548 



THE BOOK OF POULTRY. 



answers upon really wide and good range. It 

 will be seen that circumstances and appropriate 

 management may differ in many details which 

 it is impossible to specify, but which intelli- 

 gence will grasp and turn to account. 



A disease among turkeys that has ravaged 

 whole flocks in Rhode Island (America) and 

 adjoining districts, and which has occurred 

 with disastrous results in Australia, 

 "Blackhead" is that known as Blackhead. So 

 in Turkeys, far, fortunately, the complaint has 

 not troubled English rearers ; but 

 since importations of American stock are some- 

 times made into Great Britain, the importer of 

 American turkeys should as a precautionary 

 measure quarantine his newly-arrived birds. 

 The name blackhead was given to the disease 

 (scientifically known as Infectious Entro- 

 hepatitis), which originated in America, owing 

 to the fact that at a certain stage the affected 

 turkey's head turns quite black. About the 

 year 1894 the disease spread with such alarm- 

 ing rapidity, and decimated so many large 

 flocks, that Dr. Theobald Smith was requested 

 by the United States Department of Agricul- 

 ture to make investigations concerning it ; and 

 he subsequently reported that it was caused by 

 protozoa, a low form of microscopic life. He 

 likened the disease to amebic dysentery in the 

 human subject, and stated that it is charac- 

 terised by large sores in the ceca and liver. 



Treating of the disease in a bulletin issued 

 by the Rhode Island Experiment Station, Mr. 

 Cooper Curtice says : " The majority of young 

 poults die after a day or two of droopiness. 

 Adults may droop longer, and pass into 

 chronic stages of the disease. Refusal to eat 

 and standing apart constitute late symptoms. 

 When the disease in the cecum is slight, it is 

 doubtful if the affected birds have diarrhoea, 

 which is more or less present in other cases. 

 In many of the older poults the droppings 

 will be liquid and stained orange-yellow ; this 

 is the most characteristic symptom of all. . . . 

 When yards are infected, two weeks will suffice 

 for the ameba to kill very young poults, three 

 weeks suffice for killing older ones, and 

 scarcely a longer period is required for adults. 

 . . . One point of interest to turkey-raisers 

 is that the experiments show that four-fifths of 

 the young poults exposed to infected yards 

 die before they are six weeks old. . . . The 

 amebEe are transmitted from diseased turkeys 

 to others through the droppings, which con- 

 taminate the food with which they come in 

 contact. Evidence obtained here indicates that 

 the amebas may also be carried by ordinary 

 fowl, and may be transmitted by them to 



turkeys in the same manner. . . . The evi- 

 dence at hand indicates that turkeys may con- 

 tract blackhead disease at any time of life. 

 While the disease is usually fatal upon the 

 first infection, both poults and adults may 

 contract it, recover, and finally die during 

 another attack in a subsequent year. These 

 facts seem to indicate that immunity is not 

 acquired by previous disease nor by age. . . . 

 The fact that the common hen rarely succumbs 

 to the disease, but occasionally has it, demon- 

 strates that she would be an admirable natural 

 host for the parasite. Every fact so far 

 learned adds a link to the circumstantial evi- 

 dence that may convict her as a carrier of the 

 disease organism. If this be the case, hens 

 and turkeys should neither live together nor 

 be near neighbours. ... In despair the 

 poultryman asks if there is not something he 

 can give to cure the turkeys. There is as j^et 

 no known efficacious remedy, and there is 

 probably no medicinal remedy discoverable 

 which can be economically administered. . . . 

 Although nostrums are wanted, and will be 

 demanded by the breeder, his way to success 

 will be in the eradication and prevention of the 

 disease rather than in employing specific pre- 

 parations from which only the holder of the 

 formula and the dealers are likely to profit. 

 . . . Since the blackhead disease seems to 

 have been prevented in large part by dryness 

 of the surroundings, it is apparent that sandy, 

 well-drained lands afford better advantages 

 for raising turkeys than the heavier, moist clay 

 lands, and hence the former situations should 

 be chosen. The turkey attendant should not 

 attend the ordinary fowls unless he under- 

 stands the danger of carrying infection to the 

 turkeys, and provides against it. Above all, 

 the turkeys should be kept away from the hen 

 yards and farmhouse at all times, or, if this 

 is impracticable, the ordinary fowl should be 

 kept within fenced enclosures to which the 

 turkeys can never gain access, and care should 

 be taken not to have the turkeys near the 

 boundaries of such enclosures by feeding them 

 at such points." 



On farms where blackhead has existed, the 

 following measures are recommended to be 

 adopted by Mr. G. Bradshaw, in a Farmers' 

 Bulletin, issued by the New South Wales 

 Department of Agriculture : — The liberal use 

 of slaked lime in the yards previously occupied 

 by the diseased turkeys. The following is a 

 serviceable disinfectant: Crude carbolic acid, 

 half a gallon; crude sulphuric acid, half a 

 gallon. These two substances should be mixed 

 in tubs or glass vessels. The sulphuric acid 



