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ARS Home » Research » Publications at this Location » Publication #108872
Title: THE EFFECTS OF DANOFLOXACIN AND TILMICOSIN ON NEUTROPHIL FUNCTION AND LUNG CONSOLIDATION IN BEEF CALVES WITH INDUCED PASTEURELLA PNEUMONIA

Author
item FAJT, VIRGINIA - IA STATE UNIV., AMES, IA
item APLEY, MICHAEL - IA STATE UNIV., AMES, IA
item ROTH, JAMES - IA STATE UNIV., AMES, IA
item FRANK, DAGMAR - IA STATE UNIV., AMES, IA
item BROGDEN, KIM
item SKOGERBOE, TERRY - PFIZER ANIM. HEALTH, MO
item KARLE, VALERIE - PFIZER ANIM. HEALTH, MO
item DAYTON, ARTHUR - PFIZER ANIM. HEALTH, MO

Submitted to: Journal of Veterinary Pharmacology and Therapeutics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/20/2003
Publication Date: 6/20/2003
Citation: FAJT, V.R., APLEY, M.D., ROTH, J.A., FRANK, D.E., BROGDEN, K.A., SKOGERBOE,T.L., SHOSTROM, V.K., Chin, Y.L. THE EFFECTS OF DANOFLOXACIN AND TILMICOSIN ON NEUTROPHIL FUNCTION AND LUNG CONSOLIDATION IN BEEF HEIFER CALVES WITH INDUCED PASTEURELLA (MANNHEIMIA) HAEMOLYTICA PNEUMONIA. JOURNAL OF VETERINARY PHARMACOLOGY AND THERAPEUTICS. 2003. v. 26(3). p.173-179.

Interpretive Summary: Respiratory tract diseases are a leading cause of loss from disease in the cattle, sheep, and goat industries. Annual loss in the United States is estimated to exceed one billion dollars. Losses are from mortality, reduced feed efficiency, and slaughter condemnations, as well as prevention and treatment measures. Currently, not all the factors leading to the development of pneumonia are known by scientists and veterinarians. As part of our ongoing studies to understand the disease process, Pasteurella pneumonia was induced in weaned beef heifer calves, approximately 6 months of age. Calves were treated at 20 hours after challenge with therapeutic doses of danofloxacin or tilmicosin, and the ex-vivo effects on circulating neutrophil function, neutrophil apoptosis, and hematological parameters were examined, as was the effect on percent lung consolidation. There were no significant differences for any of the neutrophil function assays or neutrophil apoptosis among the challenged-treated groups. There were also no significant differences in percent lung consolidation among the challenged-treated groups. This suggests that danofloxacin and tilmicosin have no clinical significant effects on neutrophil function or apoptosis. Corollary benefits include an increase in the profitability and international competitiveness of the U. S. cattle industry, a stronger rural economy, and a continued supply of inexpensive, wholesome beef and beef products for the American consumer.

Technical Abstract: Pasteurella pneumonia was induced in weaned beef heifer calves, approximately 6 months of age. Calves were treated at 20 hours after challenge with therapeutic doses of danofloxacin or tilmicosin, and the ex-vivo effects on circulating neutrophil function, neutrophil apoptosis, and hematological parameters were examined, as was the effect on percent lung consolidation. Neutrophils were collected at 3, 24 and 48 hours after treatment. Neutrophil function assays included: random migration under agarose, cytochrome C reduction, iodination, Staphylococcus aureus ingestion, chemotaxis, and antibody-dependent and antibody-independent cell-mediated cytotoxicity assay. Apoptosis was determined using a cell death detection kit. Euthanasia was performed at 72 hours after treatment. Statistical comparisons were made among the 3 groups of challenged-treated animals: saline-, danofloxacin-, and tilmicosin-treated animals. Comparisons were also made between non-challenged, non-treated animals (NTX) and challenged saline-treated animals. There were no significant differences for any of the neutrophil function assays or neutrophil apoptosis among the challenged-treated groups. There were also no significant differences in percent lung consolidation among the challenged- treated groups. This suggests that danofloxacin and tilmicosin have no clinical significant effects on neutrophil function or apoptosis. Significant differences were found between the NTX calves and the challenged non-treated calves in several neutrophil assays, which were attributed to an effect of the Pasteurella infection.