132 DISEASES OF 



sometimes takes place in great numbers in a short time 

 without the death of the whole animal: we know that in 

 this disease the coloring matter of the blood ( haematin ) 

 which is mostly contained in the red corpuscles is 

 filtered through the walls of the blood vessels in large 

 quantities, thus showing that there is a disintegration 

 or breaking up of the formed elements of the blood itself. 

 We may therefore consider it purely as a blood disease. 



Causes. It usually, though not always, follows some 

 debilitating disease, as distemper and pneumonia. Bad 

 ventilation is often an auxiliary cause, as are also errors 

 in feeding, and very hard work, especially if long con- 

 tinued, where the vital energies are very much weak- 

 ened. 



Symptoms. Sudden appearance of swellings on va- 

 rious parts of the body ; the head and limbs rarely 

 escape. There is always some rise of temperature, but 

 usually not to a very high point ; the breathing and 

 pulse are nearly always quickened ; the animal will 

 show stiffness in the limbs, depending on the extent of 

 the swellings in them. The appetite is sometimes very 

 bad, at other times fairly good. Bed spots the size of 

 a copper cent or larger are frequently seen on the inside 

 of the nostrils. It should be borne in mind that the 

 same kind of swellings that occur on the surface of the 

 body may occur internally, in which case the complica- 

 tions may be of a very serious nature. For instance, if 

 the lungs are invaded, pneumonia ensues ; if the intes- 

 tines are affected over any large surface, we may have 

 active purgation. The development of internal swel- 

 lings is where the great danger lies in this disease. 



treatment. First of all, good ventilation, and plenty 

 of clothing on the surface of the body. For the first 



