Cause. Old layers are generally affected. The cause may be the strain of heavy laying, or may in cases be due to too much internal fat.
Treatment. No satisfactory treatment can be recommended and the bird had best be killed. Such birds should not be used for breeding purposes.
BRONCHITIS (CROUP)
Not very common
Symptoms. Bronchitis may be distinguished by the rattling in the throat of the bird affected and by the rapid breathing and cough. The rattling is due to mucus in the inflamed bronchial tubes. In bad cases, birds mope, refuse to eat, and soon die.
Cause. Bronchitis may develop from an ordinary cold, or may be due to sudden changes of temperature, or to exposure to rain, cold, and damp.
Treatment. Keep affected bird away from drafts and in a warm place; dose with Epsom salts (see page 9) and give soft food, e. g., bread, bran, and middlings, with milk. Wine of ipecacuanha has been recommended for cases in which breathing is very difficult owing to excessive inflammation.
BROODER PNEUMONIA
A very serious disease, causing the death of many chickens
Symptoms. Chickens affected stand by themselves with roughened plumage. There is a whitish diarrhea, and this disease can easily be mistaken for white diarrhea. (See page 92.) Post-mortem examination will show yellowish spots on the lungs, on the walls of the air sacs, and on the liver and other organs, due to infection by the aspergillus fungus. (See page 29.)
Cause. Infection by a species of the aspergillus fungus, the spores of which are probably inhaled. This fungus is common. The spores may be in the straw used for nests or for litter, or in the food, especially if it is at all moldy.
Treatment. There is no cure for an affected chicken, and the poultryman must aim at prevention. Vigorous sanitary measures are imperative. Clean straw or excelsior should be used for nests; eggs for hatching should be disinfected by wiping with 80% alcohol; incubators and brooders should be thoroughly disinfected.