Page 977 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

952 CHAPTER 7

VetBooks.ir 7.33 7.34

Fig. 7.33 Removal of the urethrolith with a
haemostat. (Photo courtesy VK Kos)

Fig. 7.34 Perineal urethrostomy site in a stallion
with urethral obstruction and subsequent bladder
rupture.

Antimicrobials (procaine penicillin 20,000 IU/kg may occur in foals that undergo intensive antimicro-
i/m q12 h or trimethoprim/sulphadiazine 24–30 mg/ bial therapy. Habronema megastoma may also invade
kg p/o q12 h) are necessary in most cases of uroli- the urethral process, causing granulomas (Fig. 7.35).
thiasis, especially where the therapeutic procedures
are invasive. If concurrent infection is present, anti- Clinical presentation
biotic treatment should be based on urine culture Haematuria, haemospermia and stranguria are com-
and sensitivity results. mon presenting complaints. Resentment of manual
manipulation of the penis and sheath may be observed.
Prognosis
The prognosis depends on the severity of the ure- Differential diagnosis
thral lesion and secondary complications. Excessive Differential diagnoses include urethrolithiasis, ure-
tissue trauma increases the risk of urethral stricture. thral trauma, bladder paralysis, cantharidin toxico-
sis, neoplasia and vaginitis.
URETHRITIS
Diagnosis
Definition/overview Diagnosis is based on demonstration of the
Urethritis is an inflammatory condition of the ure- lesions by palpation and endoscopic examination.
thra that can be infectious or traumatic in origin. Ultrasonography may be helpful in excluding involve-
It usually develops secondary to cystitis, urethral ment of the accessory sex glands. Fractionation and
trauma (also post catheterisation), calculi or acces- examination of the ejaculate may provide similar
sory gland infection. Idiopathic urethritis is a pos- information. Bacterial culture of a urethral swab,
sible but uncommon disease in horses. urine and semen should be performed. Haematology
and urinalysis are not specific in primary urethritis.
Aetiology/pathophysiology
The urethra may provide a favourable environment Management
for colonisation by pathogens if its powerful defence Treatment involves sheath cleaning and topical
mechanisms are defeated. Gram-negative organisms treatment with anti-inflammatory and antibacterial
predominantly cause urethritis. Candida infection agents. Any primary disease causing the urethritis