ANAPHYLACTOID PHENOMENA IN THE HORSE, CAUSED BY THE INJECTION OF COLLOIDAL SOLUTIONS

Abstract

Immediately after the injection of about 10c.c. of 0.1-1.0% Arabian rubber solution (in 0.9% NaCl solution) or 0.5% agar solution or 15% decoct. rad. altheae into the jugular vein of a horse, a striking phenomenon appears which lasts a short course of time, say, from a few minutes to 10 minutes or more. In most cases the horse survives, but there are sometimes fatal cases.From a clinical point of view, or from physico-chemical examinations of blood, no remarkable difference could be found among those phenomena caused by the injection of different kinds of solution. Especially the phenomena due to the first two kinds of solution resemble each other so much that we cannot distinguish one from another. They both bear a close resemblance to an anaphylactic shock. The following is the short description of the phenomena.Clinical symptoms.Immediately after the injection, the animal becomes restless and begins to move or sway its body. The exposed mucous membranes become extremely pale, accompanied by difficult respiration, rapid and irregular pulsation and accerelated peristalsis. False mastication, salivation and perspiration are also to be noticed. Excretion of feces is a constant symptom. Tremor of the whole body or of a certain group of muscles is noticed. Within a short course of time the animal manifests comatic symptoms: it can no longer bear to loading, lies down or falls down if the case is very severe. After lying down dyspnoea becomes more marked. The anaemia of the exposed mucous membranes is within a few minutes followed by remarkable hyperaemia.All the symptoms as described above subside in 10-30 minutes and the general condition of the animal becomes quite normal, but, as mentioned above, there are some exceptional cases which result in death.Changes in the blood.The principal changes in the blood taken from the horse injected are as follows:(1) Remarkable leucopenia lasting a short course of time, (2) Relative increase of the red blood corpuscles, (3) Increase of the solid substance esp. the sugar in blood plasma (hyperglycaemia), (4) Momentary increase of the CO2, content in blood plasma, followed by its decrease i. e. acidosis, (5) Temporary rise in blood pressure immediately followed by its fall etc.In order to determine those changes in the blood, I have employed the following methods; -Pulfrich's immertion refractometer method (reading the deviation of the refraction index of blood serum) for the determination of the solid substances in blood plasma, Bang's method (1920) for the measurement of sugar content in the total blood, Mayer and Bailey's method for the same in blood plasma, Van Slyke's method for the measurement of the CO2 content in blood plasma and Ludwig's method for the purpose of determining blood pressure, using a mercury manometer connected with arteria carotis communis of the horse by means of a rubber tube.The relation between the intensity of those phenomena and the concentration or dose of the colloidal solution is not clear yet, but it seems probable from the results obtained in 22 cases (Arabian rubber solution in 15 cases, agar solution in 6 cases, decoct. rad. altheae in 1 case) that the intensity of the phenomena has an intimate relationship to the individual disposition. In those 22 cases (21 horses) I have noticed, though there was only one animal which showed no reaction to the first injection, that the intensity of the symptom became gradually weaker according to the repetition of injection. In the horse narcotised by the administration of chlorat. hydrat. no or very slight reaction to the injection of each of those colloidal solutions was observed. The mode of injection seems to exert a great influence upon the intensity of the phenomena which may also be brought about by subcutaneous injection.