kidney disease in dogs weight loss
Chronic Renal Failure (CRF) in Dogs
What Is Chronic Renal Failure in Dogs?
Chronic renal failure (CRF), renal insufficiency, and chronic kidney disease (CKD) are all medical terms used to describe the same condition. It occurs when the kidneys are unable to perform their required tasks at the same level of efficiency as before.
Dogs have two kidneys located on either side of their abdomen, that play a vital role in filtering waste from the body. Additionally, the kidneys serve to regulate fluid, mineral, and electrolyte balance; conserve water and protein; and play an important role in maintaining blood pressure and red blood cell production by making a hormone called erythropoietin.
Dogs cannot survive without their kidneys, and unfortunately, kidney transplants are yet to be a viable solution. Dialysis (a treatment for failing kidneys including the removal of waste) is often expensive and is extremely rare in dogs. However, early diagnosis and intervention is key to help maintain your dogs quality of life.
Once diagnosed, CRF is then classified into four different stages based on severity of clinical signs and laboratory values:
Stage I: Clinical signs usually not apparent
Stage II: Some clinical signs noted
Stage III: Many clinical signs noted, and pets often feel sick
Stage IV: Majority of clinical signs noted, pets often present as a crisis
Causes of Chronic Renal Failure in Dogs
The term chronic in chronic renal failure means that the process has been ongoing, is progressive, and unfortunately, cannot be reversed. For some dogs, the disease could have occurred after a serious kidney injury such as from a severe infection (i.e., leptospirosis, pyelonephritis) or ingestion of a toxic substance such as anti-freeze, grapes, or raisins, and certain antibiotics.
For others, it could be inherited, such as with glomerular disease (a specific type of renal kidney disease) and amyloidosis (a rare organ disease) as seen in breeds like the Bernese Mountain Dog and Shar-pei.
For others, it could be attributed to underlying immune-mediated diseases, stroke-like events, or even from clotting disorders. In cases for newly diagnosed dogs the underlying cause will likely remain unknown.
Symptoms of Chronic Renal Failure in Dogs
Clinical signs are often related to the severity of the CRF stage, meaning there are additional and more severe signs noted with stages III and IV than there are with stages I and II. Dogs often exhibit symptoms including:
Foul breath
Weight loss
Decreased appetite
Some dogs may show muscle wasting and signs attributed to high blood pressure, such as vision loss and weakness.
How Veterinarians Diagnose Chronic Renal Failure in Dogs
CRF is often diagnosed based on routine blood work and a urinalysis looking specifically at kidney markers such as:
Blood urea nitrogen (BUN): A by-product of protein metabolism, higher values can often indicate kidney failure
Creatinine (CREA): Measures how well kidneys are filtering waste from blood
Phosphorous: Elevated phosphorus levels typically indicate kidney damage
Electrolytes (Sodium, potassium, chloride)
Calcium
Red blood cell count: A low red blood cell count may indicate kidney failure
Symmetric dimethylarginine (SDMA): An additional test to help determine if kidney disease is present; it can be used for early detection of kidney disease
Urine specific gravity: A marker of how diluted or concentrated the urine is. Usually the higher the number, the more concentrated the urine is and the greater ability of the kidney to conserve water.
Your veterinarian will most likely recommend additional diagnostic testing, including:
A urine protein to creatinine (UPC) ratio to quantify how much protein is being lost in the urine
A urine culture, as dogs in CKD are more likely to acquire urinary tract infections
A blood pressure evaluation
Radiographs or abdominal ultrasound to screen for kidney stones or infarcts (areas of dead tissue)
Treatment of Chronic Renal Failure in Dogs
Dogs with CRF are generally older and have other ongoing issues, such as arthritis or liver disease, and so the management of CRF can be challenging. However, CRF can be managed, mostly with the aid of medications, diet, and hydration.
Specific management is geared toward each stage of the disease, with each progressive stage recommendations built upon the previous stage recommendations. Any dog in any stage with an increase in either UPC (urine protein to creatinine ratio) or high blood pressure will most likely be treated with medication.
Throughout your dogs life, any disease process or illness that could affect his hydration should be treated promptly with IV fluids. Other drugs will be prescribed based on the dogs diagnosis since renal metabolism will be affected and can lead to overdosages and/or worsening of the kidney disease.
Additionally, for all stages, fresh water should always be available, drinking should be encouraged, and adequate nutrition should be given daily. Dogs diagnosed with CRF are most likely prescribed a kidney friendly diet, which may include feeding your dog a canned diet of wet food that contains additional water.
Recovery and Prevention of Chronic Renal Failure in Dogs
As chronic renal failure is not curable and often progressive (although the timeline is variable) in nature, dogs diagnosed early on will benefit from nutritional management and consistent veterinary attention, which may include more frequent check-ups and blood work.
Dogs in stages I and II may often be monitored for further progression of signs, and some may be given a prescription diet specifically geared to help the kidney, by limiting the amount of work they must do.
Many dogs can go on to have a decent quality of life for many months to years. Dogs in stages III and IV often require more medical and dietary assistance. If secondary anemia is present, erythropoietin injections can be given at the direction of your veterinarian.
Dietary supplements, and phosphorus binders (to treat high phosphorus levels) may also be given for low potassium. Anti-nausea and anti-emetic (anti-vomiting) medications can also be prescribed for dogs with a poor appetite, vomiting, or nausea. Fluids given either intravenously or underneath the skin can help dehydration. Because of the severity of signs often seen in dogs with stage III and IV, and the amount of care and effort required to support these dogs, some may be humanely euthanized.
Chronic Renal Failure (CRF) In Dogs FAQs
How long can a dog live with kidney failure without treatment?
Left untreated, dogs in kidney failure will die, usually within a few days to a few weeks. Death is often preceded by loss of appetite, dehydration, weight loss, vomiting, and multi-organ failure.
Can dogs recover from chronic renal failure?
There is no cure for CRF. However, if CRF is caught early and managed correctly, most dogs that experience kidney disease can go on to live a relatively normal life with some changes and long-term management.
Can chronic renal failure in dogs be reversed?
While CRF is not reversible, early treatment can provide your pet with a happier, longer, and fuller life. Regular, semi-annual checkups are key to early diagnosis and treatment of the development of chronic renal disease.
Featured Image: iStock.com/Korneeva_Kristina
WRITTEN BY
Michael Kearley, DVMVeterinarian
Dr. Michael Kearley graduated from the University of Florida College of Veterinary Medicine in 2013. He graduated with a certificate in...
Why Your Dogs Losing Weight and What to Do
Its normal for a dogs weight to vary a little bit over time. If you change their diet to one that isnt to their liking, theyll probably lose a few pounds. Or maybe they are staying inside more during the winter; in this case, theyll probably gain a little.
But what about a dog that keeps losing weight and you dont know why? Unexplained weight loss can be the first sign that a health problem is brewing.
Why Is My Dog Losing Weight?
Weight loss in dogs has many causes. Problems with a dogs diet, environment, and health could all be to blame. Here are a few of the most common causes of unexplained weight loss:
A problem with their food: Dogs may eat less when there is something they dont like about their food. A change in diet may be to blame, or perhaps a large bag of food has started to go bad before your dog has finished it. Feeding too little or giving your dog low-quality dog food can also lead to weight loss.
Stress:A dog thats anxious or stressed may find it hard to relax and eat because they feel like they always need to be on alert.
Exercise: Dogs that start exercising more but dont take in more calories will lose weight.
The environment: Dogs require extra energy to stay warm when they spend lots of time in the cold. Conversely, hot temperatures can reduce a dogs appetite.
Reproduction:Pregnancy and lactation (nursing puppies) put extra nutritional demands on dogs. If they dont take in more calories, they will lose weight.
Dental disease and other oral problems: Any problem that makes chewing and swallowing painful or difficult will discourage a dog from eating.
Intestinal worms and other parasites: Parasites get their nutrition from their hosts, which can lead to weight loss in dogs.
Cancer: Cancer cells use energy to grow and divide, and this means that the energy is not available to the dog, so they often lose weight. Cancer can also directly affect a dogs digestive system and appetite.
Gastrointestinal (GI) disorders: Problems that affect the functioning of the digestive tract can reduce a dogs appetite or their ability to digest and absorb nutrients. Inflammatory bowel disease, lymphoma, adverse food reactions, or partial intestinal blockages could be to blame.
Nasal problems: Any condition that affects a dogs ability to smell their food can lead to a reduced appetite.
Diabetes mellitus: The changes in glucose metabolism seen with diabetes mellitus frequently lead to weight loss in dogs, even when they have a good appetite.
Exocrine pancreatic insufficiency (EPI): When dogs have EPI, they dont produce enough of the digestive enzymes needed to break down food and absorb nutrients.
Infections: Bacterial, viral, or fungal infections can directly affect the GI tract and lead to weight loss. Fighting an infection anywhere in the body requires extra energy, and if dogs dont eat more, they will lose weight.
Kidney and liver disease: When the kidneys or liver dont function properly, waste products of metabolism build up in the bloodstream, which can make a dog nauseated and not feel like eating. Dogs with kidney disease may also lose protein in their urine, which can lead to weight loss.
Heart disease: Weight loss is common as heart disease progresses. The exact causes of this are unknown, but the condition goes by the name cardiac cachexia.
Addisons disease:Dogs with Addisons disease (hypoadrenocorticism) dont produce enough of certain types of adrenal hormones, which can lead to poor appetite and weight loss.
Hyperthyroidism: Although hyperthyroidism is rare in dogs, it can increase their metabolic rate and lead to weight loss.
Neurologic conditions: Any disease that adversely affects a dogs ability to eat and swallow can result in weight loss.
Is My Dog Too Skinny?
Regularly checking your dogs weight by using an accurate digital scale is the best way to monitor for weight loss or gain. However, evaluating a dogs body condition score can also help you determine if your dog is too skinny. In general, a dog might be too skinny if:
You can easily see their ribs or other bony points.
When looking down from the top, they have a very pronounced waist.
When looking from the side, they have an exaggerated abdominal tuck.
When to See Your Vet About Your Dogs Weight Loss
A little bit of weight loss isnt always an emergency. As long as your dog doesnt have any other signs of illness, you could try to change their diet or environment to see if it solves the problem. But there are times when you should get your dog to a veterinarian ASAP:
Puppies shouldnt lose weight! As they grow, puppies should be gaining weight, so call your veterinarian immediately if your puppy is losing weight or getting too skinny.
Weight loss in a dog thats older or has an underlying health problem is always concerning. The risk of serious diseases that cause weight loss increases as dogs get older.
Weight loss combined with symptoms of illness is never normal. Make an appointment with your veterinarian if your dog has difficulty breathing, vomiting, diarrhea, coughing, sneezing, weakness, lethargy, increased thirst and urination, or any other worrisome symptoms. If your dogs symptoms are severe, call a vet immediately to determine if you should head to the clinic right away.
Rapid or pronounced weight loss should always get your attention. Any health problem can lead to serious weight loss. Make an appointment with your veterinarian if your dog has lost more than 10% of their normal body weight or is losing 2% or more of their body weight per week. Heres what that can look like for dogs of different sizes:
Serious Weight Loss in Dogs
Normal Weight in Pounds | Current Weight in Pounds | Rapid Weight Loss |
10 | 9 | 0.2 pounds/week |
25 | 22.5 | 0.5 pounds/ week |
50 | 45 | 1 pound/week |
75 | 67.5 | 1.5 pounds/week |
100 | 90 | 2 pounds/week |
How Do Vets Treat Unexplained Weight Loss in Dogs?
A veterinarian will start by asking you a lot of questions about your dogs diet, appetite, environment, behavior, medical history, and any current medications (including parasite preventives) or supplements that you are giving. They will also determine how many calories your dog is taking in each day and if this amount should be meeting their energy needs.
Next, they will perform a complete physical examination and use the information they uncover to recommend treatment or further diagnostic testing. A basic laboratory workup includes a fecal examination, bloodwork, and a urinalysis. Additional testing can involve x-rays, ultrasound examinations, specialized lab tests for specific health problems, endoscopy, exploratory surgery, and tissue biopsies.
Whenever possible, veterinarians will recommend treatment for a dogs weight loss that aims to cure or at least improve its underlying cause. For example, they will prescribe a dewormer if a dog has intestinal parasites, dental care for damaged teeth, or antibiotics for a bacterial infection. Oftentimes, a change in diet can also help dogs regain the weight theyve lost. Options include:
High-calorie, nutrient-dense dog foods for generalized weight gain
Highly digestible diets when GI function is impaired
Dog foods with added fiber may be appropriate for some types of GI problems or for dogs with diabetes
Hypoallergenic dog foods made from novel ingredients, hydrolyzed proteins, or individual amino acids for food allergies and intolerances
Disease-specific diets like those designed to help manage kidney or liver disease
The right food and other treatments will depend on the specifics of your dogs case. Dont wait too long to get your dog the care they need. Its easier to manage a dogs weight loss when it hasnt had a chance to progress too far.
Featured Image: iStock/Capuski
