Abstract:

Duration of effectiveness of tulathromycin injectable solution in an Actinobacillus pleuropneumoniae respiratory-disease challenge model in swine

Terri A. Waag, BS; James R. Bradford, DVM, Diplomate ABVP; Merlyn J. Lucas, DVM, MS, Diplomate ACT; Kathleen A. Rooney, MS, DVM; Robert G. Nutsch, DVM, MS, MBA; Kelly F. Lechtenberg, DVM, PhD; Clark D. Smothers, PhD

Complete article is available online.

PDF version is available online.

Objective: To evaluate the duration of effectiveness of a single intramuscular injection of tulathromycin in a swine respiratory-disease challenge model using intranasal inoculation of Actinobacillus pleuropneumoniae serotype 5.

Materials and methods: Two hundred and forty female and castrated-male crossbred pigs were randomly assigned to six treatment groups and housed in 20 pens of 12 pigs per pen (two pigs per treatment per pen). On each of Days -11, -9, -7, -5, and -3, two pigs per pen were administered tulathromycin intramuscularly at 2.5 mg per kg body weight. Pigs assigned to the control group received no treatment. On Day 0, all pigs were challenged intranasally with highly virulent A pleuropneumoniae serotype 5. Each pig was assessed for general health and evaluated for abnormal respiration and attitude 9 hours post inoculation and at least daily until trial termination (Day 7). Necropsies were performed on pigs that died or were euthanized and on all surviving pigs on Day 7.

Results: With the exception of Day -11, pig removal rates (death and euthanasia) in the tulathromycin groups were significantly less than in the control group (P < .05). Additionally, the weighted percentages of total lung lesions for pigs administered tulathromycin on Days -5 (16.8%) and -3 (10.5%) were significantly less than that of the control group (27.5%; P < .05)

Implication: A single intramuscular dose of tulathromycin may provide up to 9 days of protection against death and severe morbidity caused by A pleuropneumoniae in pigs.

Keywords: Actinobacillus pleuropneumoniae, tulathromycin, removals, lung lesions, APP

RIS citationCite as: Waag TA, Bradford JR, Lucas MJ, et al. Duration of effectiveness of tulathromycin injectable solution in an Actinobacillus pleuropneumoniae respiratory-disease challenge model in swine. J Swine Health Prod 2008;16(3):126-130.

Search the AASV web site for pages with similar keywords.