Cruzel in addition mentions a double respiratory movement like that produced in the horse by broken wind. This is really the result of hydro-thorax, and is not a constant symptom.
D. General symptoms. When the disease has lasted a certain time the patients show certain well-marked general symptoms: they remain standing in one position for long periods, with the head and neck extended, the front legs thrust outwards from the trunk and the body rigid, as though the least movement caused them pain. The general attitude expresses anxiety, the animals lie down with great care and seldom remain long in this position, which interferes with the functions of the heart and lung. In the last stages the animals remain constantly standing, appetite is almost entirely lost, and they waste rapidly.
The course of pericarditis due to foreign bodies is very variable. Sometimes death occurs in eight or ten days. In other cases the animal may survive for weeks, provided it is well tended. Everything depends on the rapidity with which the foreign body moves and on the character of the infectious organisms which it introduces into the pericardium. Death is the inevitable termination, and occurs as a consequence of cardiac and respiratory syncope. It may follow suddenly as the result of a simple forced movement, even when the animal still seems to retain some amount of strength. When the organisms introduced into the pericardium are of marked virulence, complications such as septic pleurisy and pneumonia may be observed, and death soon takes place.
It has been suggested that recovery might follow a return of the foreign body towards the reticulum. This view can only have been advanced as a consequence of errors in diagnosis, either as to the existence of pericarditis or as to its nature. Pericarditis due to cold or rheumatism sometimes becomes cured spontaneously.
Death, again, may suddenly occur by syncope when the foreign body penetrates the myocardium, passes through it, and enters the ventricular cavities.
The return of the foreign body is not conceivable, at all events after it arrives in the pericardial cavity. Up to that time the only disturbance is of a digestive character; no pericarditis exists. But when for example the disturbance is due to long fragments of iron wire which may extend from the reticulum as far as the pericardium, it is clear that the pericarditis is of a kind which cannot be cured without leaving traces. In our opinion, natural recovery is impossible.
Diagnosis. The diagnosis of pericarditis cannot be made until such pericarditis actually exists, i.e., until the disease has arrived at the third stage of development mentioned above.
As long as the symptoms point only to the first or second stage, the logical diagnosis is reticulitis produced by a foreign body. At this time the development of pericarditis, although possible, is not inevitable.
When, on the other hand, one knows how the digestive disturbance has originated and developed and thereafter notes signs of cardiac irritation, disappearance of the cardiac impulse, dulness of the heart sounds, venous stasis, etc., the diagnosis is easy even thus early.
Mistakes are not very likely. Only in some cases are they liable to occur, as in acute peripneumonia of the anterior pulmonary lobes, causing compression of the pericardium of the anterior vena cava and producing secondarily venous stasis and œdema of the dewlap. Cases of specific pericarditis due to peripneumonia also occur, and under such circumstances a mistake would be even more excusable. Nevertheless, the temperature curve in itself is a sure indication, for whilst in peripneumonia the fever is always very marked, it is scarcely noticeable in pericarditis due to a foreign body.