Effect of parenteral administration of erythromycin, tilmicosin, and tylosin on abomasal emptying rate in suckling calves.
OBJECTIVE
To determine the effect of parenteral administration of erythromycin, tilmicosin, and tylosin on abomasal emptying rate in suckling calves.


METHODS
8 male Holstein-Friesian calves < 35 days old.


METHODS
Calves received each of 4 treatments in random order (2 mL of saline [0.9% NaCl] solution, IM [control treatment]; erythromycin, 8.8 mg/kg, IM; tilmicosin, 10 mg/kg, SC; and tylosin, 17.6 mg/kg, IM). Calves were fed 2 L of milk replacer containing acetaminophen (50 mg/kg) 30 minutes later. Jugular venous blood samples and transabdominal ultrasonographic abomasal dimensions were obtained periodically after suckling. Abomasal emptying rate was assessed on the basis of the time to maximal plasma acetaminophen concentration and ultrasonographic determination of the halftime of abomasal emptying. One-tailed Dunnett post tests were conducted whenever the F value for group was significant.


RESULTS
Emptying rate was faster for erythromycin, tilimicosin, and tylosin than for the control treatment, as determined on the basis of time to maximal plasma acetaminophen concentration. Ultrasonography indicated that the half-time of abomasal emptying was significantly shorter for erythromycin than for the control treatment. Tylosin and tilmicosin accelerated the abomasal emptying rate, but not significantly, relative to the emptying rate for the control treatment.


CONCLUSIONS
Administration of erythromycin, tilmicosin, and tylosin at the label dosage increased abomasal emptying rate in calves. The clinical importance of an increase in abomasal emptying rate in cattle remains to be determined.
Nouri
Mohammad
M
Department of Veterinary Clinical Sciences, University of Illinois at Urbana-Champaign, IL 62801, USA.
Constable
Peter D
PD
D000018:Abomasum / Q000187:drug effects* / Q000502:physiology; D000082:Acetaminophen / Q000493:pharmacokinetics; D000818:Animals; D000833:Animals, Suckling; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000493:pharmacokinetics; D002417:Cattle; D018592:Cross-Over Studies; D004917:Erythromycin / Q000008:administration & dosage* / Q000494:pharmacology; D005746:Gastric Emptying / Q000187:drug effects* / Q000502:physiology; D018942:Macrolides / Q000008:administration & dosage* / Q000494:pharmacology; D013997:Time Factors; D015645:Tylosin / Q000008:administration & dosage* / Q000031:analogs & derivatives* / Q000494:pharmacology
D000900:Anti-Bacterial Agents; D000894:Anti-Inflammatory Agents, Non-Steroidal; D018942:Macrolides; D000082:Acetaminophen; D004917:Erythromycin; C052319:tilmicosin; D015645:Tylosin