Florfenicol Therapy During Natural Mannheimia haemolytica Infection in Sakiz Sheep

Acta Scientiae Veterinariae

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Site: http://www.ufrgs.br/actavet/
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ISSN: 16799216
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Início Publicação: 31/12/1969
Periodicidade: Trimestral
Área de Estudo: Medicina Veterinária

Florfenicol Therapy During Natural Mannheimia haemolytica Infection in Sakiz Sheep

Ano: 2011 | Volume: 39 | Número: 2
Autores: Kerem Ural, Bulent Ulutas, Sukru Kirkan, Mehmet Gultekin, Ugur Parin
Autor Correspondente: Kerem Ural | [email protected]

Palavras-chave: mannheimia haemolytica, sheep, respiratory disease, florfenicol, sakiz breed

Resumos Cadastrados

Resumo Inglês:

Background: Bronchopneumonia caused by Mannheimia haemolytica affects sheep of all ages worldwide and may be devastating
especially in young animals undergone recent stress (i.e. transportation, weaning, mixing with animals from different farms. It is
a common cause of morbidity and mortality in lambs and kids, especially in those that have not received adequate colostrum or
in which passive colostral immunity is waning. Yearly herd losses costing millions of dollars have led to research focused on
theurapeutic trials and vaccine production because of various strains isolated demonstrating the continuing economic importance
of Mannheimia haemolytica infection. A field trial was performed under commercial sheep farm located in Western Turkey,
Aydin in an attempt to investigate the efficacy of an injectable formulation of florfenicol against naturally occuring Mannheimia
haemolytica.
Materials, Methods & Results: A total of 27 Sakiz breed lambs at the age of 36–60 days old, of both sexes, with naturally
occuring M. haemolytica infection were included in the present study. Prior to allocation into groups, a detailed clinical examination
carried out in all the lambs, revealed a variety of abnormal findings: coughing, presence of nasal and ophthalmic discharge,
increased respiratory rate and rectal temperature and abnormal sounds at lung auscultation. A total of 27 samples taken from
transtracheal aspiration bronchoalveolar fluid in the Sakiz breed lambs were taken into sterile containers in an attemp to perform
isolation and identification of Mannheimia haemolytica. The antibiotic susceptibility tests for Mannheimia haemolytica
strains isolated from transtracheal aspiration bronchoalveolar fluid were carried out by disc diffusion as described previously.
On days 0, 1, 7, 15 and 30 sheeps were given a clinical score. The clinical lesion score (scores from 0 to 3) was derived from the
clinical signs (feed consumption oral and nasal discharges, coughing lung auscultation findings, complete clinical examination)
and was carried out by an investigator blinded. The lambs were randomly allocated into 2 groups until the required number of
lambs in each group was reached. Lambs in group F (n = 17) were subcutaneoulsy injected with a single dose of florfenicol
(dosage 2 mg/kg bodyweight); lambs in group C (n = 10) did not receive an antibiotic treatment and were left as controls. The
efficacy of florfenicol was assessed clinically and on the basis of a lesion score derived from the physical examination. Throughout
the study florfenicol treatment significantly decreased (P < 0.01) the investigator’s clinical scores while no significant changes
were detected in the untreated control group.
Discussion: M. haemolytica is a commonly recognized responsible agent for respiratory diseases in sheep and several therapeutic
antibiotics have been suggested for treatment applications. Florfenicol, that might have the potential of efficacy against M.
haemolytica has not been used in sheep, therfore there is lack of data regarding its efficacy and safety. Despite the efficacy of
the drug against respiratory infections of calves and pigs has been documented. Besides bioavailability and pharmacokinetics
of florfenicol was evaluated solely in healthy sheep. Based on clinical scoring and complete remission, and supporting laboratory
signs involving antibiogram studies, results of the present study may indicate that florfenicol may be a good and safe choice for
treatment of respiratory infections due to M. haemolytica. The present results were supported by the gradual improvement and
alleviation of clinical signs and, clinical remission within description of scores and the absence of pathogenic organisms in
transtracheal aspiration after treatment. Furthermore, florfenicol-treated lambs had a significantly better clinical improvement and
cure that that of untreated control group of animals.