436 DISEASES OF THE BLOOD. 



the disease was so long regarded as due to climatic influences. Even at 

 the present day, when it is known to be due to a specific organism, the 

 action of temperature, etc., must still be regarded as i^robably playing an 

 important part in infection. The disease is said not to occur in mild 

 weather ; but whether or not this be true, every one is agreed that it is 

 principally seen during frost, especially when frost is unaccompanied by 

 snow. 



From experience gained both in Iceland and Norway, the disease 

 appears to be often localised in certain districts and fields — a fact largely 

 accounted for when we learn that up to the present little or no attempt 

 has been made to prevent the spread of infection from the dead 

 bodies. 



Braxy chiefly attacks young animals, and is rare in those over three 

 years of age. Hjaltelin estimates the number of deaths in a single 

 district during the years 1849 — 1854 at approximately 6,000, made up 

 as follows : — 



Yearling lambs . . . . . . . . . . . . . . 2,440 



Two-year sheep . . . . . . . . . . . . . . 2,460 



Three-year sheep . . . . . . . . . . . . . . 1,020 



Annuals older than three years . . . . . . . . . . 80 



The younger animals suffer most, and in Norway Nielsen directs 

 attention to the heavy fatalities amongst lambs. 



Symptoms. The sheep suddenly appears ill, is dull, lies about, and 

 cannot be induced to rise ; all movement seems to give pain, and from 

 time to time the animal groans ; the posterior parts of the body become 

 swollen, and a little froth often escaj^es from the mouth. The pulse 

 varies between thirty and thirty-five per minute, and is often imperceptible 

 in the extremities ; the temperature may rise to 105° or even 108° Fahr. 

 This condition may last some hours, and always ends with the animal's 

 death; sheep, which overnight had shown no signs of illness, are often 

 found dead in the morning. The incubation period is from forty-eight to 

 sixty hours, but ordinary cases seldom live longer than from five to eight 

 hours after the symptoms declare themselves. 



The striking post-mortem appearances, especially the haemorrhagic 

 inflammation of the abomasum, were early the subject of remark. This 

 appearance is very characteristic. 



If the animals are slaughtered, the most important change is found to 

 be a purplish, dark, somewhat swollen patch in the abomasum; during 

 the course of the disease this increases in size, and if the animal should 

 be allowed to die of braxy the entire abomasum shows haemorrhagic or 

 sero-hsemorrhagic infiltration ; the abomasum and the first part of the 

 small intestine usually contain no food, but may often show a certain 

 amount of bloody fluid. This haemorrhagic inflammation may extend in 



