High BUN In Dogs: Causes, Symptoms and More

High BUN in Dogs

If you’re a dog owner, you know how important it is to keep an eye on your furry friend’s health. One thing your vet might mention during a check-up is BUN, or Blood Urea Nitrogen levels. But what exactly does it mean when your dog’s BUN levels are high? Let’s break it down.

What is BUN?

BUN stands for Blood Urea Nitrogen. It’s a measurement that indicates how well your dog’s kidneys are working. Urea nitrogen is a waste product that forms when the body breaks down proteins. Normally, the kidneys filter this waste out of the blood and into the urine to be removed from the body. So, when BUN levels are high, it could mean the kidneys aren’t doing their job properly.

What Causes High BUN in Dogs?

There are several reasons why your dog’s BUN levels might be elevated:

Dehydration: Just like in humans, when dogs don’t drink enough water, their body tries to conserve it. One way it does this is by making the urine more concentrated. However, this also means that waste products like urea nitrogen, which are normally diluted in urine, become more concentrated too. This can lead to higher BUN levels in the blood.

Kidney Disease: The kidneys are like filters for the body. They remove waste products and excess fluids from the blood, which are then excreted as urine. If the kidneys are damaged or diseased, they may not be able to effectively filter waste products, leading to a buildup of substances like urea nitrogen in the blood. This buildup can cause BUN levels to increase.

Urinary Tract Obstruction: When something blocks the urinary tract, such as a urinary stone or a tumor, urine can’t flow out of the body properly. As a result, waste products that would normally be excreted in urine, including urea nitrogen, accumulate in the bloodstream. This buildup can cause BUN levels to rise.

Certain Medications: Some medications, particularly those that are processed by the kidneys, can affect kidney function. For example, certain antibiotics or pain medications may have side effects that impair kidney function. When the kidneys aren’t working properly, they may not be able to effectively filter urea nitrogen and other waste products from the blood, leading to elevated BUN levels.

Symptoms of High BUN in Dogs

Here are some signs that might show up if your BUN levels are high because of kidney issues:

Increased Thirst and Urination: Your dog might be drinking more water than usual and needing to pee more frequently. This happens because the body tries to flush out the excess BUN through urine.

Lethargy: If your dog seems unusually tired or lacks energy, it could be a symptom of high BUN. This happens because the body is working hard to deal with the increased waste products.

Loss of Appetite: High BUN levels can affect a dog’s appetite. They might not show interest in food or eat less than usual.

Vomiting: Dogs with high BUN may vomit frequently. This can happen because the buildup of waste products can upset their stomach.

Weakness: You might notice your dog having trouble standing or walking, or they may seem weaker than usual. High BUN levels can affect muscle function.

Bad Breath: Sometimes, dogs with high BUN levels might have a foul-smelling breath. This can be due to the buildup of waste products in the body.

Weight Loss: If your dog is losing weight despite eating normally, it could be a sign of high BUN. The body may be breaking down muscle tissue for energy because it’s not processing protein properly.

What Can You Do About High BUN in Dogs

If your dog’s BUN levels are high, your vet will likely recommend further testing to determine the underlying cause. Treatment will depend on the underlying condition but may include:

Fluid Therapy: If your dog is dehydrated, your vet might suggest giving them fluids to help them get hydrated again. It’s like giving them a special drink to make sure they have enough water in their body.

Medications: Sometimes, if there’s a problem causing your dog to feel sick, the vet might give them medicine to help them feel better. It’s like when you have a headache, and you take medicine to make it go away.

Dietary Changes: Your vet might recommend changing your dog’s food to a special kind that’s good for their kidneys. It’s like eating healthy foods when you want to feel better.

Monitoring: Your vet might want to keep an eye on your dog regularly and check their blood to see how well their kidneys are working. It’s like going to the doctor for check-ups to make sure everything is okay.


When a dog’s BUN (Blood Urea Nitrogen) levels are high, it could mean that there’s something wrong with their kidneys or other parts of their body. It’s like a signal that something might be off. To help your dog, it’s crucial to team up with your vet. Together, you can figure out what’s causing the high BUN levels and make a plan to treat it. With the right attention and care, lots of dogs with high BUN levels can still enjoy life to the fullest.

Read Also: 

Cherry Eye in Dogs

What Causes Hot Spots In Dogs?

How To Treat Mange In Dogs At Home

Confidence Building Exercises For Dogs



Hello there! I'm Madhav Mantri, the person behind this PetSavvy Solution blog. I'm a digital marketer and a pet enthusiast too! I spend my time making sure everything here is interesting and helpful for you and your pets. I love sharing cool stuff about pets, from the latest trends to heartwarming stories and useful tips to keep our furry friends happy and healthy.

Leave a Reply

Your email address will not be published. Required fields are marked *