Infrared Thermography as a Non-Invasive Diagnostic Tool in the Veterinary Field
Amit Kumar*, Naveen Kumar, and Sandeep Saharan
Department of Veterinary Surgery and Radiology
Department of Veterinary Public Health and Epidemiology
Lala Lajpat Rai University of Veterinary and Animal Science, Hisar (Haryana), India-125004
Corresponding author: Amit Kumar, amitdhartterwal@gmail.com
ABSTRACT
Infrared thermography (IRT) presents promising possibilities as a diagnostic approach for detecting diseases in animals. By utilizing infrared radiation, IRT captures temperature images of an object without the need for invasive procedures. This technique can effectively identify health problems in animals by detecting deviations in their body temperature. In both human and veterinary medicine, infrared thermography has proven to be effective in a wide range of applications. In the context of farm animals, IRT cameras have been utilized for multiple purposes, including early detection of estrus, diagnosing mastitis, identifying viral diarrhoea infections in calves, detecting foot-and-mouth diseases in cattle, and evaluating the milking process. A key advantage of IRT is its capability to remotely assess temperature distribution, eliminating the necessity for direct physical contact with the monitored surface.
Keywords: Infrared, Thermography, Veterinary
INTRODUCTION
Infrared thermography (IRT) is a non-invasive technique that measures emitted infrared radiation and presents the data as a thermogram, a visual representation of surface temperature (Eddy et al., 2001). All objects emit heat radiation in the infrared spectrum, and the intensity and distribution of this radiation depend on the object’s temperature and surface properties. By using specialized thermographic cameras capable of detecting infrared radiation, even subtle temperature changes can be accurately monitored. The collected data is processed by computers and displayed as temperature maps, providing a detailed analysis of the temperature distribution. IRT has found applications in various fields, including industry, human medicine, and veterinary medicine, primarily for diagnostic purposes. In veterinary medicine, thermography is particularly useful for diagnosing lameness problems in horses, as it allows non-invasive assessment of inflammatory changes (Turner, 1991). It provides detailed information about the neurological system, circulatory system, muscles, skeleton, and local inflammatory processes. Early detection and treatment of lameness can alleviate pain and improve the chances of recovery, thereby restoring the economic value of the animal (Leach et al., 2012). Thermography has also been recommended as a valuable method for studying thermoregulation (Spruyt et al., 1995). This technique is effective in detecting early signs of health issues, including inflammation, infection, and injuries. Infrared thermography has demonstrated successful applications in both human and veterinary medicine. Within the domain of farm animals, IRT cameras have been utilized for various purposes, including early detection of estrus (Hurnik et al., 1985), identification of mastitis (Berry et al., 2003), detection of viral diarrhoea infections in calves (Schaefer et al., 2007), diagnosis of foot-and-mouth disease in cattle (Rainwater-Lovett et al., 2009), and evaluation of the milking process (Kunc et al., 2007). These studies highlight the diverse applications and effectiveness of infrared thermography in the field of veterinary medicine. Changes in temperature are indicative of abnormal conditions, with areas of inflammation showing increased temperature due to enhanced blood flow, while areas with decreased blood supply, such as wounds, may exhibit decreased temperature. Additionally, IRT can be used for monitoring herd health, determining optimal breeding times, and even detecting pregnancy. A significant advantage of this method is its non-contact nature, allowing for remote temperature readings without physical contact with the surface being monitored (Speakman and Ward, 1998). Thermography serves as an excellent complement to clinical examination and other imaging techniques like radiology, ultrasonography, and scintigraphy. In summary, infrared thermography is a valuable diagnostic tool for identifying and monitoring health conditions in animals. It provides a non-invasive and efficient method for early detection of diseases, enabling prompt intervention and treatment.
Diagnostic applications of IRT:
- Mastitis:
Infrared thermography (IRT) is a non-invasive technique that can be employed as a diagnostic tool for early detection of subclinical mastitis in dairy cows. Through the use of a highly sensitive thermal camera, IRT is capable of identifying subtle alterations in udder temperature caused by physiological changes during both subclinical and clinical mastitis. Research has demonstrated the potential of IRT for diagnosing diseases in bovine species, and it offers a rapid and safe means of detecting mastitis by measuring localized temperature increases resulting from inflammatory reactions even prior to the manifestation of visible symptoms (Stelletta et al., 2012). The early detection of subclinical mastitis using IRT can be beneficial for diagnosing the infection, determining the causative agent, and implementing effective management strategies. Therefore, infrared thermography exhibits promise as a suitable tool for the early identification and screening of mastitis in dairy cattle.
- Lameness and foot diseases:
Claw abnormalities are responsible for the majority of lameness cases in animals. Several studies have indicated that approximately 90% of lameness incidents are associated with claw diseases, with 76% to 84% of foot lesions occurring in the hind limbs (Murray et al., 1996). While regular claw trimming is an effective management practice for preventing claw diseases and identifying and treating lesions, exploring alternative methods to assess claw disorders is crucial. One potential approach is the use of infrared thermography (IRT) to evaluate claw health. The presence of increased hoof temperature during the onset of lameness suggests a vascular component. Bargai et al. (1992) found that laminitis, which is a diffuse aseptic foot inflammation, leads to elevated hoof temperature. IRT can detect such temperature changes, enabling early diagnosis and intervention for effective treatment of the condition.
- Monitoring of heat stress:
Heat stress in animals typically triggers homeostatic responses, such as an elevation in respiration rate, body temperature, and water consumption, while reducing food intake (Gupta et al., 2013; Caulfield et al., 2014). Infrared thermography (IRT) presents a valuable tool for detecting temperature changes on the animal’s skin, enabling farmers to effectively monitor and manage heat stress in their animals.
- Monitoring of Oestrus and Pregnancy detection
The infrared thermography (IRT) technique provides a non-invasive means of detecting changes in surface temperature from a safe distance, offering enhanced efficiency in detecting estrus-related thermal changes compared to conventional methods. Moreover, IRT is cost-effective and easily implementable under farm conditions (McManus et al., 2016). Several studies have examined the use of IRT for estrus detection in dairy animals, validating its effectiveness (Nääs et al., 2020). By detecting even subtle temperature changes, IRT cameras prove to be highly capable in capturing these surface temperature variations associated with reproductive physiological events in animals. The computer-assisted automation of IRT systems, particularly, holds promise in generating estrus alerts and has the potential to become a valuable addition to the repertoire of estrus detection techniques. In addition, infrared thermography can be employed to monitor pregnant goats by tracking changes in body temperature throughout pregnancy. Notably, an increase in temperature in the udder and abdominal region can indicate pregnancy, while a subsequent decrease in temperature may indicate the onset of labour. Overall herd health: Infrared thermography can be used to monitor the overall health of a goat herd. By detecting early signs of illness or injury, farmers and veterinarians can take prompt action to prevent the spread of disease and ensure the health and well-being of the entire herd.
CONCLUSION
Infrared thermography provides a non-invasive approach to assessing essential parameters in animals without the need for physical contact. This feature minimizes stress and ensures the welfare of the animals during the assessment process. Moreover, this technique is user-friendly, easy to operate, and has lower operating costs. Infrared thermography finds applications in various industrial operations and serves as a diagnostic tool in medical and veterinary practices. In the context of dairy animal farming, this technology has proven effective in diagnosing heat stress, mastitis, postpartum diseases, and lameness. It has also been utilized to assess feed intake and reproductive status in livestock. The adoption of infrared thermography in livestock farming is regarded as an advanced, sensitive, cost-effective, rapid, and non-invasive technique that eliminates the need for stressful physical interaction with animals.
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