High Levels of Protein in Dog Urine (Proteinuria in Dogs)

What Is Excess Protein in Dog Urine (Proteinuria)?

Proteinuria means there is excess protein in your dog’s urine. Although dogs usually have a small amount of protein in their urine, too much protein can be a sign of an underlying condition.

The most important condition associated with proteinuria in dogs is kidney disease, but it can also be caused by infections, inflammation or bleeding along the urinary tract, tumors, high blood pressure, and other conditions. In many cases of proteinuria that are not connected to kidney disease, the condition will resolve as soon as the underlying condition is treated.

Proteinuria caused by kidney disease is a sign that your dog’s kidneys aren’t functioning properly. Kidneys are normally responsible for filtering waste from the bloodstream and balancing levels of certain nutrients.

In dogs with kidney disease, however, a filtering structure in the kidney called the glomerulus is not working as it should. This allows proteins that would normally be kept in the blood to spill over into the urine, where they can be detected by your dog’s vet.

Proteinuria itself is not a disease—instead, it’s a sign there is an underlying condition that needs attention.

Symptoms of Proteinuria in Dogs

The symptoms of canine proteinuria depend on the underlying condition that’s causing it. In many cases, dogs with proteinuria won’t show any symptoms at all, and the condition will be discovered during a routine urinalysis at the vet’s office.

Proteinuria in dogs can be a sign of serious kidney disease, so if you see signs like lethargy or notice that your dog is drinking a lot more, you should seek out emergency veterinarian care as soon as possible.

Proteinuria in dogs may also be associated with any of the following:

• Edema (swelling) in your dog’s legs, lower chest, or abdomen. You may see pitting edema, where a dimple remains in the swollen area after you press it.

• Difficulty breathing due to fluid in your dog’s chest (pleural effusion) or abdomen (known as ascites or peritoneal effusion).

• Blood clots. Symptoms associated with blood clots include difficulty breathing, painful limbs, vomiting, diarrhea, or collapse. The exact symptoms depend on where the blood clot is located. If your dog shows any signs that may be caused by a blood clot, they need immediate emergency care.  

Causes of Proteinuria in Dogs

The causes of proteinuria include many issues that can occur anywhere along your dog’s urinary tract, including kidney disease.

• Hemolysis (when blood cells burst and release hemoglobin protein into the blood)

• Rhabdomyolysis (when muscle cells break down and release muscle protein into the blood; this can be caused by strenuous exercise, fever, or seizures)

• Infections (infection of the bladder, urethra, or ureter; genital infections; Lyme disease; anaplasmosis; ehrlichiosis; heartworm disease; dental disease; bacterial skin disease; endocarditis [infection on a heart valve]; Leishmaniasis)

• Cancers (lymphoma, mast cell tumor, multiple myeloma, transitional cell carcinoma [cancer of the urinary tract], histiocytic sarcoma)

• Inflammation caused by conditions like pancreatitis (swelling of the pancreas), inflammatory bowel disease, and arthritis

• Kidney issues (injury, failure, chronic kidney disease (CKD), cancer of the kidney)

• Fanconi syndrome (abnormal functioning of tubules in the kidneys)

• Systemic lupus erythematosus

• High blood pressure

• Cushing’s disease (hyperadrenocorticism)

• Diabetes mellitus

• Genetic predisposition

• Amyloidosis (a rare disease that causes high levels of certain proteins in the heart, kidneys, and other organs)

• Idiopathic (unknown cause)

Dog Breeds That Are Prone to Proteinuria

• Bernese Mountain Dog

• Doberman Pinscher

• Bull Terrier

• English Cocker Spaniel

• Samoyed

• Miniature Schnauzer

• Chinese Shar-Pei

• Soft Coated Wheaten Terrier

• English Foxhound

• Belgian Malinois

• Bullmastiff

• Norwegian Elkhound

How Vets Diagnose Proteinuria in Dogs

The most common test to detect proteinuria in dogs is a routine urinalysis. In this test, urine is collected from your dog and assessed by a lab or in a veterinarian’s office.

If high levels of protein are detected in your dog’s urine, your vet will recommend follow-up testing with a second test called a urine protein to creatinine ratio (UPCR). The UPCR test is considered the gold standard test to measure protein levels in dogs. It will likely be conducted along with other tests to measure your dog’s kidney health. During the UPCR test, urine will be collected from your dog and analyzed in a lab to detect the exact levels of protein in the urine. This helps your vet identify what’s causing the condition.

If a UPCR shows significant proteinuria (a value greater than 0.5), your vet should confirm it by testing two additional samples of urine taken directly from your dog’s bladder with a needle. Additional testing is recommended because proteinuria in dogs can be temporary and may not require treatment.

A urine culture may need to be ordered to determine if a urinary tract infection is present, since a urinalysis can miss a urinary tract infection. A urine culture is the best way diagnose or rule out an infection, especially if a dog has proteinuria and is having symptoms that would support an infection.

Treatment for Proteinuria in Dogs

Proteinuria itself is not a condition, but it may indicate a more serious underlying health problem.

If your dog has proteinuria, your vet will first identify the underlying cause. This will likely involve additional tests, along with a detailed history of your dog’s health and any changes in their behavior. They may also prescribe medications to prevent blood clots, such as a very low dose of aspirin or clopidogrel, a blood thinner.

Once the underlying cause has been discovered, your vet can develop a treatment plan. Some of the conditions and related treatments that are linked to proteinuria include:

Kidney Disease

Proteinuria is found in dogs with kidney disease, including chronic kidney disease (CKD) and sometimes acute kidney failure. If your dog is diagnosed with kidney disease, your vet will develop a treatment plan to relieve symptoms and restore your animal’s quality of life as much as possible.

Treating kidney disease in dogs can be complex and difficult, but it usually involves regular testing to monitor kidney function and medications that reduce the pressure on the kidneys and help them function better.

Common medications include high blood pressure medications (see below) and possibly, diuretics such as furosemide or spironolactone, if edema is present. These medications reduce the amount of swelling or fluid in your dog’s chest or abdomen. Your dog may also be prescribed a special diet with low sodium, low protein, and omega-3 fatty acids.

Infections

Infections causing proteinuria, including urinary tract infections, are often treated with antibiotics. The proteinuria often goes away after successful treatment.

High Blood Pressure

Elevated blood pressure can cause proteinuria in dogs by forcing protein into the urine in the kidneys. Common medications used to treat high blood pressure in dogs include amlodipine and telmisartan. Your vet may also prescribe ACE inhibitor medications including enalapril or benazepril.

Multiple Myeloma

Multiple myelomas are tumors that produce antibodies. They also produce special Bence-Jones proteins that are small enough to pass through the kidney’s filter and into the urine. These proteins cause proteinuria and can damage the kidney. A special Bence-Jones protein test can detect these proteins if your veterinarian suspects your dog has multiple myeloma.

Recovery and Management of Proteinuria in Dogs

Resolving proteinuria means treating the underlying condition. It’s best to detect proteinuria as early as possible so your vet can figure out what’s causing it and develop a treatment plan. In some cases, such as lower urinary tract infection, the condition can be treated relatively easily and the proteinuria will go away.

Chronic causes of proteinuria, such as inflammatory bowel disease, Cushing’s disease, or diabetes mellitus, may require long-term treatment. During treatment, your vet will try to stabilize the disease and prevent long-term kidney damage.

Dogs diagnosed with severe kidney disease, such as severe inherited kidney disorder, cancer in the kidney, or kidney failure, may not be able to stabilize the disease or will only be able to do so for a short time.