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Why Does My Dog’s Urine Smell Like Ammonia?

Have you noticed a change in the smell of your dog’s urine? A strong ammonia smell could be a symptom of a health problem, particularly if it smells stronger than normal.

A sudden change in your dog’s toileting habits can signal an underlying problem, including if their urine smells more strongly of ammonia.

These changes aren’t always something to worry about. For example, urine gradually smells stronger if it dries in carpet fibres, as the ammonia converts into mercaptan gas. But there can be occasions when a strong urine smell indicates a potentially significant problem.

Urinary tract infections, bladder stones and diabetes, for example, are serious conditions that can produce changes in a dog’s urine – including a strong ammonia smell.

If you notice any changes, especially combined with unusual behavior or other symptoms, you should always seek prompt veterinary advice.

It’s not uncommon for owners to develop an unnatural obsession with their dog’s daily toileting routines – and that’s not a bad thing! The sooner you notice changes and take action, the more likely treatment is to be successful.

Here’s an overview of why your dog’s urine may smell like ammonia, and what it could mean for his health.

What Are The Characteristics of Healthy Canine Urine?

There are three main elements that determine if your dog is passing ‘normal’ urine: color, quantity and smell.


Just like humans, clear urine usually indicates that a dog is well-hydrated.

Sometimes, though, clear excretions can be a sign that your dog isn’t able to manage their urine concentration levels effectively. If they are not drinking much, but still have very clear urine, then perhaps a trip to the vet is required.

Alternatively, clear urine may be a sign that the dog is drinking too much, which is also a reason for a vet visit. “When an owner comes to me worried about clear urine, I usually find their dog is drinking to excess,” says vet Dr Linda Simon. “This is known as PU/PD (excessive thirst, excessive urination) which can have a range of causes including diabetes and chronic renal disease.”

At the other end of the spectrum, dark urine may indicate an issue. The darker the shade of yellow, the less hydrated your pet is, and you should try to encourage them to take in more fluids.

If your dog’s urine looks orange, brown or red, this is a red flag and could signal internal bleeding. It may not always be something serious, but is certainly something you should speak with your vet about.

Cloudy urine can also be an indicator of a problem, often bladder stones, and it should not be ignored.


If your dog suddenly needs to potty more frequently, or the amount that they are producing is significantly more or less than normal, this could warrant a trip to the vet.

Frequency can be impacted by several factors including blockages, medical conditions and infections.


A sudden change in the smell of your dog’s urine can also be a warning that something else is going on.

If your dog’s urine is more concentrated, it will smell stronger (often of ammonia). Specific conditions or medical problems can also lead to an unpleasant or strong smell.

What Causes Dog Urine to Smell Like Ammonia?

A cavalier peeing

Highly concentrated urine can often take on an overpowering, almost chemical-like, ammonia smell.

Urea is one of the waste products found in urine. It is produced when the body naturally metabolizes proteins. The liver converts toxic ammonia created by the breakdown of amino acids into this less toxic substance.

If your dog’s urine suddenly starts to smell stronger, it can often indicate a urinary tract infection. In rarer cases, it could be caused by an issue with the metabolization process or the conversion of ammonia in your dog’s system.

“Usually, strong-smelling urine is something an owner notices when their dog has a urine infection,” says vet Dr Linda Simon. “So, if an owner tells me the urine is suddenly smelly, I will frequently perform a urine culture, to check for infection.”

Whatever the reason, you should always contact a vet if your dog’s urine smells strongly of ammonia. It’s important to rule out serious medical causes.

4 Health Reasons Why Your Dog’s Pee Smells Strongly of Ammonia

Changes in toileting habits can be caused by a variety of health conditions. Here are four of the most common reasons for urine smelling like ammonia.

1. Urinary Tract Infection

UTIs are relatively common in our four-legged friends. As much as 14% of the doggy population could develop a UTI at some point in their life, and it can be caused by various underlying issues.

“Some of the more common underlying causes of UTIs I encounter include diabetes, bladder stones, and bladder masses. I see them more often in puppies and seniors,” says vet Dr Linda Simon.

UTIs are relatively simple to treat but, if left too long, they can spiral out of control. They can also be a sign of a more serious underlying condition, especially if they are recurring.

A dog with a UTI will often have a foul-smelling urine odor, and they may show discomfort urinating. Other symptoms include blood in the urine, a cloudy or unusually dark color, a desire to go potty more often, obsessive licking of the genital region, and possibly a fever.

Most UTIs can be treated with a course of antibiotics. Sometimes your vet will perform further tests, such as bladder ultrasounds or a urine culture, as UTIs can also be a sign of other conditions like bladder stones, or kidney or prostate problems.

2. Dehydration

If your dog is not drinking enough fluids, particularly in warm weather or after exertion, this can lead to urine becoming more concentrated and odorous. In this case, the strong ammonia smell will be accompanied by darker urine. Vomiting and diarrhea can also lead to dehydration.

Unfortunately, some dogs are unwilling to drink more water. If you struggle to get your dog to drink directly from a bowl, you could mix it in with their food to ensure they get a greater intake.

Dehydration can also be caused by certain medications and health conditions, like kidney disease or diabetes. Signs of dehydration include skin losing elasticity, lethargy and a loss of appetite.

3. Kidney Disease

Chronic kidney disease is another condition that is more common than you might think in dogs, particularly in senior canines.  One of the earliest signs is that your dog needs to urinate more frequently. They may also start having accidents in the house.

At first, this condition generally leads to more diluted urine, which smells less strongly of ammonia. However, as it progresses, dogs with kidney disease often begin to pass urine that smells stronger (due to toxin build-up and increased ammonia), and can even have a pungent ammonia smell to their breath.

Kidney disease often goes undetected in the early stages, but this is when treatment would prove the most beneficial. If you notice your dog drinking more and having accidents, don’t just restrict their water to try and minimize this – take him to the vet.

4. Bladder Stones

Bladder stones can often lead to UTIs, and they can present with similar symptoms, including foul-smelling urine.

The crystals that form uncomfortable bladder stones can be treated with a specially formulated diet, usually one low in purines. A course of antibiotics may also be needed to treat any infections associated with the crystals. There are different types of bladder stones, however, so the treatment will depend on which type the vet discovers your dog has.

Bladder stones, called Struvites, can occur as a result of a UTI too.  Others develop as a result of insufficient water intake, a poor diet, or even a genetic predisposition.

Ensuring your dog gets a high-quality diet with the right balance of nutrients can be important in minimizing the chance of developing this painful condition.

How to Eliminate a Urine Ammonia Smell in the House

Removing pee odors from the carpet

If your dog has an accident in the house, the urine smell and stains can be hard to eliminate.

The uric acid crystals usually aren’t fully lifted when using standard cleaning products. They are not water-soluble and are very persistent, latching onto a myriad of surfaces and fibres.

We recommend using a pet-friendly stain and odor removing product. Ideally, this should contain active enzymes that break down the uric acid molecules and lift the stain and smell.

If pet urine is left too long, however, it can cause stains on carpets that you may never manage to eradicate completely. Try to clean up urine stains as quickly as possible to prevent lasting discolouration.

If you don’t have an enzymatic cleaner, using a solution of water and vinegar can be a safe alternative (test on a small patch first.) Once this has been blotted and dried, using some bicarbonate of soda to neutralize the odors can be helpful.

Tip: Are you struggling to remove an old stain from carpets or wooden floors? Consider trying an enzymatic stain cleaner. You may also want to read our guide to how to get rid of dog smells in the home.


Strong smelling dog urine is not necessarily a sign of something ominous – but it shouldn’t be ignored.

A dog’s urine smelling of ammonia can be caused by serious conditions, such as kidney disease, UTIs and dehydration, so you should always contact a vet if you notice any changes in your dog’s urine.


Gemma Johnstone

Gemma is a freelance writer and official dog nut. With 15 years of experience in the pet industry, she is a passionate animal welfare advocate. She has worked for the Scottish Society for the Prevention of Cruelty to Animals, ran her own specialist dog shop for ten years, has volunteered for her local rescue shelter, and is studying towards completing an Advanced Diploma in Canine Behaviour. Gemma is currently travelling around Europe with her wonderful rescue dog, Annie.

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