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Risk factors for development of pleuropneumonia were determined by reviewing medical records of 45 horses with pleuropneumonia and 180 control horses examined between Jan 1, 1980 and Jan 1, 1990. Factors considered included age, breed, sex, occupation, transport farther than 500 miles within the previous week, racing within the previous 48 hours, viral respiratory tract infection or exposure to horses with viral respiratory tract disease within the previous 2 weeks, and vaccination against influenza or rhinopneumonitis within the previous 6 months. Results indicated that Thoroughbreds were at a greater risk of developing pleuropneumonia than were other horses, and Standardbreds were at a reduced risk. Transport farther than 500 miles and viral respiratory tract disease or exposure to horses with respiratory tract disease were determined to be risk factors for the development of pleuropneumonia.

Free access
in Journal of the American Veterinary Medical Association


OBJECTIVE To determine pharmacokinetics and pulmonary disposition of minocycline in horses after IV and intragastric administration.

ANIMALS 7 healthy adult horses.

PROCEDURES For experiment 1 of the study, minocycline was administered IV (2.2 mg/kg) or intragastrically (4 mg/kg) to 6 horses by use of a randomized crossover design. Plasma samples were obtained before and 16 times within 36 hours after minocycline administration. Bronchoalveolar lavage (BAL) was performed 4 times within 24 hours after minocycline administration for collection of pulmonary epithelial lining fluid (PELF) and BAL cells. For experiment 2, minocycline was administered intragastrically (4 mg/kg, q 12 h, for 5 doses) to 6 horses. Plasma samples were obtained before and 20 times within 96 hours after minocycline administration. A BAL was performed 6 times within 72 hours after minocycline administration for collection of PELF samples and BAL cells.

RESULTS Mean bioavailability of minocycline was 48% (range, 35% to 75%). At steady state, mean ± SD maximum concentration (Cmax) of minocycline in plasma was 2.3 ± 1.3 μg/mL, and terminal half-life was 11.8 ± 0.5 hours. Median time to Cmax (Tmax) was 1.3 hours (interquartile range [IQR], 1.0 to 1.5 hours). The Cmax and Tmax of minocycline in the PELF were 10.5 ± 12.8 μg/mL and 9.0 hours (IQR, 5.5 to 12.0 hours), respectively. The Cmax and Tmax for BAL cells were 0.24 ± 0.1 μg/mL and 6.0 hours (IQR, 0 to 6.0 hours), respectively.

CONCLUSIONS AND CLINICAL RELEVANCE Minocycline was distributed into the PELF and BAL cells of adult horses.

Full access
in American Journal of Veterinary Research


Sixteen helminth-free pony foals were inoculated with a mean (±sd) 2,000 (±545.5) infective Parascaris equorum eggs (day 0). Foals were allocated to replicates of 4, and treatments within each replicate were assigned at random. Treatment administered on postinoculation day (pid) 28 included no treatment (control), 0.2 mg of ivermectin/kg of body weight, 10 mg of oxibendazole/kg, or 6.6 mg of pyrantel base (pamoate)/kg. Paste formulations of the anthelmintics were administered orally. The foals were euthanatized 14 days after treatment (pid 42) and examined for P equorum larvae in the small intestine. The mean ± sd (and range) numbers of fourth-stage P equorum larvae recovered from nontreated foals and those treated with ivermectin, pyrantel, or oxibendazole were 1,603.8 ± 1,026.8 (305 to 2,480), 29.3 ± 55.8 (0 to 113), 413.0 ± 568.1 (0 to 1,204), or 889.5 ± 1,123.1 (1 to 2,345), respectively. Compared with the value for control (nontreated) foals, treatment with ivermectin, pyrantel, and oxibendazole was 98.2, 74.2, and 44.5% effective, respectively, when administered 28 days after experimentally induced infection with P equorum. Adverse reactions attributable to treatment were not observed.

Free access
in Journal of the American Veterinary Medical Association



Determine the effect of sample holding time and single sample reuse on viscoelastic coagulation parameters when using fresh equine native whole blood.


8 healthy adult horses from a university teaching herd.


Blood collected by direct jugular venipuncture (18 ga needle, 3 mL syringe) was held at 37 °C for 2, 4, 6, or 8 minutes according to 1 of 2 protocols. Syringes were gently inverted twice, a small amount of blood was expressed, testing cartridges were filled, and placed within the VCM-Vet™ device (Entegrion Inc). Protocol A: samples were processed from a single syringe. Protocol B: 4 syringes were drawn through a single needle. VCM-Vet™ measures assessed included clot time (CT), clot formation time (CFT), alpha angle (AA), amplitude at 10/20 minutes (A10/A20), maximal clot firmness (MCF), and lysis index at 30/45 minutes (LI30/LI45). Differences over time were examined using the Friedman test and post hoc Wilcoxon Rank Sum Test with Bonferroni correction, P ≤ .05.


Following Protocol A, there was a significant effect of holding time for CT (P = .02), CFT (P = .04), and AA (P = .05). CT and AA decreased over time, while CFT increased. Samples handled by Protocol B showed no significant difference over time for any of the VCM-Vet™ parameters.


Sample holding time and handling protocol impact VCM-Vet™ testing results of fresh equine native whole blood. Viscoelastic coagulation samples tested using the VCM-Vet™ may be held unagitated for up to 8 minutes after collection while warm, but should not be reused.

Open access
in American Journal of Veterinary Research