CHAPTER XXXIX, 



POULTRY DISEASES AND VICES. VERMIN. 



FOR several reasons, to treat minutely of every 

 disease known to occur in poultry would be 

 of little use to the practical poultry keeper, 

 especially as most competent veterinary practi- 

 tioners nowdevote real studyto this branchof their 

 profession, and are able to render aid in serious 

 cases. There are several useful special treatises 

 accessible to the few who are really competent to 

 make use of them* ; but many causes of death 

 which can be easily determined by ^post-mortem 

 examination present no symptoms during life to 

 mark them off from others, especially to the 

 ordinary observer, even though familiar with his 

 birds. The skin of a fowl does not perspire 

 (practically, at least, as there are no sweat- 

 glands), and very little liquid is excreted by the 

 kidneys ; and the skin being covered over with 

 feathers also, it will be seen how whole classes of 

 symptoms must be wanting, which in other 

 animals we can examine and form our opinion 

 upon. Many ailments from which fowls have 

 died, arc also very rare ; and upon the whole little 

 can be done to assist the majority, except in 

 regard to complaints ordinarily met with, and 

 whose symptom? are fairly constant and defined. 

 That so large a proportion of these relate to 

 the respiratory system, arises from the peculiar 

 anatomy of birds. The moisture other animals 

 excrete through the skin and kidneys, is in them 

 almost entirely given off in breathing. In birds, 

 also, the ordinary lungs and air-passages are 

 supplemented by nhie air-sacs, communicating 

 with those organs, and supplying them with a 

 certain quantity of air in the intervals of breathing. 

 This extra oxygenation is connected with the 

 higher temperature of the body, which exceeds 

 fever-heat in other animals. At all events, these 

 air-sacs expose larger surfaces to possible dis- 

 turbances, including certain microscopical para- 

 sites, and the wider functions of the whole 

 apparatus give more prominence to its work in 

 the system, and increase its liability to disease 



• For such British readers, The Diseases of Poultry, by J. 

 Woodroffe Hill, F.R.C.V.S., "Feathered World" Office, 

 London, may be useful. The best American work is The 

 Diseases of Poultry, by D. E. Salmon, D.V.M., George 

 Howard and Co., Washington, D.C. French readers possess 

 Midecine des Oiseaux, by Pierre Megnin ; German poultry- 

 keepers have at command Die Krankhtiten des HausgeftUge/s, 

 by Friedrich A. Zuern. 



76 



There is another point of view, of great im- 

 portance. In a large proportion of cases of 

 disease, the birds ought to die or be killed. Even 

 where there is no constitutional taint, the fact 

 that they have succumbed to circumstances which 

 have not affected others, marks them out as the 

 weakest, which unaided Nature would assuredly 

 weed out, and which if we preserve and breed 

 from, perpetuate some amount of that weakness 

 in the progeny. Rheumatism, for instance, can 

 be cured ; of that there is no doubt. But the 

 vast majority who have had such success, agree 

 that the effects are either never recovered from 

 as regards strength and vigour, or else that the 

 original weakness continues ; and the same may 

 be said of some severe contagious diseases, 

 such as diphtheritic roup, which may affect the 

 strongest On the other hand, many diseases also 

 apparently contagious, and so attacking healthy 

 birds under certain predisposing conditions of 

 exposure or other coincident strain upon the 

 system, do not appear to leave serious results 

 behind them, and are tolerably definite in 

 symptoms and character. It is these which may 

 be most successfully treated, and in which treat- 

 ment is most worth while where fowls of value are 

 concerned. But it is significant that nearly all 

 breeders who rear really large numbers of poultry, 

 gradually come to the conclusion that, except in 

 special cases, with valuable birds, the most 

 economical treatment of serious disease occur- 

 ring in a yard is — execution. Concerning this 

 matter each must judge for himself. 



Before proceeding with details, three other 

 general points require mention, (i) The first is 

 the absolute necessity for a hospital, adequate to 

 the establishment, where sick birds can be both 

 placed in comfort and under observation, and 

 kept from infecting others, at all events after dis- 

 covery. (2) The second is a question of dosage. 

 Fowls are not homoeopaths, and take relatively 

 large doses, so that if any reader wants to try 

 any new remedy, suggested perhaps by his own 

 doctor, a large fowl may have about one-third of 

 the dose for a human adult. Further, however, 

 where the doses are given as two for the day, it 

 would often be far better if the same quantity 

 could be subdivided and given in three or four 

 portions instead. For colds in particular, we 



