Overview of Recurrent Cystitis (Bladder Infections) in Dogs
Recurrent cystitis is defined as repeated bouts of inflammation of the urinary bladder. Generally in small animal veterinary medicine, cystitis is usually synonymous with “bladder infection.”
General Causes of Recurrent Bladder Infection in Dogs
Inappropriately treated urinary tract infections
Inflammation in the urogenital tract
Neoplasia (cancer) in the urogenital tract
Metabolic disorders (kidney disease, liver disease, Cushing’s disease)
Neurologic disorders (causing retention of urine)
Urolithiasis (stones in the urinary tract)
Congenital (present at birth) urinary tract abnormalities
Parasites that affect the urinary tract
Medication (chemotherapy, corticosteroids)
Recurrent cyctitis is most common in female dogs of any age or breed. Clinical signs depend on the severity and possibly underlying cause of cystitis. Affected individuals may be asymptomatic (have no clinical signs), and infections may be picked up on routine testing.
Watch to Watch for
Signs of bladder infections in dogs may include:
Urgency to urinate
Vaginal or penal discharge
Diagnostic Tests for Recurrent Bladder Infections in Dogs
Tests may include:
Complete blood count
Urine bacterial culture and sensitivity
Abdominal radiographs (X-rays)
Contrast cystourethrogram (dye study of the lower urinary tract)
Urinary bladder biopsy and culture
Treatment of Recurrent Bladder Infections in Dogs
Treat the underlying disease if identified
Proper antibiotic therapy (type, strength, and length of administration)
Surgical intervention may be necessary in certain cases, such as stones or tumors.
Administer all medication and diet as recommended by your veterinarian.
Contact your veterinarian at once if your pet is showing clinical signs consistent with cystitis.
Follow your veterinarian’s recommendation regarding diet and medication administration, as these practices may help to prevent recurrence in the future.
In-depth Information on Recurrent Bladder Infections in Dogs
Recurrent cystitis is defined as an inflammation of the urinary bladder, although it most often refers to relapses or reinfection caused by bacteria. There may be factors that enhance the susceptibility to recurrent infections such as congenital abnormalities (structural changes that have existed from birth), metabolic disorders or systemic immunosuppression (a decrease in efficiency of the body’s immune system); however, no underlying disorder need exist. It is also important to note that administering an incorrect antibiotic, or antibiotics at too low a dose or too short a course may not fully eradicate an infection, contributing to recurrent or persistent infections.
The clinical signs associated with recurrent cystitis may be mild, or even unnoticed, although some individuals may have severe, unrelenting signs of discomfort often associated with urinating. Depending on the specific case, certain diagnostics and therapeutics would be recommended and tailored to that individual.
Several diseases/disorders can present similarly to recurrent cystitis. These include:
Urolithiasis (stones) anywhere throughout the urinary tract may be associated with cystitis. In addition to the similarity in their presentation, stones are commonly the underlying cause of recurrent cystitis.
Pyelonephritis (kidney infection) may cause or be the result of patients with recurrent cystitis.
Chronic renal (kidney) failure may be associated with, cause or be the result of recurrent cystitis.
Bacterial prostatitis (inflammation or infection of the prostate) and metritis (inflammation of the uterus) can present similarly to animals with recurrent cystitis, with hematuria (bloody urination), stranguria (straining to urinate) and pollakiuria (frequent urination).
Metabolic illnesses, such as hyperadrenocorticism (Cushing’s disease) or diabetes mellitus
Administration of medication (chemotherapy, corticosteroids), can suppress the immune system, creating an environment that favors recurrent cystitis. Additionally, cyclophosphamide, an agent used in many chemotherapeutic protocols, can cause a sterile (non-infectious) cystitis (inflammation of the bladder).
In addition to the above disorders, severe clotting (bleeding) disorders can often show signs similar to recurrent cystitis, most often with hematuria. Any bleeding disorder needs to be differentiated from recurrent cystitis. Some of the more common clotting disorders include:
Thrombocytopenia (a decrease in the number of platelets) can cause hematuria. Platelets are essential for normal clotting, and a decrease in their number is often associated with spontaneous bleeding. The urinary tract is one of many places thrombocytopenia may manifest itself.
The ingestion of rat poison (Warfarin toxicity) can cause hematuria by interfering with the normal clotting mechanism. The urinary tract is one of many places that can be associated with spontaneous bleeding.
Liver disease, including infections, inflammation and cancer, can interfere with the normal clotting mechanism, as a normal functioning liver is necessary to produce ample clotting factors.
Disseminated intravascular coagulation (DIC) can be associated with hematuria. This is an overwhelming syndrome in which spontaneous bleeding is common.
Trauma to the abdomen or external genitalia can cause bleeding in the urine. This may be due to rough housing with household pets, chewing or licking at the vulva or penus, or caused by repeat catheterizations for any reason.
Neoplasia (cancer) involving the lower urinary tract may need to be differentiated from cystitis in these patients, as slow and painful urination (stranguria), blood in the urine (hematuria) and painful urination (dysuria) are commonly seen.
Estrus (heat) can cause bloody urine due to the genitalia’s close proximity to the passage of urine.
In-depth Information on Diagnosis
Certain diagnostic tests must be performed to make a definitive diagnosis of recurrent cystitis and exclude other disease processes that may cause similar symptoms in dogs. A complete history, description of clinical signs, and thorough physical examination are all an important part of obtaining a diagnosis, and potential underlying cause. In addition, the following tests are recommended:
A complete blood count (CBC) is often within normal limits; however, an elevated white blood cell count may be present in cases with systemic infection, and mild anemia (low red blood cell count) may be present with chronic urinary bleeding.
A biochemical profile may be within normal limits, although it may reveal elevations in kidney enzymes, electrolyte abnormalities or may have other changes suggestive of other metabolic or endocrine disorders that may predispose the individual to recurrent cystitis.
A urinalysis may reveal hematuria (blood in the urine), pyuria (white blood cells in the urine), proteinuria (protein in the urine), bacteriuria (bacteria in the urine) and/or white blood cell casts. The absence of any or all of these does not rule out cystitis.
A bacterial urine culture to confirm a urinary tract infection.
Abdominal radiographs (x-rays) are an important part of any baseline work-up. Although they may be within normal limits, they may reveal stones or tumors associated with the urinary tract, or rule out other diseases and causes of the patients’ clinical signs.
Abdominal ultrasound is recommended in individuals with recurrent cystitis. It is very helpful in evaluating the urinary tract structures. There are characteristic changes seen within the renal pelvis (inside of the kidney) that are consistent with pyelonephritis, which may be chronically seeding the lower urinary tract. Ultrasound is also helpful in evaluating for the presence of stones or tumors throughout the urinary tract. It is a noninvasive procedure that often necessitates the expertise of a specialist and/or referral hospital.
Your veterinarian may recommend additional tests to exclude or diagnose concurrent conditions. These tests are not always necessary in every case, but they may be of benefit in certain individuals, and are selected on a case-by-case basis. These include;
Cystoscopy. This procedure allows your veterinarian to visualize and sample tissue from the lower urinary tract. It does necessitate general anesthesia, as well as the expertise of a specialist, and transfer to a facility that has the proper equipment. It may be very helpful in making a definitive diagnosis in certain cases.
Endocrine testing to include an ACTH stimulation test and a thyroid profile to rule out hyperadrenocorticism (Cushing’s disease) and hyperthyroidism, respectively. They are blood tests that can usually be performed at your local veterinary hospital.
A contrast cystourethrogram. This dye study evaluates the entire urinary bladder and urethra. It may confirm the presence of a tumor, stone or structural abnormality.
Excretory urography. This intravenous dye study “lights up” the upper urinary tract (kidneys and ureters). It is very helpful in documenting pyelonephritis, and is also of benefit in some cases as it helps detect stones in the urinary tract, and may identify other abnormalities, such as ectopic ureters. An ectopic ureter is a congenital abnormality in which the ureter (the tube that drains the kidney into the bladder) joins the bladder in an abnormal position, causing a host of clinical signs, most commonly, urinary incontinence (leaking) and recurrent infections.
In some cases, a bladder biopsy may be of benefit. This is an invasive procedure that often necessitates abdominal surgery.
In-depth Information on Therapy
Most dogs are stable, and can be treated as outpatients as long as they are monitored closely for response to therapy. With appropriate therapy, and/or the identification and treatment of an underlying disorder, most patients do well, and can expect to see a full recovery. Correction or treatment of any underlying predisposing factors such as stones, prostatitis/metritis or cancer is imperative to treatment.
In more chronic cases, response to therapy can take longer and occasionally, response may be poor. Chronic, recurring cystitis can cause the development of stones, or cause the extension of infection to other parts of the urinary tract and body. It is very important that all recommendations by your veterinarian are followed very closely, and any questions or concerns that arise during the treatment protocol are addressed immediately.
Antibiotic therapy selected on the basis of bacterial culture and sensitivity of the urine or bladder mucosa (tissue) is the most important part if therapy. It is important to administer all medication as directed by your veterinarian. Usually, a minimum of 4-6 week treatment protocol is indicated in these recurring cases. Occasionally, extended or repeat antibiotic courses are in order. In some cases, long term (months) before bedtime administration is recommended.
Dietary modification is recommended in animals with concurrent kidney failure or stones. Surgical intervention may be necessary in cases of stones or tumors.
Follow-Up Care for Dogs with Recurrent Bladder Infections
Optimal treatment for your dog requires a combination of home and professional veterinary care. Follow-up can be critical, especially if your pet does not rapidly improve.
Administer all prescribed medication as directed. Alert your veterinarian if you are experiencing problems treating your pet. The exact dose, frequency and length of proper antibiotic administration are imperative.
Repeat the urine culture approximately 7-10 days into treatment, and 1-2 weeks after the entire course of treatment has been completed. It is important to obtain urine cultures every 2-3 months until 3 negative cultures are obtained in these cases of chronic, recurrent cystitis. If at any point the culture is positive, an additional course of antibiotics, often longer than the original course, is generally recommended. Infection may persist in some animals despite appropriate, repeated courses of antibiotics.
General blood work (complete blood count, biochemical profile, etc.) may need to be reevaluated as recommended by your veterinarian.