Moore. — Study of Trout Diseases. 85 



The first signs are most apparent internally in an extensive inflamma- 

 tion of the intestine and peritoneum. Sometimes the symptoms of 

 enteritis are lacking and the second, or ulceration stage, manifests it- 

 self directly. As described in typical furunculosis, hemorrhagic spots 

 appear in the deep or shallow portions of the muscle. These spots 

 quickly develop into sores which eventually break through the overlying 

 flesh. The skin gradually bulges out, producing "furuncles" or swellings 

 varying from the size of a pea to the size of a nut. The inside of the 

 sore contains a purulent mass of muscle fibres, pus and bacteria. On 

 perforation of the sores flat ulcers appear; some of them deep and not 

 larger than a five cent piece. A foul colored, bloody mucous flows from 

 them, but generally this is washed away by the movements of the fish in 

 the water and the spots appear less bloody. The later German author- 

 ities indicate that the ulcer or sore is a manifestation which may or may 

 not be present in furunculosis. 



The course of the disease is usually short, death occurring in two to 

 three weeks after infection. In the earlier writings the authorities in- 

 dicated that the disease is most likely to occur where there is putrefac- 

 tion in the bottom of the pond and in the water, especially when in the 

 course of artificial feeding remains of food in excess foul the bottom. 

 But later, as observations were extended to wild waters, it was found 

 that pollution did not enter into the question. It was found that in wild 

 waters infection does not follow so suddenly, nor so severely as under 

 artificial conditions and the disease may last longer, including a period 

 of several weeks or several months. It was found that a bacterium 

 (B. salmonicida) was the inciting cause of the disease and produced a 

 very general infection, spreading throughout the body, in the blood, 

 liver, kidneys and muscles. 



Certain manifestations of the ''ulcer disease," as described by 

 Calkins and Marsh during epidemics at Cold Spring, L. I., show a 

 striking similarity to furunculosis. The diflFerence between the two 

 diseases lies apparently in the origin of the ulcer. According to the 

 German authorities furunculosis is caused by a bacterium ; according to 

 Marsh the ulcer disease is not but belongs to the type "whose living 

 causative agents are not to be cultivated outside the body by the usual 

 methods." The ulcer, as described by Marsh, is of the rodent type. It 

 starts as a spot on the skin and erodes on all sides, progressing just be- 

 neath the skin, leaving overhanging edges or flaps of loose skin. In 

 furunculosis the ulcer penetrates the flesh. The ulcers described by 

 Calkins may be shallow or deep, and it seems quite probable that the 

 disease we have in this country is a manifestation of furunculosis. 



Mr. Adams: Do you believe that furunculosis can be transmitted 

 through the egg, as is probable with the disease you have been discuss- 

 ing this morning? 



Dr. Moore: It is possible that the disease is transmitted through 

 the egg. We know little as yet of e^g infection, but by analogy with 



