You should know that there are TWO types of kidney disease. One that is “acute” meaning quick or rapid onset, and one that is “chronic” meaning that the disease has been going on for a long period of time. Acute onset Kidney Disease often happens due to immediate trauma – think of a car crash where the kidneys were damaged, or if your pup ingested a toxin (like grapes!), or if your pup gets a disease like leptospirosis. If not caught quick enough or if permanent damage is caused acute kidney disease can progress to chronic kidney disease. But largely Chronic Kidney Disease is seen as either a heritable or age-related condition.
WHY DO DOGS GET CHRONIC KIDNEY DISEASE?
Chronic Kidney Disease in dogs, or CKD is most often seen as a progressive disease that usually occurs due to long-term inflammation and oxidative stress. It can also be a side effect of -or- be exacerbated by other conditions such as: chronic urinary/kidney infections (bacteria/fungal), dental disease, autoimmune disease, inflammation/irritation from urinary stones, infectious diseases (like Lyme disease), or certain types of cancer.
Once CKD starts it slowly progresses through four different stages of disease. Chronic Kidney Disease is not a treatable disease (unlike Acute Kidney Disease), it can simply be managed to prolong-life and improve overall quality of life.
When caught EARLY owners are able to be proactive to both nutritional and medical management, and are also able to be mindful of future triggers that may speed up the progression of the disease.
ARE CERTAIN BREEDS PRE-DISPOSED TO KIDNEY DISEASE?
Though much less common than age-related CKD there are forms of heritable kidney disease. Depending on the severity of the condition these diseases could greatly reduce the lifespan of your pup, and even make routine procedures such as spay/neuter or dental cleanings much more risky. In order to mitigate this risk speak to your veterinary about pre-anesthetic testing – such as blood work and urinalysis.
This happens when the structures within the kidney do not fully develop within the womb. This can be an early-onset form of kidney disease, largely seen in younger dogs (less than 2 years of age), however it can be seen in young adults if the condition is very mild. Overall life expectancy is short for a majority of cases unless the dog undergoes kidney transplant.
Breeds associated with Renal Dysplasia: Alaskan Malamute, Beagle, Border Terrier, Boxer, Cairn Terrier, Chow-how, Doberman, Golden Retriever, Lhasa Apso, Miniature Schnauzer, Shih Tze, Wheat Terrier, and Standard Poodle.
This happens when immune complexes form on the glomerulus, and then by interacting with other compounds within the body such as platelets white blood cells, and fibrin – cause damage to the glomerulus. This damage causes the glomerulus to not be able to perform it’s main function – which is to filter waste products from the blood stream to be excreted by the urinary tract.
Breeds associated with Glomerulopathies: Basenji, Beagle, Bernese Moutian Dog, Brittany Spaniel, Bull Mastiff, Dalmatian, Cocker Spaniel, Springer Spaniel, Newfoundland, Pembroke Welsh Corgi, Rottweiler, and Samoyed.
Polycystic Kidney Disease:
This happens when small fluid-filled cysts early in life. As the puppy gets older these cysts become larger and multiply – as this happens they replace normal kidney tissue. This decrease in healthy kidney tissue leads to a decreased ability to filter waste products to be excreted.
Breeds associated with Polycystic Kidney Disease: Bull Terrier, Cairn Terrier, West Highland Terrier.
This happens when small proteins called amyloids are deposited outside of cells and organs, which distrupt organ fuction.
Breeds associated with Amyloidosis: Beagle, English Foxhound, Shar Pei, Bulldog
CLINICAL SIGNS OF KIDNEY DISEASE IN DOGS:
The first two stages of kidney disease in dogs are actually mostly “silent” – little to no clinical signs are actually seen until the later stages of kidney disease. Thus it is very important to do routine testing (blood work and urinalysis) to check for early indicators of disease.
- Not Eating
- Weight Loss
- Bad Breath
- Increased Urination
- Increased Frequency of Urination
- Pale Mucous Membranes
- Dark sticky feces (melena)
- Oral Ulcers
- Dull Hair Coat
- Poor Body Condition
- Inflammation to the Mouth/Gums (Stomatitis)
Depending on your dog’s presentation and clinical signs your veterinarian will probably start with some simple tests to establish the severity of your pet’s condition. However additional testing may be required for additional infections (liek if they suspect a urinary bacterial infection), or other conditions (such as a possible cancer or a urinary/kidney stone.
- Full Chemistry Panel – including CRE (creatine), BUN, and SDMA
- Complete Blood Cell Count (CBC)
- Urinalysis – including both a dip-stick and microscopic evaluation
- Urine Protein to Creatinine Level
Optional Further Diagnostics
- X-rays (radiographs)
- Blood Pressure
- Urine Culture
- Meet patients overall nutritional needs
- Alleviate clinical signs and improve quality of life
- Slow progression of the disease
STAGES OF KIDNEY DISEASE IN DOGS:
There has been YEARS of research that has been done on kidney disease in dogs – and still today more research is being done on different ways to improve quality of life and extend a dog’s life when diagnosed with this condition. Researchers have come up with a staging system to allow for easier treatment of the condition – this allows veterinarians to slowly increase interventions and nutritional management strategies over time. Because researchers have found that too much restrictions to the diet, too early may cause side effects – like poor body condition and a pet who doesn’t want to eat readily.
STAGE ONE KIDNEY DISEASE:
- CRE <125 µmol/l
- CRE <1.4 mg/dl
- SDMA <18
After being diagnosed with possible stage one kidney disease a pet is usually placed on a monitoring schedule – this may be monthly, or every three months depending upon the original findings on the diagnostics. Most dogs that are monitored are looked at for:
- Blood Pressure
- Urine Protein:Creatinine Ratio
- Urine Specific Gravity
- Hydration Status
DISCUSS DISCONTINUING MEDICATIONS PROCESSED BY THE KIDNEYS
The next thing that most veterinarians will do is evaluate the medications your pup is currently on to make sure that none of them are potentially toxic to the potentially damaged kidneys.
TREAT OTHER ABNORMALITIES RELATED TO CLINICAL SIGNS
Oftentimes the first thing we see when the lab values start to creep up is that there is another disease or condition that is exacerbating the problem. This conditions fall into two categories – one is conditions that decrease blood flow to the kidneys (pre-renal) – such as low blood pressure, heart failure, or dehydration. The second is conditions that affect urine leaving the system – this could be something like kidney stones, a urinary obstruction, bladder stones, or a bladder/prostate/ureter cancer.
When considering nutritional management of kidney disease for dogs it can be complicated. There are general treds and recommendations, however there are exceptions as well. The best thing to do is the work with your veterinary teacm and discuss which type of diet would be best for your dog based on THEIR lab work.
For example if your pup is showing Protein in their urine at stage 1 kidney disease, protein restriction may need to be considered sooner than a dog without that finding. Or if your dog’s blood pressure remains table – there may be no reason why a low sodium diet is necessary. But generally speaking there a coupe items that can be implimented regardless of stage of disease. These are:
OMEGA 3 FATTY ACIDS
According to research omega 3 fatty acids – in particular EFA and DHA have powderful anti-inflammatory properties. These properties help to reduce oxidative stress and slow down the progression of kidney disease. Research suggests a dose of 40mg/kg EPA and 25mg/kg DHA, and highly recommends NOT using ALA since the conversion rates are poor. It is also suggested that the ideal omega 6 to omega 3 ratio is around 5:1 for kidney disease.
Since the main cause of kidney disease in dogs is oxidative stress due to chronic inflammation it makes sense that the addition of antioxidants which help mitigate oxidative stress would be helpful! According to research the addition of antioxidants can significantly extend life in dogs with kidney disease.
A new solution found to help with kidney disease in recent years has been the addition of fermentable fiber! Fermentable fiber basically allows the the gut, instead of the kidney, to break down nitrogen waste products. This can greatly reduce the “work” that the kidneys need to do, and can extend dog’s lives that have kidney disease.
If your dog is struggling with blood pressure issues, your veterinarian may consider using a lower sodium diet in hopes that it will help normalize your dog’s blood pressure. However you should know that this recommendation does not currently have any research supporting it’s use.
HIGH MOISTURE DIET
Often times with kidney disease dogs will loose fluids faster than the typical dog. This means that they are prone to dehydration – in order to combat this switching to a higher moisture diet can be advisable if possible. This usually means switching from a kibbled diet to a canned or fresh food diet – but it can also be as simple as adding in water to the kibbled diet that the pet is already eating.
There are four special considerations that you will need to keep in mind at the start if you have a dog that has kidney disease…
- If your dog becomes ill, they may need additional fluids given under their skin or into their vein in order to maintain their hydration status. Without which they could become VERY sick.
- If your dog’s blood pressure is high your dog may be placed on a lower sodium diet. Normal Blood Pressure should be less than 160 mmHg.
- If your dog’s urine has a high amount of protein your dog may be placed onto a lower protein diet. Normal Urine Protein is less than 0.5.
- Depending on how your dog responds to initial treatment your dog may need more medications in order to control their symptoms – such as blood pressure medications . Chronic Kidney Disease is largely a balancing act, and no two dogs will respond in exactly the same way.
STAGE TWO KIDNEY DISEASE:
- CRE 125-250 µmol/l
- CRE 1.4-2.8 mg/dl
- SDMA 18-35
- *DECREASED urine concentration
When your pup moves into stage two kidney disease, most of the recommendations will remain the same as in stage one, often times your veterinary will build off their established protocols. Now i have often when asked “Why not do it all at once?” – the truth is that doing too much too fast for dog’s with kidney disease can potentially have significant side effects, and even speed up the progression of the disease. Which is why monitoring regularly and routine checkups are so important.
There are not many major changes to dietary management at this point – other than your pup will probably be moved onto a prescription or specially formualted diet. This is because in order to do phosphorus restriction well – you cannot feed the typical commercially available food. Your veterinary will give you many different options depending on your dog’s needs. There are dry, canned and fresh food prescription diets available. The brands that I am currently aware of that produce kidney diets are: Hill’s, Purina, Royal Canin, Just Food For Dogs.
Each brand will have their own unique composition, and one food may be more appropriate for your pup than another. Keep in mind that a third option is always going to be working with a board certified veterinary nutritionist – you can find more info on how to get in contact a ACVN diplomat on my blog post on DIY dog food.
LOW PHOSPHORUS DIET
At this stage in the game it’s important to start helping your pup by removing some of the workload associated with processing phosphorus from your dog’s diet. Depending upon other values and clinical signs this may or may not be accompanied with a reduction in protein as well.
In some dogs a low phosphorus diet alone is unable to reduce phosphate levels into normal range. If that is the case your veterinarian may add on phosphate binders. These binders are aluminum hydroxide, aluminum carbonate, calcium carbonate, calcium acetate, and lanthanum carbonate. These supplements are given with all meals in order to actively bind phosphates before they can reach the bloodstream. ADDITIONAL MONITORING includes checking calcium to phosphorus concentration every month or so. Checking for aluminum toxicity, and calcemia.
STAGE THREE KIDNEY DISEASE:
- CRE 251-440 µmol/l
- CRE 2.9-5.0 mg/dl
- SDMA 36-54
- *DECREASED urine concentration
Once your pet is in stage three kidney disease your pet has advanced into the later stages of this disease – most likely your pup is experiencing clinical signs, and may have difficulty with everyday tasks, such as eating or drinking. In this stage we move into full nutritional management of kidney disease on top of the previous monitoring and management strategies from stages one and two. Your veterinarian will also be helping you manage your pup’s quality of life by offering different medications or supplements to make your dog more comfortable.
As things are definitely getting more significant by stage 3 kidney disease in dogs, we need to make some more significant changes. Meaning that protein restriction is now highly recommended, whereas before it was only recommended in certain situations – like in the case of protein in the urine. The challenge with protein restriction is that food tastes better when it is higher in animal proteins, and the amino acids found in proteins help with tissue repair. Studies have shown lower protein can lead to loss of overall body condition in dogs – which can lead to weakness and lethargy. HOWEVER studies have also shown that early protein restriction can extend life.
This the balancing act your veterinarian has to play – too low and your dog might stop eating well, become weak and lethargic – leading to a poor quality of life. Too high and your pup’s disease could progress quicker. Know that your veterinarian is going to do their best based on the information they have to help your pup live a high quality life despite their condition.
As your dog’s clinical signs get worse, some treatments your dog is given may be associated with clinical signs rather than directed associated with disease progression. Some of these include the management of:
- Metabolic Acidosis
- Dehydration via Fluid Therapy
STAGE FOUR KIDNEY DISEASE:
- CRE >440 µmol/l
- CRE >5.0 mg/dl
- SDMA >54
- *DECREASED urine concentration
This stage of kidney disease is largely about quality of life, your veterinarian is going to try to balance the treatment of your dog’s overall condition the best they can in order to extend their life as much as possible. Often dogs will rotate foods in this stage because your pup may associate their nausea/not feeling well with what they are eating. Hydration status can also very easily cause nausea – dehydrated pets will feel ill and will often go off food completely. This is why it is highly recommended to feed your pup a moisture rich diet – either in the form of canned, fresh or home-prepared.
Depending on your budget and your pet’s overall condition some additional options at this stage are…
- Feeding Tube Placement to Assist Eating
- Kidney Transplant
Chronic Kidney Diease in dogs can be a challenge for both you as a pet owner and for your veterinary team. However starting treatment early can potentially add on years to your pet’s life. So I highly recommend not only looking for clinical signs (where you most likely will see stage 3 kidney disease), but do routine labwork on your pup. Get a baseline for your dog’s values when they are young, and then recheck their values as often as you are able (during your pup’s yearly physical examination is ideal). The earlier he disease is caught the better position we are in for management of the disease.
I hope that you found this in-depth look at kidney disease helpful! If you enjoyed this article you can check out the blog posts below – I’m sure you will enjoy those as well. Joint the conversation on Instagram to ask questions, and join our community of like-minded pet parents! And if you don’t want to miss a post – make sure to subscribe to my email list – and get your FREE E-BOOK on how to do an at home Health Assessment on your dog. Hope you and your pups have an amazing day!
Veterinary Information Network “Kidney Failure in Dogs and Cats: Where to Begin”
Washington State University College of Veterinary Medicine “Chronic Kidney Disease and Failure (CKD, CRF, CRD)”
Veterinary Practice News “Treatment Guidelines for Chronic Kidney Disease in Dogs & Cats”
Veterinary Practice News “Nutritional Management of Renal Disease: An Evidence-Based Approach” Sherry Lynn Sanderson, DVM, PhD, Diplomate ACVIM & ACVN
VetFolio “Nutritional Management of Renal Disease – What to Feed and When to Start” Cailin R. Heinze, VMD, MS, DACVN
Veterinary Information Network “Nutritional Management of Renal Disease: Myths, Realities, and Tips for Success“ Denise A. Elliott, BVSc(Hons), PhD, DACVIM, DACVN
Veterinary Information Network “Renal Dysplasia in Shih Tzu Dogs” Veterinary Information Network “ Diagnosis and Management of Canine Glomerular Disease”