What Causes Bladder Stones in Dogs?

Bladder stones are one of those urinary problems that can catch dog owners off guard. Your dog might seem perfectly healthy one day, then start asking to go outside more often, straining to urinate, or passing urine with a pink or reddish tint.

So, what causes bladder stones in dogs?

The answer depends on the type of stone. Some develop because of bacterial urinary tract infections, while others are associated with genetics, abnormal mineral metabolism, concentrated urine, diet, or underlying medical conditions. In many cases, several factors work together.

Understanding the cause matters because different stones require different treatments. A diet that helps dissolve one type may not work for another, and some stones cannot be dissolved with food at all.

This guide explains how canine bladder stones form, the main causes and risk factors, which dogs are more susceptible, and what you can do to help prevent them. It also explains when urinary symptoms require immediate veterinary attention.

Important: If your dog repeatedly tries to urinate but produces little or no urine, seek emergency veterinary care. A urinary blockage can become life-threatening.

What Are Bladder Stones in Dogs?

What are canine bladder stones?

Bladder stones are hard mineral formations that develop inside a dog’s urinary bladder. Veterinarians call them uroliths, cystic calculi, or bladder calculi.

They can range from tiny, sand-like particles to larger, solid formations. Some dogs develop one stone, while others have multiple stones at the same time.

Stones may consist primarily of struvite, calcium oxalate, urate, cystine, or other mineral compounds. Their composition determines, in part, why they formed and which treatment is appropriate.

What do uroliths and urinary calculi mean?

You may encounter several medical terms when researching your dog’s condition:

• Bladder stones: The common term for stones inside the bladder.
• Uroliths: Stones that form anywhere in the urinary tract.
• Cystoliths: Stones specifically located in the bladder.
• Urolithiasis: The condition of having urinary stones.
• Nephroliths: Stones located in the kidneys.
• Urethroliths: Stones located in the urethra.

Although the terminology can sound complicated, these words describe stones according to their location or the condition they cause.

How do bladder stones form?

Stone formation usually begins at a microscopic level.

Dog urine contains dissolved minerals and other substances. When certain substances become concentrated enough, or when urine chemistry favors crystallization, tiny crystals may begin to form.

Those crystals can combine with other crystals, cellular debris, or inflammatory material. If conditions allow them to grow, they may eventually become solid stones.

The process generally involves:

1. Supersaturation: Urine contains a high enough concentration of stone-forming substances.
2. Crystal formation: Microscopic mineral crystals develop.
3. Aggregation: Crystals may join together or attach to other material.
4. Growth: Additional mineral material accumulates.
5. Stone formation: The growing mass becomes a urinary stone.

Crystals versus bladder stones

Urinary crystals and bladder stones are related, but they are not the same thing.

Finding crystals in a urine sample does not automatically mean your dog has bladder stones. Likewise, a dog can have stones without crystals appearing in the particular urine sample examined.

Veterinarians interpret these findings alongside the dog’s symptoms, medical history, and imaging results.

What Are the Main Causes of Bladder Stones in Dogs?

There is no single explanation for every case of canine bladder stones. The major causes and contributing factors include urinary tract infections, abnormal urine chemistry, genetics, metabolic disorders, diet, and concentrated urine.

1. Urinary tract infections

A urinary tract infection (UTI) is an especially important cause of struvite bladder stones in dogs.

Certain bacteria produce an enzyme called urease. This enzyme breaks down urea in urine, creating substances that make the urine more alkaline. The resulting chemical changes encourage struvite crystals to form.

Common urease-producing bacteria associated with infection-induced struvite stones include certain Staphylococcus and Proteus species.

The process can look like this:

Bacterial infection → altered urine chemistry → struvite crystal formation → possible stone growth

However, not every dog with a UTI develops bladder stones, and not every bladder stone is caused by an infection.

If your dog has recurrent urinary infections, your veterinarian may recommend a urine culture and imaging to investigate whether stones or another urinary problem are contributing to the recurrence. <Cite refs={[“turn707217search0″,”turn707217search1”]}/>

2. Abnormal urine pH

Urine pH describes how acidic or alkaline urine is. It can influence whether certain minerals remain dissolved or begin forming crystals.

Different stone types develop under different chemical conditions.

• Struvite stones: In dogs, these are commonly associated with urease-producing bacterial infections and alkaline urine.
• Calcium oxalate stones: Their formation involves different factors, including urinary calcium and oxalate concentrations, genetics, and other metabolic influences.
• Urate stones: These are associated with abnormal purine metabolism or certain liver-related abnormalities.

Urine pH alone cannot confirm the type of stone your dog has. It is one piece of the diagnostic picture.

Do not try to change your dog’s urine pH with supplements or home remedies without veterinary guidance. An approach that benefits one type of stone may be inappropriate for another.

3. Concentrated urine and inadequate hydration

Concentrated urine can increase the concentration of substances involved in crystal formation.

When a dog consumes too little water or loses more fluid than it takes in, its urine may become more concentrated. In a susceptible dog, this can contribute to an environment that favors certain stones.

Factors that may affect hydration include:

• Limited access to fresh water.
• Hot weather and increased panting.
• Heavy exercise.
• Illness that reduces drinking.
• Eating food with relatively little moisture.
• Certain medical conditions or medications.

Adequate hydration is useful for many dogs at risk of urinary stones, but it is not a complete prevention strategy. Genetics, infections, and metabolic conditions can still contribute.

4. Diet and mineral intake

Diet can influence urine volume, pH, and the amounts of certain minerals and other substances excreted in urine.

Depending on the stone type, relevant dietary factors may include calcium, phosphorus, magnesium, protein, purines, and overall water intake.

However, ordinary commercial dog food is not the universal cause of bladder stones. Many dogs eat the same food without developing stones, while others develop stones because of genetic or medical factors.

The appropriate nutritional approach depends on the actual stone composition.

For example, a veterinary therapeutic diet may help dissolve certain struvite stones. Calcium oxalate stones, however, generally cannot be dissolved by changing the diet.

Avoid drastically restricting minerals or changing your dog’s food based on a suspected stone type. A veterinarian should help select an appropriate diet.

5. Genetic predisposition

Some dogs inherit characteristics that make particular urinary stones more likely.

Genetic factors can influence how the body processes and eliminates substances such as uric acid or cystine. When these substances occur in unusually high concentrations in urine, the risk of certain stones may increase.

Genetic predisposition does not mean a dog will definitely develop bladder stones. It means that its baseline risk may be higher and that prevention may need to be tailored accordingly.

6. Metabolic diseases

Some medical conditions alter the way the body handles calcium and other substances.

For example, elevated blood calcium can contribute to increased urinary calcium in some dogs, potentially increasing the risk of calcium oxalate stones.

When these stones are diagnosed, veterinarians may investigate potentially treatable contributors, including hypercalcemia, primary hyperparathyroidism, or hyperadrenocorticism, depending on the dog’s history and test results.

Other metabolic disorders may influence different types of stones.

7. Liver abnormalities and portosystemic shunts

The liver plays an important role in processing substances that the body eventually eliminates through urine.

A portosystemic shunt is an abnormal blood vessel that allows some blood to bypass the liver. This can interfere with normal metabolism and increase the risk of urate stones.

Urate stones may also occur in dogs with inherited abnormalities in uric acid metabolism, particularly certain breeds such as Dalmatians.

If a dog develops urate stones, its veterinarian may recommend evaluating liver function and considering inherited metabolic factors. <Cite refs={[“turn707217search2″,”turn707217search0”]}/>

8. Medications and other urinary abnormalities

Certain medications or supplements may affect urinary chemistry or mineral handling. The significance depends on the substance, dose, duration, and the dog’s underlying health.

Bladder inflammation and other urinary tract abnormalities can also contribute to stone formation in some cases.

Tell your veterinarian about every medication, supplement, and urinary health product your dog receives. Do not stop a prescribed medication without professional advice.

Types of Bladder Stones in Dogs and Their Causes

Identifying the stone type is essential because the causes, treatments, and prevention strategies differ.

Which Dog Breeds Are More Prone to Bladder Stones?

Any dog can develop bladder stones, but some breeds are more frequently associated with particular stone types.

These associations do not mean every dog of a particular breed will develop stones. Nor does breed alone identify the type of stone present.

A dog’s age, sex, symptoms, medical history, urine tests, and imaging results are all important.

Are Male or Female Dogs More Likely to Get Bladder Stones?

The answer depends partly on the type of stone and the underlying cause.

Female dogs are often represented among dogs with infection-associated struvite stones because urinary tract infections are relatively common in females.

Male dogs, however, have an important anatomical disadvantage when it comes to obstruction. Their urethra is longer and narrower, making it easier for a stone to become lodged as it leaves the bladder.

This distinction matters because a stone that causes irritation in one dog could cause a dangerous blockage in another.

If your male or female dog is repeatedly straining without producing urine, seek emergency veterinary care.

What Are the Symptoms of Bladder Stones in Dogs?

Some dogs develop obvious symptoms, while others have stones discovered during an examination for another problem.

Common signs include:

• Blood in the urine, which may appear pink, red, or brown.
• Frequent urination, often with small amounts of urine.
• Straining to urinate or taking longer than usual.
• Pain or discomfort while urinating.
• Urinary accidents in a normally house-trained dog.
• Excessive licking around the genital area.
• Changes in urine appearance.
• Recurrent urinary tract infections.

These signs are not specific to bladder stones. UTIs, bladder inflammation, and other urinary problems can cause similar symptoms.

A veterinary examination is needed to identify the cause.

Can bladder stones cause a urinary blockage?

Yes. This is one of the most serious complications.

A stone may move from the bladder into the urethra and become lodged. A partial blockage may allow small amounts of urine to pass, while a complete blockage prevents normal urination.

Warning signs include:

• Repeated attempts to urinate with little or no urine.
• Obvious discomfort or abdominal pain.
• Restlessness.
• Vomiting.
• Weakness or severe lethargy.
• Collapse in advanced cases.

A dog that cannot urinate needs immediate emergency veterinary attention. Do not wait overnight, try home remedies, or press on the abdomen.

How Are Bladder Stones Diagnosed?

Veterinarians use several tests to identify stones and investigate their likely causes.

Urinalysis

A urine sample can provide information about urine concentration, pH, blood, inflammatory cells, bacteria, and crystals.

However, finding crystals does not prove that a stone is present.

Urine culture

A urine culture helps determine whether bacteria are causing an infection and, when appropriate, which antibiotics are likely to be effective.

It is particularly important when infection-associated struvite stones are suspected.

X-rays and ultrasound

Abdominal X-rays can detect many bladder stones. Ultrasound can help identify stones that are difficult to see on ordinary radiographs and can provide information about the bladder wall and other urinary structures.

Some stones are less visible on standard X-rays, so the veterinarian may recommend additional imaging when necessary.

Blood tests

Bloodwork may help evaluate kidney function, calcium levels, liver function, electrolytes, and other abnormalities that could contribute to stone formation.

Stone analysis

If a stone is removed, laboratory analysis can identify its mineral composition.

This is one of the most useful steps for developing a prevention plan because treatment should be based on the stone type rather than guesswork.

Can Bladder Stones Be Dissolved or Do They Need Surgery?

Treatment depends on the stone’s composition, size, location, and whether it is causing an obstruction.

Medical dissolution

Some struvite stones can be dissolved using a veterinary therapeutic diet. When the stones are associated with a bacterial infection, appropriate antimicrobial treatment is also necessary.

The veterinarian monitors progress with follow-up examinations and imaging. Dissolution can take weeks or longer, and the approach is not appropriate for every dog.

Surgical or minimally invasive removal

Calcium oxalate stones generally cannot be dissolved medically. They may need to be removed surgically or through an appropriate minimally invasive procedure.

Depending on the case and local availability, options can include:

• Cystotomy: Surgery to open the bladder and remove stones.
• Cystoscopy: Using a small camera to locate and remove suitable stones.
• Urohydropropulsion: Flushing out appropriately small stones under veterinary supervision.
• Laser lithotripsy: Breaking stones into smaller fragments for removal.

If a stone is blocking urine flow, relieving the obstruction takes priority. Treatment should not be delayed while waiting to see whether a stone might dissolve.

How Can You Prevent Bladder Stones in Dogs?

Prevention depends on the cause, but several practical steps can support urinary health.

1. Encourage adequate water intake

Provide fresh water throughout the day. Some dogs drink more readily when they have multiple water bowls or a fountain.

Adding water to meals or feeding suitable moisture-rich food may also help increase total fluid intake.

Ask your veterinarian about an appropriate hydration strategy if your dog has a history of stones or another medical condition.

2. Choose the right diet

Do not choose a urinary diet simply because the package says it supports urinary health.

A dog with struvite stones may need a different dietary approach from a dog with calcium oxalate or urate stones. Ask your veterinarian which food is appropriate and whether treats or supplements could interfere with the plan.

3. Treat urinary tract infections properly

If your dog has recurrent UTIs, follow the recommended diagnostic and treatment plan. In some cases, follow-up urine cultures help determine whether infection has resolved or returned.

4. Investigate underlying disease

Dogs with recurrent stones may need additional testing for metabolic or liver-related abnormalities.

Addressing an underlying problem can be an important part of reducing recurrence.

5. Keep follow-up appointments

A dog that has already developed bladder stones may need repeat urinalysis, urine cultures, X-rays, or ultrasound examinations.

The recommended schedule depends on the stone type, treatment, and individual risk.

6. Do not use home remedies to alter urine pH

Apple cider vinegar, urinary supplements, and other home remedies cannot reliably treat every type of stone.

Changing urine chemistry without knowing the stone type may be counterproductive. Discuss any proposed supplement or dietary change with your veterinarian.

Frequently Asked Questions

What is the most common cause of bladder stones in dogs?

There is no single cause for all bladder stones. Infection-associated struvite stones are common in dogs, while calcium oxalate stones are also among the most frequently diagnosed. Genetics, urine chemistry, and metabolic conditions can contribute to other types.

Can dry dog food cause bladder stones?

Dry food is not automatically the cause. Diet and water intake can influence urinary chemistry, but infections, genetics, and medical conditions can also play important roles.

Can dehydration cause bladder stones?

Dehydration can contribute to concentrated urine, which may favor crystal formation. However, it does not explain every case, and adequate water intake cannot eliminate all stone risks.

Can a UTI cause bladder stones?

Yes. Certain urease-producing bacteria alter urine chemistry in a way that favors struvite stone formation.

Do bladder stones cause blood in the urine?

They can. Stones may irritate the bladder lining and cause bleeding, although blood in the urine can also result from other urinary conditions.

Can bladder stones disappear on their own?

Some very small stones may pass, but this is not something to rely on. A stone can become lodged in the urethra, causing a dangerous blockage. Have suspected stones assessed by a veterinarian.

Can bladder stones return after surgery?

Yes. Removing a stone does not necessarily eliminate the underlying cause. Stone analysis, appropriate nutrition, treatment of contributing conditions, and follow-up monitoring can help reduce the risk of recurrence.

What should a dog with bladder stones eat?

The right diet depends on the stone’s composition and the dog’s medical condition. Some struvite stones can be dissolved using a veterinary therapeutic diet, while calcium oxalate stones generally require removal when treatment is necessary.

Are bladder stones painful for dogs?

They can cause significant discomfort, particularly when they irritate the bladder or interfere with urination.

When should I take my dog to the vet?

Arrange a veterinary appointment for blood in the urine, frequent urination, straining, painful urination, or recurrent urinary infections. If your dog cannot urinate or repeatedly strains without producing urine, seek emergency care immediately.

Final Thoughts

Bladder stones in dogs develop when mineral or other substances form crystals and grow into solid formations inside the urinary tract. The underlying causes vary: urinary tract infections, abnormal urine chemistry, concentrated urine, diet, genetics, and metabolic or liver-related conditions can all play a role.

The most important step is to determine which type of stone your dog has. That information helps your veterinarian choose an appropriate treatment and build a prevention plan that fits your dog’s needs.

At home, you can support urinary health by providing fresh water, following appropriate dietary advice, and keeping up with veterinary follow-up appointments. But do not attempt to dissolve stones or change urine pH without professional guidance.

Finally, pay attention to changes in your dog’s urination. Blood in the urine, repeated straining, or frequent attempts to urinate deserve veterinary attention. If no urine is coming out, treat it as an emergency.