252 CLINICAL VETERINARY MEDICINE AND SURGERY. 



appears have been recognised. One cause — the action of which is 

 certain — has been indicated by almost all authors, viz. cold. It is 

 scarcely astonishing, then, that cases of hsemoglobinuria should be 

 particularly frequent during the winter, towards the end of autumn, 

 and in spring. Nevertheless it may also be seen at other seasons pro- 

 vided the temperature suddenly falls, or if other causes intervene. 



In general the disease is favoured by a plethoric state of body and 

 by rest. It may certainly affect animals in thin or moderate condition 

 which work every day, not even resting on Sundays ; but this is rare. 

 It more particularly attacks fat animals kept in ill-ventilated stables, 

 and which have rested for one or more days while receiving their 

 ordinary working rations. Should an animal thus prepared be taken 

 out or worked during cold weather, hsemoglobinuria may suddenly 

 appear. Indeed, it is not even necessary that the animal should be 

 taken out or directly exposed to cold ; sudden lowering of temperature 

 in the stable resulting in a chill is sufficient. Some years ago we had 

 a horse affected in this way in stable No. 5. It first showed symptoms 

 of colic, and the real nature of the disease was not recognised until a 

 little later, when dark-coloured urine was passed. Horses of all breeds, 

 classes, and ages are subject to hsemoglobinuria, though it seems par- 

 ticularly to affect heavy animals of plethoric temperament, which con- 

 sume large quantities of oats, and animals during the most vigorous 

 years of life. 



This explains both the appearance of the larger number of cases of 

 hsemoglobinuria during the morning hours when cold is most felt, and 

 the enzootic character which the disease sometimes appears to assume 

 at times when frost or snow prevent working ; large numbers of animals 

 which have been subjected to the same predisposing influences being 

 attacked almost simultaneously, or during the course of a few days. 

 Hsemoglobinuria has even been regarded as an infectious disease, and 

 the animals affected with it thought to have undergone some change of 

 tissue or blood-plasma, tending to prepare the way for the supposed 

 pathogenic agent. Experiments made with the object of verifying this 

 idea have not carried it beyond the stage of an hypothesis. Following 

 many others, I vainly attempted to transmit the disease to horses by 

 injecting under the skin and into the veins and peritoneum defi- 

 brinated blood and preparations from the affected organs. The 

 disease is not contagious, and cannot pass from affected to healthy 

 animals. In the rare cases where contagion or external infection 

 have been suspected, the patients which had been simultaneously or 

 successively affected had also been under the same conditions of feed- 

 ing, treatment, and work. 



