| (1) |
In general pathogens colonize the urinary tract by ascension from the urethra. A resident apathogenic flora in the distal urethra occupies the epithelium and produces bacteriocins to prevent invasion of pathogens. |
| (2) |
Voiding is the most effective defense mechanism, eliminating around 95% of bacteria having succeded to ascend to the bladder. Peristalsis and a high pressure zone in the midth of the urethra also contribute to host defense. |
| (3) |
Antibacterial secretions of mucosa and prostate, as well as a protective glycosaminoglycan layer over the inner surface of the bladder prevent adhesion of urinary pathogens. |
| (4) |
Low pH and high urea concentrations make urine a hostile environment for pathogens. Production of ammonia by urease bacteria increases urine pH and makes the milieu more suitable for growth of pathogens. |
| (5) |
Intact male dogs frequently suffer from bacterial prostatitis with inflammatory reactions and forming of huge abscesses. |
| (6) |
Urolithiasis, frequently seen in neutered tomcats, but also in dogs, further complicates the pathologic condition. |
| (7) |
In immunecompromised animals ascending infection via the ureters to the kidneys is possible, whereas hematogeneous infection of the urinary tract is quite rare. |
| (8) |
Glomerular basement membrane and endothel of kidney tubules are very susceptible to damage. Here bacterial toxins quickly lead to impairement of proper kidney function and irreversible damage |
