Urinary & Respiratory Tract Pathogens

Question 1

What are the primary methods of antimicrobial defense for the urinary tract?

Answer 1

• Washout by urine
• bacterial interference via colonization of distal urethra
• Glycoprotein layer - mucin
• Epithelial desquamation
• Local & systemic immune systems: sIgA, MMP, cytokines during infection, rapid mobilization of cellular immune response

Question 2

What are the antimicrobial properties of urine?

Answer 2

• High osmolality (esp. cats)
  
  • Double edged sword b/c also suppresses leukocyte function
• Urine pH
• Urea, methionine, hippuric and ascorbic acid, ammonium nitrogen

Question 3

Describe the characteristics of UTIs

Answer 3

• Most common infectious dz in dogs
• Ascending route = most common
• hematogenous route rare but can occur
• cats relatively resistant to UTI except geriatrics w/ renal failure

Question 4

What are the clinical signs of UTIs?

Answer 4

• Dysuria, incr freq/volume, excessive thirst, pyrexia and/or hematuria, crystalluria/uroliths, lower back pain

Should R/O: bladder neoplasms, urinary obstructions, renal masses, urolithiasis (schnauzers, dachshund, Dalmatians, pugs, bulldogs, Welsh corgis, beagles, terriers)

Question 5

Describe the technique for urine sampling and cultures

Answer 5

• Best sample = abdominal cystocentesis, then catheter
• Centrifuge at 200g for 15 min, streak pellet on BAP and MAC agars
• Gram and Giemsa stain of pellet
• Count < 1000/ml not significant, clinical bacteruria > 100,000/ml

Question 6

What are the various methods of diagnosing and treating UTIs?

Answer 6

Question 7

What are the various types of bacteria that can cause UTIs?

Answer 7

Question 8

Describe the characteristics of mastitis

Answer 8

• Seen in postpartum dogs, rare in cats
• most likely pathogens = E. Coli, Staph spp.
• antibiotics pass to offspring —> don’t use tetracycline, chloramphenicol, aminoglycosides
• can use cephalexin or clavamox

Question 9

What are the bacterial agents that cause pyometra?

Answer 9

• Most likely sources of uterine contamination (e.g. normal vaginal flora, subclinical UTI)
• E. Coli = most common
• Also Staph, Strep, Pseudomonas, or Proteus

Question 10

Describe the characteristics of prostatitis

Answer 10

• Route of infection = hematogenous or ascending from urethra
• often concurrent UTI b/c prostatic fluid reflexes into bladder
• Potential agents = E. Coli, Staph, Strep, Mycoplasma/Ureaplasma

Question 11

How do you treat prostatitis?

Answer 11

• Fluid therapy if dehydration or shock
• Abx selection on basis of sensitivity testing given for 1-4 wks
• large prostatic abscesses - drain surgically
• after infection resolved, castration should be considered
• chronic bacterial prostatitis = difficult to resolve

Question 12

What are the primary canine urogenital pathogens?

Answer 12

Question 13

What are some feline urogenital pathogens?

Answer 13

• FIP: immune mediated pyogranulomas of the kidneys
• FeLV: immune mediated glomerulonephritis, fetal absorption, abortion, renal lymphoma
• Feline panleukemia virus: abortion, congenital abnormalities
• FHV-1: abortion