Infrared Thermography as a Diagnostic Tool for the Assessment of Mastitis in Dairy Ruminants

Abstract

Among the health issues of major concern in dairy ruminants, mastitis stands out as being associated with considerable losses in productivity and compromised animal health and welfare. Currently, the available methods for the early detection of mastitis are either inaccurate, requiring further validation, or expensive and labor intensive. Moreover, most of them cannot be applied at the point of care. Infrared thermography (IRT) is a rapid, non-invasive technology that can be used in situ to measure udder temperature and identify variations and inconsistencies thereof, serving as a benchmarking tool for the assessment of udders' physiological and/or health status. Despite the numerous applications in livestock farming, IRT is still underexploited due to the lack of standardized operation procedures and significant gaps regarding the optimum settings of the thermal cameras, which are currently exploited on a case-specific basis. Therefore, the objective of this review paper was twofold: first, to provide the state of knowledge on the applications of IRT for the assessment of udder health status in dairy ruminants, and second, to summarize and discuss the major strengths and weaknesses of IRT application at the point of care, as well as future challenges and opportunities of its extensive adoption for the diagnosis of udder health status and control of mastitis at the animal and herd levels.

Keywords: diagnosis; infrared thermography; mastitis; ruminants; thermal imaging; udder temperature.

Figure 1

Illustration of thermal imaging for the management of cow’s udder health.

Figure 2

Thermal images of a cow udder. Lateral (A) and caudal (B) view of the udder. Images were taken using FLIR E8-XT (FLIR Systems Inc., Wilsonville, Oregon, USA), which displays a 320 × 240 resolution (source: Laboratory of Anatomy and Physiology of Farm Animals, Agricultural University of Athens).

Figure 3

Thermal image of a sheep suffering from gangrenous mastitis (A). The left udder half (a) has been necrotized, while the right udder half (b) displays an increased temperature. Thermogram of a sheep udder with chronic mastitis (B); both udder halves (c,d) are fibrotic. Udders with acute clinical mastitis exhibit higher temperatures compared to chronic cases. Images A and B were taken on the same day and time using FLIR E8-XT (FLIR Systems Inc., Wilsonville, Oregon, USA) at a 320 × 240 resolution (source: Laboratory of Anatomy and Physiology of Farm Animals, Agricultural University of Athens).

Figure 4

Thermal image of an unhealthy goat udder (A). The left udder half is severely asymmetric and fibrotic (a). Thermal image of a goat udder with an abscess (B). The abscess (b) is located on the udder cleft and displays a higher temperature compared to the rest of the udder. Images were taken using FLIR E8-XT (FLIR Systems Inc., Wilsonville, Oregon, USA), which displays a 320 × 240 resolution (source: Laboratory of Anatomy and Physiology of Farm Animals, Agricultural University of Athens).