Significance, diagnosis and interpretation of pain

Abstract

The paper describes the problems and advantages of pain therapy in the equine species during and after a surgical intervention. It is stated that an additional pain therapy before and during inhalation anaesthesia reduces the risk of postoperative complications. Acute visceral pain (colic) provokes clearly visible symptoms and the effect of a pain therapy is not only visible but also gives further information about the diagnosis of an acute abdominal problem. The determination of chronic visceral pain in horses is difficult, and clear parameters of the degree of pain sensations are not existent. Somatic pain originating from the locomotor system must be expected when gait irregularities (lameness) are present. When both limbs are affected, the evaluation may be difficult. Under severe pain the horses show increased pulse and respiratory rates, sweating, lifting of the affected limb and decreased mobility (i.e. in acute laminitis). A lameness in horses is a symptom of pain and requires an adequate pain therapy, mainly when horses are used in all disciplines of equestrian sport. This treatment, however, is illegal (doping regulations). The determination of back pain in the horse is very difficult, mainly because the performance is generally not reduced. Different symptoms are known, but do not allow a clear judgement of existing pain. Unfortunately parameters for determination of pain symptoms in horse under the saddle or in the harness do not exist. The judgement requires a profound knowledge not only of the equine species, but also of the different breeds, characters and of the single animal. The performance of a horse is a very bad parameter for existing pain symptoms in the locomotor system. The equine surgeon has the duty to detect pain symptoms according to the movement and the behaviour of a horse; he also has the duty to inform the horse owner and the rider about the ethical problems, when a horse under pain has to perform.