What tool is commonly used to assess lameness in horses?

A radiograph, commonly known as an X-ray, is an essential tool for assessing lameness in horses because it provides a detailed view of the internal structure of bones and joints. When a horse exhibits signs of lameness, it is crucial to determine whether there are any underlying skeletal issues, such as fractures, bone spurs, or joint abnormalities. A radiograph allows veterinarians to visualize these conditions, facilitating accurate diagnosis and appropriate treatment plans.

While other tools listed can provide valuable information in different contexts – a stethoscope is primarily used for auscultating heart and lung sounds, an ultrasound machine is useful for imaging soft tissues such as muscles and tendons, and a thermal camera can detect variations in temperature that may indicate inflammation – they do not offer the same level of detail regarding bone structure and integrity that radiographs provide. Thus, when it comes to identifying specific causes of lameness that involve the skeletal system, radiographs are the standard diagnostic tool.