MINERAL OR INORGANIC POISONS 39 



Diagnosis. — The sudden appearance of violent symptoms 

 of colic, thirst, straining, and purgation in large animals, 

 or of vomiting in dogs, will arouse suspicion that irritant 

 poisoning, probably by arsenic, has occurred. 



Symptoms. — Numerous recorded cases have fairly estab- 

 lished the general symptomatology of arsenic. There are 

 to be distinguished the local irritant and remote nervous 

 effects. The arsenic compounds do not precipitate albumin, 

 and the irritant effect has thus a different mechanism from 

 that due to heavy metal salts. In general, in acute poison- 

 ing of the herbivorsB one has to note — salivation, thirst, 

 loss of appetite, vomitibn when possible, violent colic, foetid 

 diarrhoea of alliaceous odour, and sometimes bloody, ex- 

 haustion, collapse, and death. Apart from the extreme 

 debility, there may be noted paralysis of the hind extremi- 

 ties, coldness of ears and horns, and a subnormal tempera- 

 ture, with trembling, stupor, and convulsions. The onset of 

 symptoms and death may be extremely rapid, so that the 

 animal may never be noticed to be ill. In more prolonged 

 cases giddiness, muscular tremors, colic, and coldness will 

 be prominent. The urine is albuminous and often bloody. 



The notes by Bevan^ give an excellent summary of 

 arsenical poisoning. The effects due to absorption through 

 the skin, noted by that observer — viz., a scalded appear- 

 ance and sloughing in patches, especially round the eyes, 

 over the scrotum of the bull, or udder and vulva of the cow 

 — recall the parallel effects of arsenical eruption in man. 



In dogs a large dose (3 to 10 grains) causes nausea, 

 vomiting, moaning, hard and rapid pulse, painful evacua- 

 tions, and death in convulsions in from six to thirty hours. 



Chronic poisoning is less frequent and less well marked 

 with animals than with man ; few cases are to be found in 

 the veterinary literature. As characteristic of it, there are 

 noted diminution of sensibility, difficulty in movement, and 

 eventually entire abolition of the motor and nutritive func- 

 tions. Indigestion, thirst, great wasting, and chronic disease 

 of the joints have been observed amongst animals living 

 near smelting works in Cornwall and Wales. 



