Understanding the 4 stages of kidney disease in dogs

A part of agreeing to pet parenthood means doing your best to protect your pup from surprise illnesses, like acute kidney disease or age-related conditions like chronic kidney disease (CKD). 

Acute kidney disease happens when dogs get into foods or chemicals they’re not supposed to. But luckily, if it’s caught early enough and treated aggressively, pups can recover.

Unfortunately, the latter happens as some dogs get older, but there are ways to prepare and possibly prevent it from happening.

Keep reading to learn how to protect your pup against kidney disease (in any form) and the four main stages. 

‍What causes kidney disease in dogs? 

“The most common reason for kidney disease [also called chronic kidney disease (CKD)] is age-related loss of function,” Dr. Emily Singler, VMD, Fetch’s on-staff veterinarian, says. 

Kidneys are made of small filtering units, which filter substances out of the blood and urine, Dr. Singler explains. However, as a dog ages, the filtering units, known as nephrons, can stop working effectively. 

With the loss of some nephrons, dogs’ kidneys can still function, but when too many stop working, the kidneys can’t filter blood as well. Because of this, toxins that are usually filtered enter the bloodstream, leading to sickness.

Without adequate nephron function, the kidneys can’t conserve water, leading to dehydration, despite dogs consuming a lot of water. Unfortunately, CKD is irreversible and will continue to worsen over time.

Acute kidney disease (also known as acute renal failure), which can happen when a dog consumes toxins (like grapes, raisins or antifreeze), can be cured if caught early and treated aggressively in the hospital. But if too much damage has occurred, it can lead to CKD. 

It’s important to be cautious about vitamin D toxicity in dogs, Dr. Singler adds. Rodent bait or any human supplements usually have this ingredient, which can cause acute kidney disease. 

Antibiotics, anti-inflammatories or heart medications have a potential risk of causing kidney injury. However, the chances are low, especially if you're administering the medicine correctly, but you'll want to talk to your veterinarian to be sure that you're following the proper serving recommendations.

Infections like, leptospirosis, Lyme disease, Rocky Mountain spotted fever or urinary tract infections (UTIs), can also contribute to kidney disease.

‍The stages of kidney disease in dogs

There are four stages of kidney disease. The earlier phases might not show kidney disease symptoms, however, as the condition worsens, more evident signs will appear. 

‍Stage I: Usually, there’ll be no signs of kidney disease, and dogs will continue to act normal. If you bring them to the vet’s office, their blood work can appear regular, too. 

Ask your veterinarian about testing your pup’s symmetric dimethylarginine (SDMA) levels, which can indicate kidney disease. Having lab work done to test your dog’s urine for protein or low-concentration can also test for the condition. 

‍Stage II: During this period, there are still no signs of kidney disease, but the dog's kidney levels will continue to increase. 

‍Stage III: Signs become more apparent as the kidney values in bloodwork elevate. You might notice changes in your dog, like drinking more water (and going to the bathroom more than normal), weight loss, decreased appetite, lethargy, bad breath and vomiting. 

“These signs can all be associated with other diseases, too, so it's important to check with your veterinarian to determine if it's kidney disease or something else,” Dr. Singler adds. 

‍Stage IV: Signs are at their worst because there are severe elevations of kidney values in bloodwork. 

Kidney failure can also cause painful ulcers in a dog’s mouth and make them feel sick, nauseous and weak, leading to poor quality of life in the later stages.

‍RELATED: These are the 4 main causes of kidney disease in cats

How to treat kidney disease in dogs

“The treatment will depend on the severity and cause of the kidney disease,” Dr. Singler says. 

If a dog doesn’t have clinical signs yet, they may be able to go on a prescribed diet, which limits ingredients that kidneys have a challenging time processing and therefore supporting them. 

A hospital stay, where a pup might have IV fluids and other medications, might benefit dogs who are sick, lethargic, vomiting and haven’t eaten, Dr. Singler says. Pet parents may also be taught to give subcutaneous fluids (aka fluids given under the skin) to pets instead of an IV, at home to help them stay hydrated. 

Acute kidney disease should be treated aggressively in a hospital, which usually includes IV fluids and any supportive medication. If the condition is completely healed, dogs may not need other treatments. 

‍How to prevent kidney disease in dogs

Keeping your dog healthy by maintaining a healthy weight, feeding them a quality diet and following medication guidelines are ways to prevent kidney disease. 

Avoid giving your pup grapes or raisins, and keep them away from areas where these foods are stored to prevent acute kidney disease. Call poison control if your dog eats these foods and get them to a vet immediately. The vet may be able to get the dog to vomit what they had eaten and prevent serious disease from occurring.  

“Don't let your dog have access to antifreeze,” Dr. Singler says. “It tastes very sweet, and animals are drawn to it.” Call poison control and head to your emergency hospital immediately if your dog gets into this chemical.