Search Results
You are looking at 1 - 3 of 3 items for
- Author or Editor: Lealon V. Tonkinson x
- Refine by Access: All Content x
Abstract
Objective
To determine and evaluate the efficacy of the dose range of tilmicosin phosphate fed to pigs for control of pneumonia attributable to Actinobacillus pleuropneumoniae during episodes of clinical disease in commercial herds.
Design
12 trials were run in 9 geographic locations in herds with a history of pneumonia caused by A pleuropneumoniae.
Animals
Clinically normal male and female pigs of various body weights.
Procedure
Two doses of tilmicosin phosphate (200 and 400 µg/g) and a 0 dose were administered in the feed for 21 days. Variables for determining efficacy were daily independent composite clinical impression score, individual pig weight, mortality, percentage of pneumonic involvement, and frequency of isolation of bacterial pathogens.
Results
Medicated pigs had significantly lower mortality attributed to pneumonia than did nonmedicated pigs. In trials with confirmed pneumonia caused by A pleuropneumoniae or Pasteurella multocida, weight gain, feed conversion, and clinical impression scores were significantly improved in the pigs receiving 200 or 400 µg/g of tilmicosin, compared with nonmedicated pigs.
Conclusions
The clinical field trials reported here confirm that tilmicosin in the feed at 200 µg/g is effective for control of swine pneumonia attributable to A pleuropneumoniae or P multocida.
Clinical Relevance
Under the moderate natural challenge conditions encountered, tilmicosin at 400 µg/g was not different from tilmicosin at 200 µg/g.
Summary:
The prophylactic administration of injectable tilmicosin for pneumonia in weaned beef calves was investigated in 1,806 animals. Comparisons were made among calves receiving an “on-arrival” injection of tilmicosin, calves receiving a single injection of long-acting oxytetracycline, and calves receiving no prophylaxis. Morbidity and mortality attributable to pneumonia, morbidity and mortality attributable to all causes, and case fatality were significantly lower in the group of calves that received tilmicosin, compared with calves that received long-acting oxytetracycline and calves that received no prophylactic antibiotic. Mean time to initial pneumonia treatment was significantly extended in calves that received prophylaxis, compared with those that received no antibiotic on arrival at the feedlot. Calves that received tilmicosin gained significantly more weight than calves that received oxy tetracycline. Calves that were not treated for pneumonia during the trial period gained significantly more weight than did those calves that were treated for pneumonia regardless of experimental group.
The majority of mortalities were attributable to fibrinous pneumonia (31/34). Important bacterial isolates (Pasteurella spp, Haemophilus somnus, Actinomyces pyogenes) obtained at necropsy did not have resistance to tilmicosin in association with administration of tilmicosin as prophylaxis for pneumonia. However, bacterial resistance to trimethoprim/sulfonamide and to oxytetracycline were commonly found in these postmortem isolates.
Abstract
Objective
To determine the effective dosage of tilmicosin phosphate when fed to pigs for the control of pneumonia attributable to Actinobacillus pleuropneumoniae.
Design
Randomized complete block design, with initial weight as the blocking factor.
Animals
Seeder pigs were used to infect clinically normal male and female pigs weighing between 13.6 and 36.3 kg at each of 4 trials.
Procedure
Five doses of tilmicosin phosphate (0, 100, 200, 300, and 400 µg/g) were fed to pigs for 21 days. Pigs received experimental feeds 7 days before the seeder pigs were placed into pens. Feeding continued for an additional 14 days, with seeder pigs removed 3 to 8 days after placement. All pigs were euthanatized and necropsied, with lung bacterial flora and percentages of pneumonic involvement determined.
Results
Improvement in clinical impression score, daily rectal temperature, and weight gain were seen for all doses of tilmicosin, compared with controls. For the same variables, tilmicosin administered at 200 to 400 µg/g resulted in improvements over the 100 µg/g dose.
Conclusions
Data indicate that tilmicosin phosphate fed to pigs at 200 to 400 µg/g is effective in controlling and preventing A pleuropneumoniae-induced pneumonia, when administered in feed for 21 days.
