Particles in the Urine in Dogs

Many diseases can be diagnosed by urinalysis, especially those that limit kidney function. Microscopic analysis of urine samples can detect particles called casts. These are cylindrically shaped proteins, called mucoproteins, which can contain different types of cells. A small number of casts in the urine is normal, but a high concentration is called cylindruria and it suggests that something is causing a problem with the kidneys, whether direct kidney failure or a systemic problem that affects the kidneys. The types of cells contained in the casts can sometimes help to determine the cause. Casts must be detected within two hours or they will dissolve; additionally diluted urine, or urine that has a low specific gravity, may dissolve the casts faster and make them harder to detect. Cylindruria may be a sign of many conditions such as poisoning, long-term kidney failure, or bacterial infection. It often occurs with congestive heart failure and conditions of excessive blood coagulation because these conditions limit blood flow in the kidneys. Although cylindruria is not a conclusive finding, combined with other laboratory tests and a thorough evaluation of your dog’s symptoms, cast identification can help the veterinarian make an accurate diagnosis.

Urine testing is a common way for veterinarians to diagnosis diseases in dogs. If high numbers of particles, or casts, are found in the urine, this is called cylindruria. It is usually indicative of kidney failure or a systemic disease that is affecting the kidneys.

Symptoms of Particles in the Urine in Dogs

Cylindruria could be present with a number of different symptoms depending on the cause. It could also be a cause for concern if found on a normal exam with no symptoms. These are some of the signs you might see in your dog with conditions that can cause kidney failure. Life-threatening symptoms (such as poisoning) should be treated as an emergency.

• Excessive drinking
• Frequent urination
• Vomiting
• Diarrhea
• Weight loss
• Poor appetite
• Lethargy
• Lack of stamina
• Weakness
• Reduced urine output
• Signs of abdominal pain
• Fever or other symptoms of infection
• Irregular heartbeat
• Seizures or poor muscle coordination
• Excessive salivation
• Shock or coma

Types

These are some of the different types of casts and what they might signify.

• Hyaline casts - some hyaline casts are normal, but excessive amounts suggest dehydration; this could be caused by fever, excessive exercise, or renal disease
• Waxy casts or granular casts –some of these types are normal, but high amounts indicate renal tubular disease
• RBC casts (red blood cell) –suggests bleeding caused by severe renal disease, hemorrhage into the kidneys, or high blood coagulation levels
• WBC casts (white blood cell cases) –usually a sign of kidney inflammation, often caused by urinary tract infection
• Fatty casts –uncommon, but they may suggest diabetes

These are some of the conditions that could be associated with particles in the urine.

• Severe dehydration
• Poisoning by a substance that affects the kidneys (ethylene glycol, grapes or raisins, NSAID’s, ACE-Inhibitors)
• Drug toxicity (Gentamicin which is an antibiotic, Amphotericin B. which is an anti-fungal medication)
• Chronic kidney disease
• Kidney cancer
• Congestive heart failure
• Endocarditis (bacterial heart infection)
• Amyloidosis – protein deposits in the kidneys; this is a hereditary condition in Chinese Shar-Peis, but it can also be caused by long term inflammation
• Pyelonephritis (acute kidney infection)
• Leptospirosis – a systemic bacterial infection that can be transferable to humans

The veterinarian will order a urine test because your dog is showing unusual symptoms or in the course of a regular exam. If your dog is unable to void normally, a catheter could be required in order to obtain a urine sample. The number of casts in your dog’s urine, as well as the type of casts present will help to show what is causing the problem. Other abnormalities may also be detectable in the urine, such as a high protein levels, abnormal acidity, blood cells or a bacterial infection. Bloodwork can help to show the degree of kidney failure, as well as blood toxicity, acidosis and blood coagulation levels.

The veterinarian will want to know your dog’s complete medical history, as well as any past or present medications, and recent exposures to toxins or infection. An accurate description of your dog’s symptoms is extremely important. Any known condition such as kidney dysfunction, diabetes, or  hereditary abnormalities is also relevant. If the problem remains unidentifiable, a kidney biopsy could be necessary.

Treatment will focus on keeping your dog hydrated. Fluids and electrolytes can help dilute the urine and reduce toxicity levels. In mild cases, dehydration could be the only problem. If your dog is unable to drink properly, fluids may need to be administered intravenously. This is important with poisoning as well as kidney failure from leptospirosis. Antibiotics may be prescribed to deal with a bacterial infection. For poisoning, activated charcoal is often given to reduce absorption.

Adequate fluids can also help decrease blood toxicity and reduce hyper-coagulation. Blood thinners may also need to be prescribed and in severe cases your dog might need blood transfusions or additional oxygen.

Chronic kidney disease is primarily managed with a diet change to reduce stress on the kidneys and extra fluids. Depending on what stage the disease is in, other medications could be prescribed. The veterinarian might recommend dialysis to prolong your dog’s life. Kidney cancer could require surgery, or chemotherapy to reduce metastasis.

Cylindruria without other symptoms is sometimes a sign of drug toxicity. If your dog is taking a medication that can cause kidney damage, the veterinarian might reduce the dosage or prescribe a different medication.

Recovery will depend on the condition that is causing the particles in dog’s urine. Cylindruria alone isn’t necessarily serious, but it can be indicative of many problems some of which could be life-threatening. The likelihood of recovery will be determined by a veterinarian. Your dog might need to stay on a strict diet to manage kidney deterioration. This could involve a prescribed dogfood, or the veterinarian might recommend a homemade diet. Extra fluids are always important.

Leptospirosis is a bacterial infection that can be zoonotic (transferrable to humans), so care should be taken with handling urine and any other infectious fluids if your dog is diagnosed with this condition. All infected dogs should be quarantined. Dogs can be vaccinated against the disease to help prevent infection.