Apparently chemical reaction between copper sulphate and zinc phosphide 

 under certain conditions affected the durability of the compound. Further 

 study disclosed' that there v/as little probability of bringing about effect- 

 ive emesis in dogs » There was little likelihood also that dogs Y;ould be 

 accidentally poisoned by picking up one or t\-;o of the siaall baits as 

 properly exposed for the control of field mice. These facts led to de- 

 creased interest in the emetic-poison study in orchard mouse control. 



RECBJIT 770RK 



In 1942 study ivas resumod to improve methods for the control of rats 

 as part of a r/crtime proioct. The principal goal of this vj-ork vjas to 

 afford protection to dogs and cats, the most frequent victims of accidental 

 poisoning from rat bait. The investigations v/ere designed to appraise the 

 emetic properties on dogs'' and- cats of antimony oxide, copper sulphate, zinc 

 sulphate, and tartar emetic (antimony-potassium tartrate; in combination 

 vxith the poisons zinc phosphide, thallium sulphate, and barium carbonate, 

 and to learn the acceptability to rats of bait in v^hich those chemicals 

 were incorporated. 



In these investigations 91 dogs and 41 cats were used, Alexandrine 

 rats (Rattus rattus alexandrinus ) vrore selected for the bait-acceptance 

 trials. Tests involving the use of the poisons were based on the follo^ring 

 minimum lethal dose ratings: zinc phosphide, 40 mg./kg. (milligrams per 

 kilogram); thalliijm sulphate, 35 mg./kg,; and barium carbonate, 700 mg./kg. 



Antimony Oxide 



Antimony oxide was tested on the basis of reports tho.t it caused 

 emesis in dogs when used in combination with zinc phosphide, but it did 

 not so affect t'.vo out of three experimental animals. These dogs were 

 given 75, 75, and 98 mg,/kg,, respectively, of zinc phosphide and an equal 

 quantity of antimony oxide. The first and third of the animals, in which 

 emesis did not occur, died rdthin 24 hours; the second vomited within 78 

 minutes and survived. Zinc phosphide alone induced emesis in a dog fed 

 50 mg,/kg, of the poison, and this animal survived, Tv:o dogs given 100 mg/icg, 

 doses of the poison died in about 12 hours mthout having vomited. 



Copper Sulphate 



Copper sulphate, although found to be relatively effective in in- 

 ducing emesis in dogs, was not sufficiently acceptable to Alexandrine 

 rats to warrant its use in bait. 



Zinc Sulphate 



Zinc sulphate in doses up to 15 rag, /kg. did not produce enesis in 

 dogs and cats. 



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