576 ANAPHYLAXIS 



sensitized animal, as little as 0.25 c.c. per kilo killing young, normal cats, 

 and 0.1 c.c. per kilo causing a fall in blood-pressure both in the normal 

 and in the sensitized animals. 



Dogs. In these animals the most constant symptom of anaphy- 

 laxis is an initial and transitory rise in blood-pressure, followed by a 

 prompt fall of from 80 to 100 mm. of mercury. This was first described 

 by Biedl and Kraus, 1 and subsequently by Eisenbrey and Pearce, 2 

 Robinson and Auer. 3 The general symptoms are not so violent as are 

 those that occur in the guinea-pig and death is infrequent. Following 

 intravenous injection of the intoxicating dose of serum there may be 

 great restlessness, marked prostration, and vomiting, tenesmus, and in- 

 voluntary discharge of feces and urine. If death does not occur, a con- 

 dition of hemorrhagic inflammation in both the large and the small 

 intestine may develop, called by Richet " chronic anaphylaxis, " and by 

 Schittenhelm and Weichardt, "enteritis anaphylactica. " Robinson 

 and Auer, by an electrocardiographic study, detected cardiac changes 

 consisting of disturbance of the heart impulses, abnormalities in ventric- 

 ular contractions, and other interferences with the mechanism of the 

 heart, due probably to the effect of horse serum on the peripheral car- 

 diac tissue, and independent of the drop in blood-pressure or any effect 

 upon the central nervous system. The heart changes do not appear to 

 exert a primary influence on the blood-pressure, which is due to an 

 effect upon the splanchnics, and is probably a secondary factor in ana- 

 phylaxis or vascular shock of the dog. In many instances there is 

 leukopenia, with loss of mononuclear cells. Coagulation of the blood is 

 delayed, a condition first described by Biedl and Kraus, 4 who believed 

 it to be due, probably, to a decrease in thromboplastin or an excess of 

 antithrombin. Pepper and Krumbharr 5 have shown that, by adding 

 small amounts of thromboplastin to the non-coagulating, post-anaphy- 

 lactic, oxalated plasma, the coagulability of the blood will be restored. 



As stated elsewhere, it may be difficult to produce anaphylaxis in 

 a dog. Usually a subcutaneous injection of 10 c.c. of horse serum, 

 followed in from three to six weeks by 5 c.c. intravenously, will at least 

 cause a marked fall in blood-pressure or fatal anaphylaxis. 



Other Animals. White mice and rats, while they may not develop 

 acute anaphylactic asphyxia, such as is observed in guinea-pigs, do react 



1 Wien. klin. Wochenschr., 1909, xxii, 365. 



2 Jour. Pharmacol. and Exper. Therap., 1912, iv, 27. 



3 Jour. Exper. Med., 1913, xviii, 556. 



4 Wien. klin. Wochenschr., 1909, ii, 363. 5 Jour. Infect. Dis., 1914, xiv, 476. 



