=Diagnosis.= The diagnosis is usually easy. The history and the observed symptoms are often very clear, and the suddenness with which the obstruction has made its appearance prevent the condition from being confused with dilatation or stricture. =The prognosis= is very variable. It is often easy to remove the obstacle; in other cases intervention is difficult, and death may occur rapidly. =Treatment= is confined to one essential point—removal of the obstruction. The chief difficulty lies in choosing the mode of intervention. Moreover, success depends on several factors, which, in the order of their importance, are as follows: the size of the obstructing body; the time which has elapsed since the accident occurred; the bodily condition of the animal—_i.e._, whether it be fat or thin—and the extent to which tympanites has developed. The first thing to do (and in favourable cases all that is required) is to puncture the rumen and leave the canula for some time in position. The onward progress of the foreign body, especially when the obstruction is in the intra-thoracic portion of the tube, is often impeded by the tympanites, which tends to thrust the object towards the pharynx, or at least to fix it in position. In consequence of a sudden change in the conditions of pressure the foreign body may move and pass into the rumen; all danger is then at an end. Even though the obstruction does not immediately cease, puncture of the rumen, by removing the danger of asphyxia, allows one at least to wait for several hours, sometimes until next day, during which time the object may pass into the rumen without further extraneous assistance. The other methods may be grouped into four series: I. =External taxis.= This is directed towards loosening the foreign body and thrusting it towards the pharynx and buccal cavity. It can only be used against obstructions in the cervical region. Two methods, although very ancient, are still practised. (_a_) The first is carried out in the following way: the animal is fixed to a post or tree so that it cannot struggle, its head being drawn up as high as possible. The operator stands on the left side, with his back turned towards the patient’s head, his left hand is pressed into the right jugular furrow, his right hand is placed on the left jugular furrow immediately below the foreign body. By using the fingers the foreign body is moved, and is progressively thrust towards the pharynx, in spite of the animal’s efforts to swallow. In carrying out this manipulation it is absolutely indispensable not to let slip the obstructing body for a single instant, otherwise the peristaltic action will immediately return it to its former place. When it has been raised as far as the pharynx, an assistant passes his hand into the back of the mouth, as indicated in a former chapter, seizes the object and withdraws it; or, instead, the assistant takes over the operator’s duties, while the latter himself extracts the foreign body.