Prior to injection, a tourniquet is placed around the fetlock to help keep the contrast material within the foot during radiography. Diffusion of contrast may make some areas appear hypoperfused, falsely increasing the apparent severity of the laminitic episode. After injection of the contrast material, films are taken within 45 seconds to avoid artifact caused by diffusion. Evaluation of blood supply to several areas of the foot allows the practitioner to distinguish mild, moderate, and severe compromise of the hoof, chronic laminitis, and sinking. Other diagnostics
Other imaging tools have been used to show mechanical deviations in laminitis cases include computed tomography, as well as MRI, which also provides some physiologic information. Nuclear scintigraphy may also be useful in certain situations. Ultrasonography has been explored as a way to quantify changes in bloodflow to the foot. Prognosis
The sooner the diagnosis is made, the faster the treatment and the recovery process can begin. Rapid diagnosis of laminitis is often difficult, since the general problem often starts somewhere else in the horses body. With modern therapies, most laminitics will be able to bear a rider or completely recover, if treated quickly, and if the laminitis was not severe or complicated (e.g. by equine metabolic syndrome or Cushings disease). Even in these cases, a clinical cure can often be achieved. Endotoxic laminitis (e.g. after foaling) tends to be more difficult to treat. Successful treatment requires a competent farrier and veterinarian, and success is not guaranteed.
There were several competing early theories of pain among the ancient Greeks: Hippocrates believed that it was due to an imbalance in vital fluids. In the 11th century, Avicenna theorized that there were a number of feeling senses including touch, pain and titillation. In 1644, René Descartes theorized that pain was a disturbance that passed along nerve fibers until the disturbance reached the brain. Descartess work, along with Avicennas, prefigured the 19th-century development of specificity theory. Specificity theory saw pain as "a specific sensation, with its own sensory apparatus independent of touch and other senses". Another theory that came to prominence in the 18th and 19th centuries was intensive theory, which conceived of pain not as a unique sensory modality, but an emotional state produced by stronger than normal stimuli such as intense light, pressure or temperature. By the mid-1890s, specificity was backed mostly by physiologists and physicians, and the intensive theory was mostly backed by psychologists. However, after a series of clinical observations by Henry Head and experiments by Max von Frey, the psychologists migrated to specificity almost en masse, and by centurys end, most textbooks on physiology and psychology were presenting pain specificity as fact. Modern
Some sensory fibers do not differentiate between noxious and non-noxious stimuli, while others, nociceptors, respond only to noxious, high intensity stimuli. At the peripheral end of the nociceptor, noxious stimuli generate currents that, above a given threshold, send signals along the nerve fiber to the spinal cord.