Effect of danofloxacin and tilmicosin on body temperatures of beef calves with pneumonia experimentally induced by inoculation with Mannheimia haemolytica.
OBJECTIVE
To examine effects of danofloxacin and tilmicosin on continuously recorded body temperature in beef calves with pneumonia experimentally induced by inoculation of Mannheimia haemolytica.


METHODS
41 Angus-cross heifers (body weight, 160 to 220 kg) without a recent history of respiratory tract disease or antimicrobial treatment, all from a single ranch.


METHODS
Radiotransmitters were implanted intravaginally in each calf. Pneumonia was induced intrabronchially by use of logarithmic-phase cultures of M. haemolytica. At 21 hours after inoculation, calves were treated with saline (0.9% NaCl) solution, danofloxacin, or tilmicosin. Body temperature was monitored from 66 hours before inoculation until 72 hours after treatment. Area under the curve (AUC) of the temperature-time plot and mean temperature were calculated for 3-hour intervals and compared among treatment groups.


RESULTS
The AUCs for 3-hour intervals did not differ significantly among treatment groups for any of the time periods. Analysis of the mean temperature for 3-hour intervals revealed significantly higher temperatures at most time periods for saline-treated calves, compared with temperatures for antimicrobial-treated calves; however, we did not detect significant differences between the danofloxacin- and tilmicosin-treated calves. The circadian rhythm of temperatures before exposure was detected again approximately 48 hours after bacterial inoculation.


CONCLUSIONS
Danofloxacin and tilmicosin did not differ in their effect on mean body temperature for 3-hour intervals but significantly decreased body temperature, compared with body temperature in saline-treated calves. Normal daily variation in body temperature must be considered in the face of respiratory tract disease during clinical evaluation of feedlot cattle.
Fajt
Virginia R
VR
Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA 50010-3020, USA.
Apley
Michael D
MD
Brogden
Kim A
KA
Skogerboe
Terry L
TL
Shostrom
Valerie K
VK
Chin
Ya-Lin
YL
D000818:Animals; D001831:Body Temperature / Q000187:drug effects*; D002417:Cattle; D002418:Cattle Diseases / Q000503:physiopathology*; D002940:Circadian Rhythm / Q000502:physiology; D024841:Fluoroquinolones / Q000494:pharmacology*; D018942:Macrolides / Q000494:pharmacology*; D016978:Mannheimia haemolytica; D012766:Pasteurellosis, Pneumonic / Q000503:physiopathology*; D011014:Pneumonia / Q000503:physiopathology / Q000662:veterinary*; D013686:Telemetry / Q000295:instrumentation / Q000662:veterinary; D015645:Tylosin / Q000031:analogs & derivatives* / Q000494:pharmacology*
D024841:Fluoroquinolones; D018942:Macrolides; C068581:danofloxacin; C052319:tilmicosin; D015645:Tylosin