatively common, especially in older dogs. It’s the end stage of a long process, and it’s too late to reverse the disease. Instead, looking after the remaining portion of kidney is the only option. With prompt treatment as soon as signs are noticed, it’s possible for dogs with kidney failure to live for several years.
How long a dog lives with kidney failure depends on the stage they were diagnosed at and how fast their individual disease is progressing. In one study, the average survival was about seven months.
Dogs with failing kidneys will need to drink more and urinate more than they used to. They may become tired, their coat may be poor, they may lose weight, and vomit regularly.
We don’t know whether kidney failure in dogs is painful. What we do know is that the signs can be unpleasant and distressing, and this leads many people to opt for euthanasia when medications are no longer working.
If your dog has kidney failure and is reaching the end of their life, you may see a deterioration in their condition. If your dog was on medications, the signs such as vomiting may return, even though they are still taking their drugs. It’s likely their appetite will get worse, and they may continue to lose weight. Most dogs with kidney failure are euthanized, as the disease is distressing for both pet and owner.