Redwater in Cattle. 
143 
Redwater in Cattle. 
The disease known by the above name has at the present 
day a comparatively restricted distribution in England, being 
apparently almost unknown except in the extreme northern 
counties and in Devon and Cornwall. It is, on the other 
hand, a fairly common disease over the whole of Scotland 
and throughout the greater part of Ireland. With some 
exceptions which will be specially considered later, cases of 
redwater are seen only in the summer and autumn seasons, 
and only in cattle which are running at grass. It has always 
been observed that it is a rare disease on cultivated land, being 
more frequent on land which has never been brought under 
the plough, such as hill or moor pasture and meadows. On 
this account it has long received the name “ moor-ill ” in 
Scotland. It is specially a disease of adult cattle, though it 
may attack yearlings or two-year-olds, and occasionally even 
calves of not over six months old. The disease received its 
common name from the fact that affected animals pass 
dark-red urine, the abnormal colour being due not to actual 
blood mixed with the urine, but to the presence of haemoglobin 
or blood-pigment. 
Until quite recently the most erroneous views were 
generally put forward and accepted with regard to the cause 
of the disease, the commonest being that the malady was the 
result either of actual poisoning with some noxious herbs or 
weeds, or of a diet in some respect improper, such as one 
containing a great excess of carbohydrates. Within the last 
few years, however, the cause and true nature of the disease 
have been determined with certainty, and at the present time 
there are few diseases of cattle which are so well understood as 
redwater. The actual cause of the disease is a microscopic 
animal parasite, very similar to the one which is the cause 
of human malaria. During the height of the disease this 
parasite is found in larger or smaller numbers in the red 
corpuscles of the blood, and all the principal symptoms 
exhibited by an affected animal are ascribable to the 
destruction of the corpuscles which these parasites bring 
about. When the corpuscles are destroyed their red colouring 
matter becomes dissolved in the liquid paid of the blood, and 
when excreted by the kidneys it imparts the abnormal colour 
to the urine. In an ordinary fatal case of redwater the blood 
is obviously thin and watery, and the carcass is even more 
bloodless in appearance than that of an animal which has been 
killed by bleeding. 
Although redwater is not a contagious or infectious disease 
in the ordinary sense of these words, it is one which can be 
experimentally conveyed from a diseased to a healthy ox with 
