Cystitis: bacterial

• Inflammation of the bladder due to bacterial lower urinary tract infection.
• Cause: usually an ascending bacterial infection; predisposing factors are generally necessary for this opportunistic infection, ie rarely the initial cause in cats.
• Signs: stranguria, dysuria, increased frequency of urination (pollakiuria) and small amounts of urine, hematuria.
• Diagnosis: urine cytology and culture.
• Treatment: antibiotics, supportive care (ie pain relief when appropriate).
• Prognosis: generally good.
  Print off the owner factsheet Cystitis (bladder inflammation) Cystitis (bladder inflammation)  to give to your client.

• Dysuria.
• Stranguria.
• Pollakiuria.

• Hematuria.

• Asymptomatic (in 0.6 to 29% of cats with positive urine culture).

• Bacterial infection (often E. coli  Escherichia coli, Staphylococcus  Staphylococcus spp  , Enterococcus, Streptococcus  Streptococcus spp, Klebsiella Klebsiella  pneumoniae, Proteus Proteus spp).

General

Causes of lower urinary tract infection and/or inflammation

• Trauma.
• Iatrogenic - catheterization.
• Glucocorticoids (iatrogenic, hyperadrenocorticism).
• Glucosuria (diabetes mellitus, Fanconi's syndrome).

• Decreased urine concentration (polyuria).
• Indwelling urinary catheters.
• Urolithiasis Urolithiasis.
• Urethrostomy Urethrostomy.
• Feline idiopathic cystitis Idiopathic cystitis.

• Bladder distension (neurological or polyuria) increases binding sites for bacteria and reduces blood flow in bladder wall.
• Decreased urethral function.
• Neoplasia Bladder: neoplasia.

Specific

• Anatomical abnormality Bladder: developmental anomaly: diverticulum Bladder: diverticulum, persistent urachus Persistent urachus, ectopic ureter  Ureter: ectopic, caudal bladder neck.

• It is usually an ascending bacterial infection, less likely a hematogenous infection, and generally requires a predisposing factor in cats (different from dogs).
• Predisposing factors + opportunistic microbes  →  ascending into bladder  →  cystitis  →  pyelonephritis Pyelonephritis.

• Stranguria/dysuria.
• Hematuria Hematuria.
• Pain (caudal abdominal or lumbar).

• Stranguria.
• Pollakiuria.

• Hematuria.

• Asymptomatic.

• Small, empty bladder on abdominal palpation is most common.
• Thickened bladder wall on abdominal palpation.

Urinalysis

• Cystocentesis Cystocentesis.
• Hematuria Hematuria  Urinalysis: blood.
• Active sediment examination Urinalysis: centrifuged sediment with more than 5 WBC/high power field. In cases of excess glucocorticosteroids the sediment examination is often non-inflammatory and culture is necessary. Bacteria Urinalysis: culture and sensitivity on sediment examination may originate from kidney, ureter, bladder or prostate or be a contaminant.
• Positive urine culture Urinalysis: culture and sensitivity with more than 10* 5 bacteria/mL.
• Sensitivity testing based on urine concentrations of antibiotics, rather than serum concentrations.

Radiography

• Considered to assess size and position of bladder and kidneys.
• Important to check for calculi   and exposure factors before giving contrast radiography.

Contrast radiography

• Double contrast urography Radiography: double contrast cystography shows thickened and irregular bladder wall in chronic cases   .
• Small bladder in most cases, unless animal is polyuric or has a distal urinary tract obstruction or neurologic urine retention.
• Bladder wall irregularities on double contrast study.
• Urolithiasis Urolithiasis.
• Bladder diverticulum Bladder: diverticulum on positive or double contrast study.
• Bladder neoplasia Bladder: neoplasia, most common in the bladder trigone area, visible on double or positive contrast study.
• Emphysematous cystitis.

Ultrasonography

• Thickened bladder wall   .
• Echogenic sediment in bladder.
• Diverticulum (can only be accurately evaluated with a full bladder).
• Urolithiasis causing acoustic shadowing.
• Irregular bladder wall due to polyps, neoplasia   .
• Intraluminal gas in case of emphysematous cystitis. 

Biochemistry

• Frequently unremarkable. 
• Renal azotemia Blood biochemistry: urea, indicating involvement of kidneys. Cystitis alone does not cause azotemia Azotemia.

Hematology

• Leucocytosis (uncommon) Hematology: leucocyte (WBC), indicating severe infection, inflammation or even sepsis. Uncomplicated cystitis does not cause leukocytosis.

Histopathology

• Bladder wall biopsy shows evidence of neutrophilic inflammation and the possibility to assess severity of the disease.
• Culture biopsy to find infectious cause.
• May be necessary to rule out neoplasia but rarely indicated.

• Thickened bladder wall.

• Evidence of underlying cause   .

• Inflammatory cell infiltrate in bladder wall.

• Follicular proliferation of lymphoid tissue in bladder wall in chronic cases.

• Formation of chronic inflammatory polyps.
• Bladder wall fibrosis.

Feline idiopathic cystitis

• Often mistaken for bacterial cystitis Feline lower urinary tract disease (FLUTD).

Secondary cystitis

• Bladder diverticulum Bladder: diverticulum, ectopic ureters Ureter: ectopic or persistent urachus Persistent urachus.
• Urolithiasis Urolithiasis.
• Neoplasia Bladder: neoplasia.
• Lower urinary tract obstruction Urethra: obstruction.
• Diabetes mellitus Diabetes mellitus.
• Immunosuppressive treatment/Hyperadrenocorticism Hyperadrenocorticism.

Hematuria

• Urolithiasis. 
• FIC Idiopathic cystitis. 
• Trauma Bladder: trauma rupture.
• Neoplasia Bladder: neoplasia.
• Clotting disorders.
• Renal hemorrhage.

Tenesmus

• Other causes of Feline lower urinary tract disease Feline lower urinary tract disease (FLUTD). 
• Colon disease Colitis.
• (Peri-)anal or rectal disease.
• Constipation Constipation or obstipation.

• Antibiosis for 3-5 days for uncomplicated urinary tract infection Therapeutics: urinary system.
• 7-14 days for persistent or relapsing urinary tract infections. 
• 10 to 14 days for pyelonephritis. 
• Follow treatment with second urine culture in chronic or recurrent cases.
• May need analgesics if some patients. 

• Treat underlying cause.
• Antibiosis based on urine culture and sensitivity ideally.
  Best given late at night (urine storage overnight).

• Encourage frequent voiding of urine.

• Induction of polyuria (increase water intake).
• Urinary antiseptics (methenamine mandelate, methenamine hippurate Methenamine hippurate) not recommended for uncomplicated urinary tract infections and evidence is lacking for management of recurrent non-responsive cases.

Monitoring

• Resolution of clinical signs.
• In persistent urinary tract infection, the urine should be cultured before the discontinuation of the antibiotic treatment. If the culture is still positive, antibiotics should be changed on the basis of sensitivity.
• In recurrent urinary tract infection, the urine should be recultured 7 days after finishing antibiotic therapy and then on a monthly basis (3 times) to monitor recurrence.
• Prophylactic antibiotherapy is not recommended. 
• Recurrence should stimulate another careful search for underlying cause.

• Good: If uncomplicated primary cystitis and underlying cause identified and removed.
• Guarded: If cannot remove underlying cause, or if complications.
• Poor: If underlying malignant neoplasia.

• Resolution of clinical signs usually within days of starting appropriate treatment.

• Inappropriate antibiotic (not based on urine culture/sensitivity).
• Underlying cause not identified.
• Complications have occurred, eg pyelonephritis.
• Candidal urinary tract infection in immunocompromized animal or after long-term antibiotic therapy.
• Imbedded bacterial infections 'hidden' in kidney/bladder wall.

Refereed papers

• Recent references from PubMed and VetMedResource.
• Dorsch R, Teichmann-Knorrn S, Sjetne Lund H (2019) Urinary tract infection and subclinical bacteriuria in cats: A clinical update. J Feline Med Surg 21(11), 1023-1038 PubMed. 
• Weese J S, Blondeau J, Boothe D et al (2019) International Society for Companion Animal Infectious Diseases (ISCAID) guidelines for the diagnosis and management of bacterial urinary tract infections in dogs and cats. Vet J 247, 8-25 PubMed. 
• Teichmann-Knorrn S, Reese S, Wolf G et al (2018) Prevalence of feline urinary tract pathogens and antimicrobial resistance over five years. Vet Rec 183(1), 21 PubMed. 
• Lees G E (1996) Bacterial urinary tract infections. Vet Clin North Am Small Anim Pract 26 (2), 297-304 PubMed.
• Low D A, Braaten B A, Ling G V et al (1988) Isolation and comparison of Escherichia coli strains from canine and human patients with urinary tract infections. Infect Immunol 56 (10), 2601-2609 PubMed.