48 HEALTH AND DISEASE 



Irritant poisons are not all corrosive, in the sense of quickly destroying 

 and perforating the tissues. Ammonia is an example of an intense irritant, 

 and corrosive sublimate the most immediately destructive of living tissues. 

 The mineral acids show some difference in their local action. A yellow 

 staining results from nitric acid, sulphuric acid whitens the membranes, and 

 hydrochloric acid imparts a whity-brown appearance to the injured parts. 

 Carbolic acid, we have said, leaves a tell-tale odour, but it and the caustic 

 alkalies also make a white, drawn, or puckered surface of the membrane 

 with which they come in contact. Patches thus injured become presently 

 detached, or slough, leaving a raw surface and the expectoration of blood- 

 stained mucus. In dogs and other animals the vomit indicates to some 

 extent the amount of mischief in the stomach, but with the horse vomition 

 is uncertain and accomplished with so much difficulty that we are unable 

 to place any great reliance upon the appearance of ingesta ejected via the 

 nostrils, and probably stained in the effort to get rid of it. 



If death does not follow irritant poisoning in a few hours, the animal 

 may pass into a condition of fever with variable results. If the toxic agent 

 was of the corrosive class the patient may die of perforated stomach or 

 intestine when a general improvement in his condition has raised false 

 hopes of recovery in those interested. Gradual recovery is probable when 

 a week has passed, in the case of merely irritant poison, but not in those of 

 a corrosive nature. 



Permanent constrictions in the oesophagus, stomach, or bowels may 

 result from the healing scars where large areas of tissue are destroyed. 



ARSENIC 



This drug is employed in agricultural operations of various kinds, and 

 is a frequent cause of poisoning in horses and other animals. Ignorant 

 carters and grooms persist in using it to destroy worms and produce a 

 glossy coat, with little regard to its dangerous properties. Teamsters often 

 give it with antimony, and without causing any mischief at the time. 

 Arsenic, however, is one of the cumulative poisons, and ill consequences 

 may follow long after its habitual use has been discontinued. 



Cases of wilful poisoning by the drug are found recorded in veterinary 

 literature, but many occur also from the careless employment of sheep- 

 dipping compounds and " weed -killers ", which in various ways gain 

 entrance to the food and drink of animals. 



These preparations, composed of arsenic, with caustic alkalies to facili- 

 tate their solution, have a saline taste attractive to horses, and particularly 

 to cattle, which will lick an open packet of arsenical powder with evident 



