270 BUREAU OF ANIMAL INDUSTRY. 



has once suffered from recurrent ophthalmia, and the French Govern- 

 ment studs not only reject all unsound stallions, but refuse service to 

 an}' mare v/hich has suffered with her eyes. It is this avoidance of the 

 hereditary predisposition more than an^'thing else that lias reduced 

 the f ormerl}' wide prevalence of this disease in the European countries 

 gcncrall3^ A consideration for the future of our horses would demand 

 the disuse of all sires that arc unlicensed, and the refusal of a license 

 to an}^ sire which has suffered from this cr any other communicable 

 constitutional disease. 



Other contributing causes deserve passing mention. Unwholesome 

 food and a faulty method of feeding undoubtedly i^rcdisposcs to the 

 disease, and in the same district the carefully fed will escape in far 

 larger proportion than the badl}^ fed. But it is so with every other 

 condition which -undermines the general health. The presence of 

 worms in the intestines, overwork, and debilitating diseases and causes 

 of every kind weaken the vitality and lay the system more open to 

 attack. Thierry long ago showed that the improvement of close, low, 

 dark, damp stables, where the disease had previously prevailed, prac- 

 tically banished this affection. Whatever contributes to strength and 

 vigor is protective; Avhatever contributes to weakness and poor health 

 is provocative of the disease in the predisposed subject. 



Symptoms. — The symptoms vary according to the severity of tlie 

 attack. In some cases there is marked fever, and in some slighter 

 cases this may be almost altogether wanting, but there is always a 

 lack of vigor and energy, bespeaking general disorder. The local 

 sjMnptoms are in the main those of internal ophthalmia, with, in many 

 cases, an increased hardness of the eyeball from effusion into its 

 cavity. The contracted pupil does not expand much in darkness, nor 

 even under the action of belladonna. Opacity advances from the 

 margin, over a part or whole of the cornea, but so long as it is trans- 

 parent there may be seen the turbid, aqueous humor with or without 

 flocculi, the dingy iris robbed of its clear black aspect, the slightly 

 clouded lens and a greenish yellow reflection from the depth of the 

 eye. From the fifth to the seventh day the flocculi precipitate in the 

 lower part of the chamber, exposing more clearly the iris and lens, 

 and absorption commences, so that the eye maj'^ be cleared up in ten or 

 fifteen da^'s. 



The characteristic of the disease is, however, its recurrence again 

 and again in the same eye until blindness results. The attaclrs may 

 follow each other at intervals of a month, more or less, but they show 

 no relation to any particular phase of the moon as might be inferred 

 from the familiar name, but arc determined rather by the weather, 

 the health, the food, or b}^ some periodicity of the system. From five 

 to seven attacks usually result in blindness, and then the second e3'e is 

 liable to be attacked until it also is ruined. 



