72 
Parasites of Cattle and Sheep. 
considerable attention, and it is now believed that in the 
production of the disease known in the United Kingdom as 
“ Red water,” ticks play an important part. From time 
immemorial, in various parts of the kingdom, particularly 
in Devon, Cornwall, the northern counties, Scotland, and 
Ireland, both adult and young cattle have been liable to an 
affection, more or less fatal, whose most striking symptom 
is the passage of blood-coloured urine, and commonly 
known as “ Redwater.” There seems little room for 
doubt that the appearance of this disease depends on ticks. In 
this affection, the tick probably plays the role of carrier of a 
disease germ, a low form of life, called a piroplasm , which it 
introduces into the blood of its host. This germ dissolves 
out from the red blood corpuscle its colouring matter, which 
appears in the urine. These piroplasms are obtained by 
sucking the blood of cattle containing them, but one of the 
most remarkable features is the transmission of the piroplasm 
to the progeny of the tick. 
If a mature female tick is taken from an animal suffering 
from redwater, and its young are hatched apart from affected 
animals, and placed on healthy animals, these become affected 
with redwater. If some of the blood of such animals is injected 
into a healthy animal, the latter takes the disease. It has been 
observed that after an animal has had redwater and apparently 
recovered, the disease may recur if the animal is subjected 
to any debilitating conditions. Animals bred and reared in 
situations where redwater is common appear less liable to 
take the disease in a serious form, while purchased animals 
often suffer very severely. The disease rarely affects cattle 
grazing on high ground, or that which has been recently 
cultivated. Though this affection is not a disease of the skin, 
it is as substantially due to the attack of skin parasites as the 
irritation which results from their movements and punctures. 
In Great Britain the number of ticks attacking an animal is 
usually small, and the symptoms of local irritation are not 
very severe. 
Treatment . — The knowledge of these facts suggests increased 
attention to the maintenance of the skin free from parasites. 
Experiments with sheep dips have shown that any of those 
effectual in scab will rid animals of this pest ; this is applicable 
to ticks on cattle. For prevention, cattle should be kept off 
infested pastures and places where there is old, dry grass or 
undergrowth. The burning of dry grass, &c., and the plough- 
ing of infested fields are indicated, while the sure method of 
dealing with ticks on cattle is to pick them off and burn them ; 
the application of a little paraffin facilitates this somewhat 
tedious process. 
