| Autor: |
Brooks, D. E., Andrew, S. E., Biros, D. J., Denis, H. M., Cutler, T. J., Strubbe, D. T., Gelatt, K. N. |
| Předmět: |
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| Zdroj: |
Veterinary Ophthalmology; Jun2000, Vol. 3 Issue 2/3, p121-125, 5p, 11 Color Photographs, 2 Charts |
| Abstrakt: |
Abstract Purpose To describe 11 clinical cases of ulcerative keratitis in horses associated with betahemolytic Streptococcus equi in Florida, USA. Methods Retrospective clinical study (1996–99). Results Beta-hemolytic Streptococcus equi was cultured from 11 horses with deep ulcers, descemetoceles or iris prolapse (n = 8), a suture abscess found with a penetrating keratoplasty for a stromal abscess (n = 1), and ulceration that developed following keratectomy/irradiation for corneal squamous cell carcinoma (n = 2). Beta-hemolytic Streptococcus equi subspecies zooepidemicus was found in 10 eyes and subspecies equi in one. Marked signs of uveitis including miosis and hypopyon were present in 8/11 (72.7%) eyes. Keratomalacia was severe in all eyes. The mean diameter of the ulcers associated with betahemolytic Streptococcus was 10.2 ± 6.1 mm. Eight of the eyes required conjunctival flap surgery (four grafts dehisced) and one eye corneal transplantation. Two eyes were treated with medication only. Isolate sensitivity to antibiotics included ampicillin (6/11), bacitracin (11/11), cephalothin (11/11), chloramphenicol (11/11), gentamicin (5/11), polymyxin B (2/11), and tobramycin (1/11). All isolates were resistant to neomycin. The average healing time was 44.7 ± 26.7 days. The visual outcome was positive in 8/11 eyes, and the globe retained in 9/11 eyes. Conclusions Although Gram-positive bacteria predominate in the normal conjunctival microflora of horses throughout the world, Gram-negative bacteria and fungi are more often isolated from equine ulcers. Beta-hemolytic Streptococcus spp. are associated with a very aggressive ulcerative keratitis with the capability to digest conjunctival graft tissue. Clinical signs are pronounced. Aggressive surgical and intensive medical therapy with topical antibiotics and protease inhibitors is indicated. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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