Pharmacokinetics of difloxacin and its concentration in body fluids and endometrial tissues of mares after repeated intragastric administration.

Pharmacokinetics of difloxacin and its distribution within the body fluids and endometrium of 6 mares were studied after intragastric (IG) administration of 5 individual doses. Difloxacin concentrations were serially measured in serum, urine, peritoneal fluid, synovial fluid, cerebrospinal fluid, and endometrium over 120 h. Bacterial susceptibility to difloxacin was determined for 174 equine pathogens over a 7-month period. Maximum serum concentration (Cmax) was 2.25 +/- 0.70 microg/mL at 3.12 +/- 2.63 h and Cmax after the 5th dose was 2.41 +/- 0.86 microg/mL at 97.86 +/- 1.45 h. The mean elimination half-life (t(1/2)) was 8.75 +/- 2.77 h and area under the serum concentration versus time curve (AUC) was 25.13 +/- 8.79 microg h/mL. Highest mean synovial fluid concentration was 1.26 +/- 0.49 microg/mL at 100 h. Highest mean peritoneal fluid concentration was 1.50 +/- 0.56 microg/mL at 98 h. Highest mean endometrial concentration was 0.78 +/- 0.48 microg/g at 97.5 h. Mean cerebrospinal fluid concentration was 0.87 +/- 0.52 microg/mL at 99 h. Highest mean urine concentration was 92.05 +/- 30.35 microg/mL at 104 h. All isolates of Salmonella spp. and Pasteurella spp. were susceptible. In general, gram-negative organisms were more susceptible than gram-positives. Difloxacin appears to be safe, adequately absorbed, and well distributed to body fluids and endometrial tissues of mares and may be useful in the treatment of susceptible bacterial infections in adult horses.

Jejunoileal anastomosis following small intestinal resection in horses: seven cases (1999-2001).

OBJECTIVE: To report the postoperative outcome in horses undergoing jejunoileal anastomosis performed with a 2-layer simple continuous technique. DESIGN: Retrospective study. ANIMALS: 7 horses. PROCEDURE: Information regarding signalment, clinical signs, findings at surgery, and postoperative complications was obtained from medical records of horses that underwent exploratory ventral midline celiotomy, small intestinal resection, and jejunoileal anastomosis to correct various small intestinal strangulating lesions. Follow-up information was obtained via telephone conversations with owners or trainers. RESULTS: Six males and 1 female of various breeds aged 10 months to 27 years and weighing 312 to 785 kg (686.4 to 1,727 lb) were included. The most common complications were mild to moderate tachycardia and mild to moderate signs of abdominal pain. Two horses developed incisional infections and soft, fluctuant swelling at the incision site following resolution of the infection. Follow-up time ranged from 7 to 17 months after surgery. Owners reported no further colic episodes and no diet change necessary following surgery. All horses had returned to their intended level of use. CONCLUSIONS AND CLINICAL RELEVANCE: Advantages to the jejunoileal technique include maintaining the normal ileocecal valve and a postoperative recovery period similar to that described following other small intestinal anastomoses. Jejunoileal anastomosis is a viable alternative to ileal bypass. This technique appears to result in a postoperative complication rate similar to that reported following jejunojejunostomy procedures.

Risk factors associated with fecal Salmonella shedding among hospitalized horses with signs of gastrointestinal tract disease.

OBJECTIVE: To estimate prevalence of and identify risk factors for fecal Salmonella shedding among hospitalized horses with signs of gastrointestinal tract disease. DESIGN: Cross-sectional study. ANIMALS: 465 hospitalized horses with gastrointestinal tract disease. PROCEDURE: Horses were classified as positive or negative for fecal Salmonella shedding during hospitalization by means of standard aerobic bacteriologic methods. The relationship between investigated exposure factors and fecal Salmonella shedding was examined by means of logistic regression. RESULTS: The overall prevalence of fecal Salmonella shedding was 13%. Salmonella serotype Newport was the most commonly isolated serotype (12/60 [20%]), followed by Anatum (8/60 [13%]), Java (13%), and Saint-paul (13%). Foals with gastrointestinal tract disease were 3.27 times as likely to be shedding Salmonella organisms as were adult horses with gastrointestinal tract disease. Adult horses that had been treated with antimicrobial drugs prior to hospitalization were 3.09 times as likely to be shedding Salmonella organisms as were adult horses that had not been treated with antimicrobial drugs prior to hospitalization. Adult horses that underwent abdominal surgery were 2.09 times as likely to be shedding Salmonella organisms as were adult horses that did not undergo abdominal surgery. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that a history of exposure to antimicrobial drugs prior to hospitalization and abdominal surgery during hospitalization were associated with Salmonella shedding in adult horses with gastrointestinal tract disease. Foals with gastrointestinal tract disease were more likely to shed Salmonella organisms than were adult horses with gastrointestinal tract disease.