PREVENTIVE MEDICINE 331 



DIABETES INSIPIDUS. POLYURIA. 



The terms " diabetes insipidus " and " polyuria " are employed 

 by some observers (Hutyra and Marek) as designations for some- 

 what different conditions, the symptoms of " polyuria " being 

 similar to those of " diabetes insipidus," but are quite transitory 

 in nature. By others the terms are used synonymously. 



Diabetes insipidus of the horse, due to feeding on fodder, grains 

 or hays that are in a state of fermentation, is a disease which has 

 received relatively little attention from the scientific investigator, 

 and, so far as the author knows, no serious attempt has been made 

 to discover its real cause. Such hay or grain which is musty or 

 mowburnt, i.e., which has fermented, produces a greatly increased 

 secretion of urine, of pale colour and lower specific gravity than 

 normal, but free from albumen and sugar. There is great thirst 

 and emaciation is rapid, and if the damaged food is given persist- 

 ently the animal becomes weak and languid. 



A similar train of symptoms is sometimes present in the course 

 of certain chronic contagious disorders, e.g., glanders and tuber- 

 culosis. In the case of diabetes insipidus, due to fermented fodder, 

 the symptoms ameliorate when the harmful food is omitted from 

 the ration, but no benefit ensues until this is done. Musty oats are 

 more deleterious than mowburnt hay; indeed, the latter may be 

 given with safety if it is introduced into the dietary cautiously. 



Speculation as to the actual causative agent is idle; it may be 

 found in the products of carbohydrate fermentation or, what is 

 probably more likely, among the amino-acids resulting from dis- 

 integration of protein. 



DISEASES AFFECTING POULTRY. 



The diseases of poultry which demand notice are the follow- 

 ing : fowl cholera, avian diphtheria, epithelioma contagiosum, 

 fowl plague and fowl typhoid. 



The three diseases first mentioned are seen in Great Britain, 

 while the remaining two (fowl plague and fowl typhoid) have not 

 been described in these islands up to the present. 



FOWL CHOLERA. Fowl cholera is caused by an organism of 

 the pasteurella type. The disease is very acute and infectious, and 

 outbreaks occasionally occur not only in the fowl but also amongst 

 other birds of the farmyard, including pigeons. The virulence of 

 the organism in nature varies considerably and some strains appear 



