Dysuria and Urinary Tract Infections PDF

Dysuria and Urinary Tract Infections Please open Echo360 to participate in polls Jennifer M. Reinhart, DVM, PhD, DACVIM, DACVCP Assistant Professor, Small Animal Internal Medicine [email protected] Learning objectives Urinary “Issues” • Know the cardinal signs of lower urinary tract disease...

Dysuria and Urinary Tract Infections Please open Echo360 to participate in polls Jennifer M. Reinhart, DVM, PhD, DACVIM, DACVCP Assistant Professor, Small Animal Internal Medicine [email protected] Learning objectives Urinary “Issues” • Know the cardinal signs of lower urinary tract disease • Diseases of the urinary tract present in many different forms • Be able to identify predisposing factors for urinary tract infections • Be able to differentiate urinary tract infections from subclinical bacteriuria • Be able to generate a treatment plan for sporadic vs. recurrent urinary tract infections Upper Urinary Tract: • Kidneys • Our job is to localize the disease to appropriate part of the urinary tract • Most abnormal urination can be classified as: • Polyuria • Pollackiuria • Incontinence Lower Urinary Tract: • Ureters* • Urinary Bladder • Urethra • Prostate • Vestibule/Vulva • Penis/Prepuce Urinary Localization – Polyuria Urinary Localization – Pollakiuria • Def. – increased volume of urine • Usually normal frequency, but large amounts (big puddles) • Def. – increased frequency of urination • Accidents happen when bladder gets too full • Localizes disease to the upper urinary tract • Also caused by systemic disease affecting the kidneys • E.g., CKD, diabetes mellitus, Cushing’s disease, hepatic insufficiency • Increased urge • Small, frequent urinations • May urinate multiple times in one trip outside or to the litterbox • Localizes disease to the lower urinary tract • Indicates irritation within the bladder, urethra, prostate, etc. Urinary Localization – Incontinence Lower Urinary Tract Disease (LUTD) • Def. – Unconscious, passive voiding of urine • Volume and frequency variable, animal is unaware of voiding • Three cardinal signs of lower urinary tract disease • May occur while sitting or asleep • May have urine scald • Generally, localizes disease to bladder neck or below • Can also be a manifestation of neuromuscular disease • Animals with polyuria and pollakiuria know when they’re voiding, incontinent animals don’t • Pollakiuria – increased frequency of urination • Stranguria – straining to urinate • Hematuria – blood in the urine • Urine may also smell foul • The fourth cardinal sign – “stankuria” • All signs of LUTD may be classified as: • Dysuria – difficulty urinating LUTD – Differentials LUTD – Diagnostics • Lower urinary tract infection • Urinalysis • Urine Culture • Abdominal radiographs and/or ultrasound • Cystitis, prostatitis, urethritis, vulvovaginitis • Feline idiopathic cystitis • Urolithiasis • Neoplasia • Transitional cell carcinoma, prostatic adenocarcinoma • Iatrogenic – catheterization, surgery, drug induced (cyclophosphamide) • CBC/chemistry LUTD Knowledge Check #1 Urinary Tract Infections (UTIs) An 8 yo FS Golden Retriever presents to you for urinary accidents in the house. Write down a follow-up question you might ask the owner to better determine the cause of the accidents. • Def. – invasion, adherence, and persistence of a pathogenic organism in the urinary tract • > 99% of UTIs are caused by bacteria Pyelonephritis • <1% fungus (Candida), Capillaria spp., Mycoplasma/Ureoplasma spp., viruses • Defined by location • Different locations managed differently Cystitis Prostatitis Urinary Tract Infections (UTIs) – Types Bacterial Cystitis • Cystitis • Very common in dogs • Sporadic cystitis (i.e., simple or uncomplicated) • Usually, an isolated incident (< 3 per year) • Usually occurs in otherwise healthy dogs • Recurrent cystitis (i.e., complicated) • 3 or more per year • Implies a predisposing factor is present • Prostatitis • 14% lifetime risk • Uncommon in cats • < 10% of cats with lower urinary tract signs have infection • In both species • Female > male • Older animals more common • More on this in prostate lecture • Pyelonephritis Bacterial Cystitis Bacterial Cystitis • Host Defenses of the Lower Urinary Tract • Impairment Host Defenses Predisposes to UTI • Normal micturition • Anatomic structures • Urethral sphincters, length • Prostatic secretions • Urothelial defense barriers • Glycosaminoglycans • Exfoliation of urothelial cells • Mucosal immunity • Normal micturition • Anatomic structures • Urethral sphincters, length • Prostatic secretions • Urothelial defense barriers • Glycosaminoglycans • Exfoliation of urothelial cells • Mucosal immunity Failure to void normally e.g., paraparesis, detrusor muscle atony, indwelling urinary catheter Urethral sphincter mechanism incontinence (USMI), ectopic ureters, vaginovulvar conformational abnormalities Urolithiasis, neoplasia • Antimicrobial properties of urine • Antimicrobial properties of urine CKD, diabetes mellitus, Cushing’s disease • Systemic immunocompetence • Systemic immunocompetence Drugs, systemic illness • pH, hyperosmolality, defense peptides • pH, hyperosmolality, defense peptides Bacterial Cystitis – Organisms Bacterial Cystitis – Diagnosis • Dogs Clinical signs • Lower urinary tract signs • > 60% are Gram-negative organisms • 45-55% all positive cultures are E. coli • Others: Proteus, Pseudomonas, and Klebisella spp. • Pollackiuria, hematuria, stranguria • Gram-positive organisms • Clinical signs MUST be present to diagnose bacterial cystitis • Animals with only bacterial cystitis should NOT feel sick • Staphylococcus, Streptococcus, and Enterococcus spp. • Cats • ~50% are Gram-negative • 37% all positive cultures are E. coli • ~50% are Gram-positive • Fever, inappetence, vomiting, lethargy indicate • 27% all positive cultures are Enterococcus spp. • Upper urinary tract infection (pyelonephritis) • Prostatitis (intact males only) • OR non-urinary systemic disease • Polymicrobial infections can occur • ~23% in dogs Bacterial Cystitis – Diagnosis Bacterial Cystitis – Diagnosis Urinalysis • Can detect bacteriuria on sediment Quantitative Urine Culture • Positive culture + clinical signs is definitive for UTI • Perform on cystocentesis sample • Rods > cocci • Care with over interpretation • Stain precipitate can be mistaken for bacteria • Bacteriuria can be normal on voided samples bacteriuria • Pyuria (> 3-5 WBCs/hpc) is supportive • But not diagnostic – other reasons for pyuria • Evidence of underlying disease • E.g., glucosuria, ketonuria stain precipitate • Store in refrigerator • Submit within 24 h of collection • Isolates with < 1,000 CFUs are likely due to contamination, not infection • ALWAYS perform susceptibility on clinically relevant isolates Bacterial Cystitis – Diagnosis Bacterial Cystitis – Diagnosis Quantitative Urine Culture • Positive culture WITHOUT clinical signs is NOT bacterial cystitis Subclinical Bacteriuria OR (Asymptomatic Bacteriuria) • These cases generally do not require treatment Other Diagnostics • Abdominal radiographs/ultrasound • Treatment of asymptomatic bacteriuria leads to antibiotic overuse and ANTIMICROBIAL RESISTANCE • Other reasons to culture urine • Screen for uroliths and tumors as a nidus for infection • CBC/Chemistry • Screen for systemic predisposing factors • Cystitis alone should NOT cause inflammatory leukogram • Renal or prostatic involvement • Cystitis alone should NOT cause azotemia • Dilute urine from CKD may predispose to UTI • Pyelonephritis • Pyelonephritis, septicemia Bacterial Cystitis – Diagnostics by Type Sporadic Bacterial Cystitis – Treatment Sporadic Bacterial Cystitis Recurrent Bacterial Cystitis • MUST: Urinalysis • MUST: Urinalysis and Culture • RECOMMENDED: • Begin empiric therapy while awaiting culture results • Document presence of bacteriuria • PREFERRED: Quantitative urine culture • CONSIDER: additional diagnostics • If underlying disease is suspected • CBC, chem • Abdominal imaging • Many of these animals have at least one predisposing factor • Alleviates discomfort • Empiric antibiotic choices • Amoxicillin • Amoxi/clav not always necessary • Depends on regional resistance patterns • Trimethoprim-sulfonamide combination • Treatment time: 3-5 days Sporadic Bacterial Cystitis – Treatment Recurrent Bacterial Cystitis – Treatment • If infection is resistant to empiric antibiotic: • If animal is clinically responding à continue empiric antibiotic • Amoxicillin and TMS reach very high concentrations in urine, may overcome resistance • If not à switch abx based on C&S • Treat for full 3-5 days • DO NOT need to complete initial course of antibiotics • If animal is not responding within 48 h: • Further investigation • Is UTI actually present? • Are there complicating factors • Switch to C&S-based antibiotic Diagnosis Abx Therapy d/c Abx Later INTERPRETATION IDEAL REINFECTION Structural, functional, or immunologic abnormality predisposing to infection RELAPSE Nidus/reservoir for infection (e.g., stone, tumor) PERSISTENCE OR SUPERINFECTION Ineffective drug therapy (e.g., poor drug penetration, resistance) Direct route from outside body to bladder (e.g., urinary catheter) Recurrent Bacterial Cystitis – Treatment Bacterial Cystitis – Treatment • Address predisposing factor! • Antibiotic therapy based on C&S Multi-Drug Resistant Organisms • Before selecting drug – confirm that this is a UTI and not subclinical bacteriuria • Consider an extended susceptibility pattern • Resistance more common in complicated cases • Until C&S is available, consider • NSAID therapy (dogs only) • Empiric antibiotics as for sporadic cystitis • Treatment time: depends on situation • Reinfection: 3-5 days (as for sporadic cystitis) • Relapse or Persistence: 7-14 days • Chloramphenicol • Macrolides • Nitrofurantoin • Consider high-dose amoxicillin/clavulanate, especially for E. coli • 25 mg/kg q 8 h • Ask for help from a specialist • Internist or bacteriologist Bacterial Cystitis – Follow Up Bacterial Cystitis – Prevention • Sporadic Bacterial Cystitis • Correct/manage predisposing conditions • None needed if clinical signs resolve • Recurrent Bacterial Cystitis • Repeat culture 1-2 weeks after treatment discontinuation • Interpret results in light of clinical signs • Episioplasty/weight loss for hooded vulva • Modify immunosuppressive regimen • Dissolve/remove uroliths • Compounds to prevent bacterial adherence • • • • Proanthocyanidins (cranberry extract) D-mannose Glycosaminoglycan supplements (Adequan) No strong studies to support use at this time LUTD Knowledge Check #2 Pyelonephritis A 2 yo FS Bulldog presents to you for pollackiuria and hematuria. She has had three UTI episodes the past year, two caused by E. coli and one caused by Klebsiella spp. Her urinalysis shows bacteriuria and pyuria, and you submit an aerobic urine culture. What is an appropriate empiric therapy? A) Enrofloxacin for 3 days B) Amoxicillin for 5 days C) Enrofloxacin for 10 days D) Amoxicillin for 14 days • Def. – inflammation of the renal pelvis extending into the parenchyma • Usually, bacterial infections ascending from the lower urinary tract • Involvement of the renal parenchyma à acute kidney injury • Pyelonephritis is both a UTI and a cause of AKI • Principles of both apply Pyelonephritis – Presentation Pyelonephritis – Presentation Predisposing Factors • Any factor predisposing to lower UTI • Ureteral abnormalities Clinical Signs • Asymptomatic to life threatening • Can be vague – lethargy, anorexia, vomiting • Can localize to renal parenchyma – polyuria/polydipsia, renal pain • Can be evidence of systemic inflammation – fever • Can include LUT signs – pollackiuria, hematuria, stranguria • Congenital abnormalities, strictures, ureteroliths • Systemic immunosuppression Pyelonephritis – Diagnostics Pyelonephritis – Diagnostics • CBC • Quantitative urine culture • +/- inflammatory leukogram • Chemistry • +/- azotemia • Evidence of comorbidities, predisposing factors • Urinalysis • Dilute urine, cylindruria – evidence of renal tubular damage • Bacteriuria, pyuria, proteinuria – may be harder to detect than with LUTI • Glucosuria/ketonuria – evidence of comorbidity/predisposing factor • Definitive diagnosis requires pyelocentesis • Cystocentesis sample is usually adequate • False negatives possible • Abdominal ultrasound • Pyelectasia is most definitive finding • Other causes for pyelectasia • • • • Fluid therapy (mild) Polyuric disease (mild) Ureteral obstruction (mild to severe) Chronic kidney changes (mild) • Decreased corticomedullary definition – non-specific • Perinephric inflammation/fluid Pyelonephritis – Treatment Pyelonephritis – Prognosis • Begin empiric abx after culture collected • Generally good, if caught early and treated appropriately • Chronic, recurrent pyelonephritis can occur • Fluoroquinolone • Third generation cephalosporin • Adjust abx based on C&S results • Treat a total of 10-14 days • If signs of systemic illness (e.g., fever, anorexia), • Especially in patients with systemic disease (e.g., diabetes, CKD) • As with all AKI, some permanent renal injury can occur • Predisposes/progresses to CKD • At least 48-72 hours intravenous abx • Hospitalize for fluid and supportive therapy • If azotemia is present or non-azotemic but progressive rise in creatinine, • Treat as for AKI LUTD Knowledge Check #3 References A 5 yo MC DSH presents to you for a 7-month history of diarrhea with normal appetite, attitude, urination and drinking. Complete blood count and biochemistry panel are normal. Urinalysis shows concentrated urine (USG 1.045), 0-1 WBC/hpf, and 3+ cocci. What is the most likely cause of the bacteriuria? A) Sporadic cystitis B) Recurrent cystitis C) Pyelonephritis D) Asymptomatic bacteriuria • Wood MW. Chapter 330: Lower Urinary Tract Infections. Textbook of Veterinary Internal Medicine. Ettinger SJ, Feldman EC, Cote E, editors. 8th ed. 2017. • Van Dongen. Chapter 327: Pyelonephritis. Textbook of Veterinary Internal Medicine. Ettinger SJ, Feldman EC, Cote E, editors. 8th ed. 2017. • Weese JS, et al. 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. 2019;247:825. QUEST ONS?