Mucus In Dog Urine

Being a pet parent is a great responsibility. You have to be mindful of your pet’s health in various aspects. Finding mucus in your dog’s urine can be worrisome because you don’t know what it means.

It could be the symptom of an infection or because your dog is in heat. Healthy dogs have clear or slightly yellow urine with no traces of mucus, pus, or blood. if you notice anything unusual about your dog’s urine, you should not dismiss it. Consult your veterinarian as soon as possible.

Keep reading to learn more about why your dog could have mucus in his urine.

The Canine Urinary Tract

A dog’s urinary system is very similar to humans. The kidney creates urine, which flows down to the bladder through two tubes called ureters. The bladder is an organ present at the back of the abdomen which holds urine and expands as it fills up. The urine leaves the body through the urethra. The urethra is present above the vagina in female dogs and within the penis in male dogs.

Due to their anatomy, female dogs have a higher risk of developing Urinary Tract Infections (UTIs). Since the urethra is close to the vaginal and rectal areas which contain a host of bacteria, the bacteria can travel into the urinary tract and cause infections.

What is Mucus?

Mucus is a slimy, gelatinous fluid that the body produces to moisturize, protect, or clean certain parts of the body. Organs such as the nose, lungs, and stomach have a layer of membranes that produce mucus. It naturally protects the body from foreign objects such as dust, debris, or harmful substances. When you breathe, allergens and dust stick to the mucus and are coughed up. If your dog has mucus in his urine, it could mean many things.

Causes of Mucus in Dog Urine

If you notice mucus in your dog’s urine, it could indicate the following:

Bladder Infection

Cystitis is the inflammation of the bladder which can occur due to many reasons. The lining of the bladder becomes inflamed due to an infection, injury, medications, or other illnesses. While bacterial bladder infections can occur in male dogs, they occur the most in female dogs. Bladder infections are painful, uncomfortable, and have many symptoms other than mucus in the urine. If your dog has a bladder infection, you will notice that urinating is difficult for your pet.

A bladder infection presents as difficulties urinating, whimpering while urinating, straining, cloudy urine, incontinence, and increased thirst. If the infection is severe, it can also cause fever and weakness. If you notice the above symptoms along with mucus in urine, consult your veterinarian as soon as possible. At times, bladder infections can clear up at home if they are mild. However, treatment for a severe infection involves antibiotics and anti-inflammatory medication.

Bladder Stones

Bladder stones are small stones that are present in the bladder. They consist of minerals and are more common than kidney stones in dogs. Your dog could have single or multiple stones in his bladder. These stones are sharp and rough so they can cause inflammation in the bladder when they brush up against the lining.

Although the kidneys and bladder are connected, bladder stones are not similar to kidney stones. Recent studies show that diets that cause highly acidic urine can put dogs at risk for developing bladder stones. Chemicals such as calcium, citrates, and oxalates in the urine can also cause bladder stones.

The symptoms of bladder stones are similar to bladder infections, but they can also cause bloody urine. The stones can cause internal bleeding by harming the lining of the bladder. Larger stones can even obstruct urine, causing the bladder to rupture.

Urinary Tract Infection (UTIs)

Urinary Tract Infections (UTIs) are infections of the urinary tract. Unlike bladder infections where the bacteria has made its way to the bladder, the bacteria is present in the urinary tract. A UTI can also lead to bladder infections if left unrelated. Female dogs have a higher rate of Urinary Tract Infections in comparison to male dogs. The common cause for UTIs is E. coli bacteria which is present in feces. However, other bacteria can also cause an infection.

The symptoms of a UTI are very similar to a bladder infection, so consult your veterinarian to confirm whether it is a UTI or a bladder infection. Dogs with health issues such as Diabetes, kidney disease, and Cushing’s disease have a higher risk of developing UTIs. Unlike humans, a dog suffering from a UTI sometimes might show no symptoms. It is important to regularly visit your veterinarian so you can detect such illnesses.


Vaginitis is the inflammation of the vagina in female dogs. It can be caused by a variety of factors such as infections or injury. Some dogs also develop vaginitis which resolves after their first heat cycle. However, vaginitis can occur at any age in dogs that are spayed or unspayed. The common symptoms of vaginitis include inflammation in the vaginal area, discharge such as mucus, and licking of the vaginal area. To diagnose vaginitis in your dog, your veterinarian will run some tests, and evaluate symptoms and medical history.

In most cases, vaginitis is easy to treat and most dogs recover fully in two to three weeks. Treatment options vary based on the cause of the inflammation. For most dogs, antibiotics and daily vaginal douching are enough to treat the condition. If your dog is an adult, spaying can reduce the risk of vaginitis. In some cases, treatment may involve surgery.


Pyometra is a condition that occurs in unspayed female dogs. The uterus can become infected, which also causes mucus in the urine. Pyometra is a life-threatening condition that commonly occurs after a heat cycle in older, unspayed dogs. During heat cycles, the uterine lining thickens. This process is similar to the thickening of the uterine lining in humans during the menstrual cycle. As the lining thickens, it becomes difficult for the uterus to contract and push out fluids. Female dogs who undergo frequent heat cycles can develop an infection in the uterus.

The symptoms of Pyometra vary based on whether the cervix (the tube that leads from the uterus to the vagina) is open or closed. If it is open, you will notice a foul-smelling mucus-like discharge. If not, the infection can build within the body and infect surrounding organs. When left untreated, Pyometra can lead to death.

Yeast Infection

Another common reason to find mucus in your dog’s urine could be a yeast infection. Yeast infections occur due to the presence of Candida yeast, which is normally present on the skin and in the body of dogs. However, when there is an overgrowth of the yeast, it can cause a fungal infection. Dogs that take antibiotics or corticosteroids for a prolonged period, or those with diabetes are at risk for developing a yeast infection. Antibiotics can also kill the healthy bacteria in the body, leading to a yeast infection.

Dogs suffering from a yeast infection in the lower urinary tract can show symptoms such as mucus in urine, lethargy, nausea, difficulty and pain when urinating, and incontinence. Since the symptoms are similar to a bacterial infection, your veterinarian can determine the cause of the infection using tests such as urinalysis. Treatment involves antifungal medication and probiotic supplements.

Estrus Cycle

At times, what appears as mucus in the urine can simply be vaginal discharge. Female dogs that in their estrus or heat cycle can produce vaginal discharge that is mucoid or bloody. It can be difficult to tell if the mucus is present in the urine or secreted by the vulva since the two openings are close together. However, if your dog is unspayed and has been in heat, the mucus in her urine could just be vaginal discharge.

If you want to be sure, monitor your dog for other signs of a urinary or bladder infection. Dogs at the end of their heat cycle generally produce some amount of vaginal discharge. If the discharge is clear or mucus-like, there is nothing to worry about. However, if you notice bloody discharge or pus, contact your veterinarian immediately.

The sudden appearance of discharge when your dog is not in heat could also be worrisome. In any case, your veterinarian can provide a definitive diagnosis.

Sexually Transmitted Diseases (STDs)

Like humans, dogs can develop Sexually Transmitted Diseases (STDs) such as Herpes and Brucellosis. Breeding populations are susceptible to developing STDs, but these are rare in dogs. You can consider that your pet may have an STD if they have recently mated and symptoms arose after the event. If they haven’t, bladder and urinary infections can present similar symptoms so you should visit your veterinarian for a confirmed diagnosis. Dogs with STDs can experience inflammation in the genital area which can be very painful.

Most canine STDs are readily treated using antibiotics but require prompt treatment. If left untreated, the disease poses many risks to your pet’s general health. The infection can spread to other parts of the body without treatment.

The three most common STDs that affect dogs include:


Canine Herpesvirus

Canine Transmissible Venereal Tumor

These diseases are rare in spayed and neutered dogs. They generally affect breeding populations and unspayed dogs that mate with stray, wild, or feral dogs.

What You Can Do

Finding mucus in your dog’s urine is never a good sign and you should take your pet to the veterinarian as soon as possible. Some conditions can also be life-threatening if left untreated. The best course of action is prompt diagnosis and treatment. If your dog is not spayed or neutered, you should consider having them spayed or neutered. A major cause of mucoid discharge in your pet’s urine is issues related to the reproductive system.

If your dog has successfully recovered from a bacterial or fungal infection of the bladder or urinary tract, you should take some preventive measures for the future. Ensuring your pet stays hydrated and feeding them a diet with probiotics can prevent infections in the future. A healthy and balanced diet with the right amount of minerals can prevent bladder stones in the future.

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