Infrared thermography: an assistant tool in the diagnosis and prognosis of mastitis in sheep
ABSTRACT. Nogueira F.R.B., Sousa B.B., de Carvalho M. das G.X., Garino Junior F., Marques A.V.M.S. & Leite R.F. [Infrared thermography: an assistant tool in the diagnosis and prognosis of mastitis in sheep]. Termografia infravermelha: uma ferramenta para auxiliar no diagnóstico e prognóstico de mastite em ovelha. Revista Brasileira de Medicina Veterinária, 35(3):289-297, 2013. Instituto Federal de Educação Ciência e Tecnologia da Paraíba, Rua Presidente Tancredo Neves, s/n, Jardim Sorrilândia, Sousa, PB 58800-970, Brasil. E-mail: firstname.lastname@example.org The production of knowledge about mastitis in sheep is an immediate necessity to base prevention, treatment and control strategies or programs. In order to do so, it is required to develop easy-to-adopt diagnosis techniques and procedures to be used in field. Infrared thermography (IRT) is pointed in some dairy cattle mastitis studies as a tool which presents these characteristics. Considering the positive results produced by IRT, the present work is aimed at studying it as assistant tool in the diagnosis and prognosis of mastitis in sheared sheep. It was evaluated 49 sheep of the breeds Santa Inês, Dorper, or crossbreed resulting from both. A total of 98 half mammary gland was clinically evaluated, using as reference symmetry, consistency, existence of nodules, and milk aspect. It was also performed the California Mastitis Test (CMT) and microbiological test of milk secretions. Thermographic images were obtained from 06h30 to 07h30, with animals resting in the shadow. The average temperature and humidity index (THI) at that time was 68.9. Gland superficial temperatures (GST) obtained from thermographic images were 34.28ºC(±1.2674), 33.04ºC(±1.4423), and 33.8ºC(±1.1126) in the healthy halves, with clinical mastitis, and subclinical mastitis, respectively. GST also presented some significant variation due to alterations in the consistency of the clinically diseased tissue, thus indicating several stages in the inflammatory process. Halves with decreased consistency and small nodules presented lower average values of 30.1ºC(±0.708) and 32.7ºC(±1.379), followed by increased consistency 33.5ºC(±1.407), large nodule 33.9ºC(±1.056), with no alteration 33.9ºC(±1.168), and medium nodule 34.1ºC(±0.340). Associated with other techniques such as clinical exams, IRT has great potential to be an assistant tool in the diagnosis and prognosis of mastitis in sheep, and it may help in taking decisions and adopting herd management practices.