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  • Author or Editor: Edward D. Roberts x
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SUMMARY

Topically applied 4% timolol, 4% timolol combined with 2% pilocarpine, 6% timolol, and 6% timolol combined with 2% pilocarpine were evaluated in clinically normal Beagles and Beagles with glaucoma. The drugs were instilled twice daily for 5 days. Changes in intraocular pressure (iop), pupil size, and heart rate were recorded on days 1, 3, and 5 at 0, 2, 5, and 8 hours, starting at 8:30 am. In clinically normal dogs, 4 and 6% topically administered timolol did not cause consistent reductions in iop; however, with addition of 2% pilocarpine, iop was consistently lower. In the Beagles with glaucoma, 4 and 6% timolol and, to a greater extent, 4 and 6% timolol combined with 2% pilocarpine lowered iop. The combinations lowered iop and reduced pupil size consistently. In all test groups, either 4 or 6% topically applied timolol caused approximately 10% decrease in mean heart rate.

Free access
in American Journal of Veterinary Research

Summary

Ciprofloxacin, a fluoroquinolone antimicrobial agent, was administered orally to 4 healthy dogs at dosage of approximately 11 and 23 mg/kg of body weight, every 12 hours for 4 days, with a 4-week interval between dosing regimens. Serum and tissue cage fluid (tcf) concentrations of ciprofloxacin were measured after the first and seventh dose of each dosing regimen. The peak concentration was greatest in the serum after multiple doses of 23 mg/kg (mean ± sem; 5.68 ± 0.54 μg/ml) and least in the tcf after a single dose of 11 mg/kg (0.43 ± 0.54 μg/ml). The time to peak concentration was not influenced by multiple dosing or drug dose, but was longer for tcf (6.41 ± 0.52 hour) than for serum (1.53 ± 0.52 hour). Accumulation of ciprofloxacin was reflected by the area under the concentration curve from 0 to 12 hours after administration (AUC0→12). The AUC0→12 was greatest in the serum after multiple doses of 23 mg/kg (31.95 ± 1.90 μg·h/ml) and least in the tcf after a single dose of 11 mg/kg (3.87 ± 1.90 μg·h/ml). The elimination half-life was not influenced by multiple dosing or dose concentration, but was greater for tcf (14.59 ± 1.91 hours) than for serum (5.14 ± 1.91 hours). The percentage of tcf penetration (AUCTCF/AUCserum ) was greater after multiple doses (95.76 ± 6.79%) than after a single dose (55.55 ± 6.79%) and was not different between doses of 11 and 23 mg/kg. Both dosing regimens of ciprofloxacin resulted in continuous serum and tcf concentrations > 90% of the minimal inhibitory concentration for the aerobic and facultative anaerobic clinical isolates tested, including Pseudomonas aeruginosa.

Free access
in American Journal of Veterinary Research

Summary

To evaluate the clinical, laboratory, and histologic effects of 2 methods of treatment for infectious arthritis in horses, Staphylococcus aureus (3.4 to 3.9 × 103 colony-forming units) was inoculated into the tarsocrural joints of 8 horses on day 0. Each horse was treated with phenylbutazone (2 g, po, q 24 h) and gentamicin sulfate (2.2 mg/kg of body weight, iv, q 8 h) for 14 days. On day 2, general anesthesia was induced, and each horse had 1 tarsocrural joint treated by arthrotomy, with removal of accessible fibrin and lavage with 3 L of sterile balanced electrolyte solution. An indwelling plastic drain was placed in the standing horse to provide a means for lavage with 3 L of balanced electrolyte solution twice daily for 72 hours. The contralateral tarsocrural joint was treated via arthroscopic debridement, synovectomy, and lavage with 3 L of balanced electrolyte solution. Arthrotomy and arthroscopic portals were allowed to heal by second intention. Lameness and thermographic examinations, analysis and bacteriologic culture of synovia, cbc, and wbc differential count were performed prior to inoculation and on days 1, 3, 6, 8, and 13. On day 14, each horse was euthanatized, and the joints were measured, opened, and photographed. Synovium and articular cartilage were obtained for semiquantitative histologic (H&E stain) and histochemical (safranin O fast green stain) evaluation. Lameness and joint circumference were significantly (P < 0.05) greater in limbs treated by arthroscopy, synovectomy, and lavage. Arthrotomy with lavage eliminated the S aureus infection significantly (P < 0.05) earlier than arthroscopy, synovectomy, and lavage; however, both treatments eliminated the infection in all but a single joint. Contamination with other organisms (Streptococcus spp and Enterobacter spp) developed significantly (P < 0.05) more often in joints treated by arthrotomy. These results suggested that arthrotomy with lavage was more effective in eliminating joint infection by providing better drainage than arthroscopy, synovectomy, and lavage; however, arthrotomy had a higher risk of ascending bacterial contamination of the joint.

Free access
in American Journal of Veterinary Research