Adrenalectomy of the Calf and Its Effects on Various Blood Constituents

Abstract

Summary Surgical adrenalectomy was successfully performed in calves without suturing the wall of the vena cava, by using a special forceps to facilitate removal of the gland. Maintenance of adrenalectomized calves was possible under controlled conditions, with the intramuscular injection of 25mg. cortisone acetate or 5mg. prednisone plus 5mg. desoxycorticosterone acetate per 100lb. body weight, daily or every other day. Calves were also maintained in an apparently normal state without steroid therapy by the free-choice feeding of salt, which was consumed at a rate about four times that of the normal calf. The outward symptoms of adrenal deficiency, manifested during the period when no therapy was given, began with lethargy and weakness in the legs. This was followed by anorexia, extreme apathy, a completely prostrate position, and extreme depression and arrhythmia of the heart beat shortly before death ensued. Loose, foul-smelling feces and a rapid, labored respiration were sometimes observed. The calves survived about six to seven days following withdrawal of maintenance therapy. In three adrenal-deficient calves there was a decrease in the serum Na:K ratio, a decrease in serum chlorides, and an increase in serum potassium, all of which were highly significant (P less than 0.01). In two of the three animals there was a reduction in serum sodium, total neutrophils, and mature neutrophils, and an increase in RBC and eosinophils. The influence of adrenalectomy on serum calcium, blood hemoglobin, hematocrit, and neutrophil levels varied considerably between calves. No significant differences were found in WBC, lymphocyte, and monocyte levels following adrenalectomy. One calf was found to have an adrenal remnant which prevented it from succumbing completely to the effects of adrenalectomy.