Lecture 12

Question 1

What is the definition of a UTI?

Answer 1

presence of bacteria in urine of a patient with related clinical signs

Question 2

What are the clinical signs that could be related to UTI?

Answer 2

-dysuria
-pollakiuria (inc. frequency, small amounts)
-stranguria
-urgency of urination
-inappropriate urination
-urinary incontinence

Question 3

What is subclinical bacteriuria?

Answer 3

-presence of bacteria in urine with no related clinical signs
-no longer considered a pathologic state requiring therapy

Question 4

What is the etiopathogenesis of UTI?

Answer 4

-bacterial number and virulence are sufficient to overcome host defenses
-disease state alters host defense mechanisms

Question 5

What are the urinary tract defenses against bacterial colonization?

Answer 5

-tight sphincter
-frequent forceful voiding
-long urethra
-glycosaminoglycan coating
-regular shedding of epithelial cells
-urinary secretion of immunoglobulins and cytokines

Question 6

What are the characteristics of urine that help to prevent bacterial colonization?

Answer 6

-inhospitable pH
-high urine osmolality
-urinary inhibitors of bacterial adherence

Question 7

What leads to the clinical signs associated with UTI?

Answer 7

inflammatory response to bacterial colonization of urinary tract

Question 8

Which bacteria serve as a reservoir for UTI?

Answer 8

rectal and genital bacteria

Question 9

Which bacterial species account for the majority of UTIs?

Answer 9

-E. coli
-Staph. spp.
-Proteus mirabilis
-Enterococcus/Strep. spp.
-Klebsiella pneumoniae
-Pseudomonas aeruginosa
-Enterobacter cloacae

Question 10

What is the presentation of upper UTI?

Answer 10

-fever
-lethargy
-oliguria/anuria
-PUPD
-pain on palpation of kidneys

Question 11

What is the presentation of lower UTI?

Answer 11

any combo of:
-dysuria
-pollakiuria
-stranguria
-urgency
-hematuria
-inappropriate urination
-urge incontinence

Question 12

How does pollakiuria differ from polyuria?

Answer 12

-pollakiuria is increased frequency of small amounts of urination
-polyuria is increase in amount of urine production

Question 13

What are the physical exam findings in UTI patients?

Answer 13

-often unremarkable
-mucopurulent/bloody discharge at distal end of penis/vulva
-pain on rectal palpation if prostate involved (males)
-back pain with pyeloneprhitis

Question 14

What are the differential diagnoses for UTI?

Answer 14

-trauma
-neoplasia
-urolithiasis
-idiopathic detrusor instability

Question 15

What are the characteristics of sporadic bacterial cystitis?

Answer 15

-patients with first-time UTIs
-no predisposing condition identified
-otherwise healthy non-pregnant females or neutered males
-< 3 separate episodes of bacterial cystitis in preceding 12 months

Question 16

What are the characteristics of recurrent bacterial cystitis?

Answer 16

-patients with predisposing conditions
-history of recurrent UTIs
-intact male dogs

Question 17

What are possible predisposing conditions for cystitis/UTI?

Answer 17

-renal disease
-hyperadrenocorticism
-diabetes mellitus
-hyperthyroidism
-vulvar malformation
-uroliths
-tumors
-PKD
-immunosuppressive medications

Question 18

What counts as recurrent UTI?

Answer 18

-3 or more episodes in 12 months
-2 or more episodes in 6 months

Question 19

What are the characteristics of relapsing UTI?

Answer 19

-recurrence of same organism within weeks to months of successful therapy
-sterile bladder during therapy
-often a nidus; prostatitis, stones, neoplasia

Question 20

What are the characteristics of persistent UTI?

Answer 20

-persistent positive culture despite appropriate therapy
-no clearance during or after therapy
-rare
-occurs with compliance issues, drug issues, or structural abnormalities

Question 21

What are the characteristics of reinfection?

Answer 21

-recurrence with a different organism
-variable time
-occurs with immune dysfunction, loss of host defenses, structural abnormalities, or physiologic conditions

Question 22

What are the characteristics of superinfection?

Answer 22

-infection with different pathogen during therapy for another organism
-can occur with cystotomy tubes, indwelling catheters, or neoplasia

Question 23

What is included in a diagnostic work up for sporadic bacterial cystitis?

Answer 23

-thorough physical examination
-urinalysis that includes sediment exam
-urine culture

Question 24

What is included in a diagnostic work up for recurrent bacterial cystitis?

Answer 24

-thorough physical examination
-CBC
-chem panel
-urinalysis that includes sediment exam
-urine culture
-diagnostic imaging

Question 25

Which imaging modalities are used in recurrent bacterial cystitis cases?

Answer 25

*abdominal radiographs *abdominal ultrasound; better for: -uroliths -structural abnormalities -pyelectasia

Question 26

What is pyelonephritis?

Answer 26

infection of renal parenchyma from ascending lower UTI or bacteremia

Question 27

What are the clinicopathologic findings in pyelonephritis?

Answer 27

-azotemia -inflammatory leukogram -active urine sediment

Question 28

How is a diagnosis of pyelonephritis made?

Answer 28

*systemic clinical signs: -fever -lethargy -PUPD -renal pain *lab. findings *positive urine culture *imaging findings (renal pelvic dilation)

Question 29

What are the characteristics of urine culture?

Answer 29

-cornerstone of diagnosing/treating UTI -susceptibility testing essential to preventing widespread antibiotic resistance -more than 50% of submitted urine samples fail to grow bacteria -want to collect urine aseptically via cystocentesis

Question 30

What are the characteristics of cystocentesis?

Answer 30

-can be difficult in patients with UTIs, pollakiuria, and/or small bladders -abdominal ultrasound helpful in locating bladder during collection -catheterization possible alternative for "sterile" collection -voided sample NOT acceptable as alternative for "sterile" collection

Question 31

How should urine be stored for culture?

Answer 31

refrigerated immediately after collection and packaged cold for shipment to diagnostic lab

Question 32

How is an MIC test performed on urine?

Answer 32

-incubation of isolated bacteria with different dilutions of antibiotics -minimum concentration of antibiotic that inhibits growth is the bacteriostatic dose -want to choose an antibiotic in which the achievable concentration can be 4+ times greater than the MIC

Question 33

What are the characteristics of urine culture for pyelonephritis?

Answer 33

-urine collected via cystocentesis may not reflect bacteria in upper urinary tract -pyelocentesis collection possible but technically challenging -blood culture potentially a helpful alternative; esp. in immunosuppressed and febrile animals

Question 34

What are the treatment steps for sporadic bacterial cystitis?

Answer 34

-amoxicillin (+/- clavulanate) or TMS used for empirical therapy -treatment for 3 to 5 days -re-evaluation of antibiotics once culture and susceptibility results are available -reassess patient and differentials if no improvement after 48 hours -NSAIDs to decrease inflammation -post-therapy UA and culture not needed if signs resolve

Question 35

What must be considered in the treatment of recurrent bacterial cystitis?

Answer 35

-adequately control underlying endocrine disorders -consider surgical correction for recessed vulvas -reduce any immunosuppressive medications to lowest effective dose -do not repeat courses of antibiotics without correcting underlying problem(s); can create resistance

Question 36

What are the current treatment recommendations for recurrent bacterial cystitis?

Answer 36

-analgesics and empirical therapy while awaiting C&S results -short, 3 to 5 day treatments for reinfections -long, 7 to 14 day courses in persistent and relapsing infections

Question 37

What are the characteristics of intra-therapy culture for recurrent bacterial cystitis?

Answer 37

-culture during therapy not needed for short-course antibiotic treatment -culture at 5 to 7 days during long-course treatment can help determine need for continued treatment/changes in treatment

Question 38

What must be considered when treating UTIs in intact male dogs?

Answer 38

-UTIs can involve the prostate -only certain antibiotics can penetrate prostate -urinary tract can be re-invaded by sequestered bacteria if infection in prostate is not treated -must choose antibiotics based on C&S as well as ability to penetrate prostate

Question 39

Which antibiotics are possible choices for UTIs in male intact dogs?

Answer 39

-macrolides -lincosamides -TMS -chloramphenicol -fluoroquinolones

Question 40

What are the treatment steps for pyelonephritis?

Answer 40

-start with empirical therapy while awaiting C&S -initially select antibiotics that target Enterobacteriaeceae -often start with fluoroquinolone or cefpodoxime -susceptibility based on serum antimicrobial breakpoints instead of urine; change antibiotics as indicated -treat for 10 to 14 days -follow up should include exam, serum creatinine, UA, and culture