_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. BUMBLEFOOT _Not serious if treated early_ [Illustration: FIG. 9.—BUMBLEFOOT] _Symptoms._ Lameness with swelling on pad of foot. _Cause._ Injury to sole of foot, developing into an abscess. Heavy birds are more subject than light ones to bumblefoot, especially if made to roost on perches that are too high. _Treatment._ Paint with iodine. Lance the abscess if it is sufficiently advanced. Lower perches. Birds under treatment should have their feet bandaged, and should be put on deep straw to prevent further injury while the wounds are healing. Not serious if taken in hand promptly. CATARRH OF THE CROP _Not a common trouble_ _Symptoms._ Distention of crop with soft pasty matter of a more or less offensive character. _Cause._ Eating stale, putrifying food or some poisonous matter. _Treatment._ Empty the bird’s crop by holding the head downwards and gently pressing the contents out through the mouth. Feed sparingly on soft food. CHICKEN POX OR SORE HEAD _An infectious disease that causes considerable loss among chickens and young birds in warm climates_ _Symptoms._ Small, scabby, wart-like growths and eruptions on the head, especially on the comb and the wattles and around the eyes—in bad cases extending to the lids and even the mouth. Chickens and young birds are most commonly attacked by this disease, which spreads rapidly. [Illustration: FIG. 10.—CHICKEN POX] _Cause._ The specific organism has not been definitely determined. Chicken pox may be started by the introduction of an infected bird, and mosquitoes and other insects are suspected of being agents in its spread.