i-:FFECTS OF SXAK1-: V1:NC)MS on DOMKSTIC ANl.MALS. ^5 1 



symptoms usually result in tree deffecation which is not accom- 

 panied h\- diarrhoea, and the suhsecjuent recovery is rapid. 

 Mamba venom produces an acute and violent colic accompanied 

 by increased peristalsis and frequent discharg^e of fsecal matter; 

 later the discharge becomes fluid, and frequently death results. 



For treatment of an animal during reaction, inhalations of 

 ammonia seem to have a good effect. })articularly in the case of 

 the reaction following injection of puff-adder venom. The onset 

 of the symptoms of colic can be to a great extent ])revented by 

 the administration of a bran mash on the evening preceding the 

 injection. 



The (juantity of venom required to hyperimmunise a horse 

 varies considerably, but in no case has the quantity exceeded 

 2 grammes. It would appear that the more severe the reaction 

 produced, even in cases where the increase was com]jaratively 

 small, the more rapid did the serum develoj) antivenomous pro- 

 ])erties. Owing to the variations in toxicity of venoms obtained 

 from dift'erent sources, it will be found advisable to procure suffi- 

 cient venom to complete the hyj^erimmunisation before commenc- 

 ing inoculations. These various venoms should be mixed toge- 

 ther so as to obtain a mixture of constant toxicity, and thus one 

 will be enabled to control the reactions resulting from an in- 

 creased dose, and the increase can be regulated with more accu- 

 racy. The initial injection of venom should be regarded as a 

 test of the animal's -powers of resistance to the venom employed, 

 and should in no case exceed one-quarter of the minimal lethal 

 dose. As a result of a number of ex])eriments, it has been 

 ascertained that inoculations at lo-day intervals produce the 

 most satisfactory results, and give rise to less risk of dangerous 

 anaphylactic reactions. The rate of increase of the venom de- 

 pends uj^on the susceptibility of the animal, and one has to be 

 guided by the severity and duration of the resulting reactions. 

 With cobra and adder venoms an initial dose of 5 mgm. can be 

 given in most cases with safety. The increase at first must be 

 slow, but will depend on the reaction developed^ and after a few- 

 injections the animal will tolerate an increase of 5 to 8 mgm. at 

 each injection. In the case of mamba, the initial injection must 

 not exceed 2 mgm. and subsequent increases must be carried out 

 carefully. In most cases it wall be found that an animal will 

 stand an increase of 2 mgm. at each injection, after some immu- 

 nity has been developed ; but it must be remembered that, as in 

 the cobra and puft'-adder, no definite lines can be laid down, and 

 the reaction must serve as a guide. 



The time necessary to produce a serum which will be suffi- 

 ciently active depends to a great extent on the animal, as immu- 

 nity, and as a result more active serum, develops more ((uickly in 

 some horses than in others. In the case of animals being hyper- 

 immunised against cobra and adder, the serum v/ill be found to be 

 sufliciently active when the animals stand an intravenous injec- 

 tion of 75-100 mgm. of described venom. It is the practice to 

 test the animal's serum when no reaction occurs after an injec- 



