56 DISEASES OF CATTLE. 



but when brought in contact with dialyzed iron it forms an insohible 

 compound and becomes innocuous. Idiosyncrasies are not so notice- 

 able in cattle practice as in practice among human beings, but the' 

 uncertainty with which some drugs exert their influence would lead 

 us to believe that well-marked differences in susceptibility exist. 

 Even in some cases a tolerance for poison is engendered, so that in a 

 herd of animals equally exposed injurious or fatal effects do not 

 appear with unifornrity. For example, among cattle that are com- 

 pelled to drink water holding in solution a salt of lead the effects of 

 the poisoning will be found varying all the way from fatality to 

 imperceptibility. 



GENERAL, SYMPTOMS OF POISONING. 



It is not always easy to differentiate between poisoning and some 

 disease. Indeed, examination during the life of the animal is some- 

 times wholly inadequate to the formation of an opinion as to whether 

 the case is one of poisoning or, if it is, as to what the poison may be. 

 A chemical and physical examination after the death of the animal 

 may be necessary to clear up the doubt. On the other hand, the 

 symptoms may be of such a nature as to point unmistakably to poi- 

 soning with a certain agent. In general, the following classes of 

 symptoms may be regarded as indicative of poisoning: Sudden onset 

 of the disease without visible cause, a number of animals similarly 

 affected at once, severe gastro-intestinal disorder or derangement of 

 the nervous system, or both. Sudden alteration of heart action in 

 relation to fi'equency, force, or rhythm. Local irritation, dyspnea, 

 or change in the urine or urination. 



After death lesions of the greatest variety may be found, and it is 

 necessary for one to be skilled in anatomy and pathology to determine 

 their significance. Oftentimes the stomach and intestines are red, 

 have thick walls, and contain blood. This signifies a severe irritant, 

 such as arsenic or corrosive sublimate. Other alterations sometimes 

 found are inflammation of the kidneys or bladder, points of hemor- 

 rhage in various organs, changes in the blood, congestion of the lungs, 

 and certain microscopic changes. 



GENERAL TREATMENT. 



The treatment of animals suffering from poison must vary accord- 

 ing to the nature of the toxic agent. There are a few general plans 

 of action, however, which should be followed so far as possible. In 

 man and in some of the smaller animals it is possible to eliminate 

 unabsorbed poison by the use of the stomach pump or by causing 

 vomiting. These proceedings are impracticable in cattle. It is 

 well, therefore, in many cases to endeavor to expel the unabsorbed 



