Comparison of tilmicosin with long-acting oxytetracycline for treatment of respiratory tract disease in calves.
OBJECTIVE
To compare the effect of a single parenteral injection of tilmicosin with that of a single dose of a long-acting oxytetracycline as treatment in the early stages of naturally acquired undifferentiated respiratory tract disease in young dairy calves.


METHODS
Prospective clinical trial, randomized block design.


METHODS
40 dairy calves.


METHODS
78 calves from 5 farms were examined weekly until 3 months old. When respiratory tract disease was diagnosed by a veterinarian, the calf was assigned to 1 or 2 treatment groups. Transtracheal wash samples were acquired to characterize the pathogens. The veterinarian, who was unaware of treatment assignments, examined calves for 3 days after treatment and evaluated severity, using a scoring system. Growth rates were measured.


RESULTS
On the basis of response to initial treatment, relapse rates, and effect on growth rates, the antibiotics were determined to be equally effective. Severity of clinical disease was significantly (P < 0.03) less for the tilmicosin-treated calves on days 2 and 3 after treatment. Findings from analysis of transtracheal wash samples indicated Pasteurella multocida (25/40), P haemolytica (4/40), Haemophilus somnus (4/40), Actinomyces pyogenes (3/40), and Aspergillus sp (2/40). Mycoplasma was isolated in association with bacterial isolates in 22 calves.


CONCLUSIONS
Tilmicosin and oxytetracycline are effective in treatment of respiratory tract disease in young calves, even when Mycoplasma spp are involved. Tilmicosin is more effective in resolving clinical signs. Early treatment of dairy calves with respiratory tract disease may decrease detrimental effects on growth.
Musser
J
J
Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853-6401, USA.
Mechor
G D
GD
Gröhn
Y T
YT
Dubovi
E J
EJ
Shin
S
S
D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D002417:Cattle; D002418:Cattle Diseases / Q000188:drug therapy*; D018942:Macrolides; D010118:Oxytetracycline / Q000008:administration & dosage / Q000627:therapeutic use*; D012140:Respiratory Tract Diseases / Q000188:drug therapy / Q000662:veterinary*; D015645:Tylosin / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use
D000900:Anti-Bacterial Agents; D018942:Macrolides; D010118:Oxytetracycline; C052319:tilmicosin; D015645:Tylosin