DISEASES OF THE OX AND SHEEP. 675 



Septicaemia, or blood-poisoning, is due to the existence in the 

 blood of germs which are called the micrococci of septicaemia. As 

 yet but little is known respecting these small vegetable growths, 

 and as to the different kinds of them which occur in different kinds 

 of animals; but that they grow and multiply in the blood, and 

 «hoke up the blood-vessels, so that the nutrient fluid contained 

 in them cannot perform its normal functions, has been clearly 

 established. 



In the process of giving birth to young, the surfaces are 

 generally more or less lacerated, and in the weak state of the 

 animal at the time, the process of healing and repair is not as 

 rapid as it would be in an animal under ordinary circumstances. 

 The germs, therefore, are quick to propagate themselves in the 

 suitable nidus presented by the wounded and bleeding surfaces, 

 which are naturally more or less exposed to the air after the 

 expulsion of the young. Once having gained an entry into 

 the blood, they have no great difiBculty in growing and 

 lultiplying, and hence they soon swarm in the blood-vessels of 

 the body, and from them are propagated to all parts. The 

 impoverished cells of the blood and tissues cannot battle with 

 -them, as perhaps the active healthy cells of a normal animal 

 might be able to do. 



No doubt the disease is largely communicated either by the 

 , medium of the air, or by that of contact with infected ewes, or by 

 le unsuspecting shepherd. He, all unconscious of what he is 

 [oing, conveys the disease from ewe to ewe, and, while tending 

 the animals, supplies the dread cause of death by his hands and 

 clothes. Doubtless this is a not unusual method of propagation, 

 'he diseased animal itself may also spread the contagion, and, 

 therefore, in all cases those ewes which are attacked should be at 

 mce isolated, and removed to some distance from the rest of the 

 lock. It is possible, too, that the germs may, when once they 

 lave entered into the system of the ewe, take on more virulent 

 )roperties and more active powers — that the germs, in other 

 rords, may become more accustomed to living in the blood- 

 vessels, and also be more readily conveyed by the medium of the 

 -air. If this is so, it is evidently the first step which tells, and 

 hence the greater care should be taken to stamp out the disease, 

 fcefore it has had time to extend itself. 



This " parturient septicaemia " is so fatal in its character that, 



43 " 



