_Training_ or _breaking_ is another reason for the predisposition in the young. The first experience of the _hot, impure, infected air_ of the stable, the unwonted _grain feeding_, the _excitements_ and _perspirations_ attendant on the first handling all contribute to temporary loss of resistance. _Fatigue_ like other weakening conditions lays the system open to attack. _Chill_ is a most efficient cause, hence the disease often prevails most extensively in spring and autumn, at the time of changing the coat, and of passing from stable to field and the converse. Joly relates that in Russia where large numbers die of strangles through imperfect stabling in winter, immunity is sought through a milder first attack, brought on in the milder autumn weather by turning the young animals into a deep pool for half an hour and then exposing them freely to cold winds and giving cold water to drink. The omnipresent germ takes occasion to attack the cold debilitated system. Any _change of latitude_ or of locality acts in the same way. Riquet even alleges that this will bring about a second and even a third attack. It is common, he says, for newly bought young horses to have the disease at Hamburg, and after recovery to have a second attack at Hanover and finally a third one after they join the regiments in France. A similar exhaustion of immunity has been repeatedly noticed in the case of canine distemper. _Horse trading_ and the _stabling of large numbers_ together is naturally the most fruitful of infection and hence strangles is a virtual plague in dealers’ studs. The buildings in such cases are reinfected at short intervals with virulent types of the streptococcus, and fresh susceptible animals are being constantly introduced to keep it up. Riquet says that in Northern Germany dealers avoid this largely by traveling their purchases in bands of 100 or 150 head, from ten to twelve miles a day, feeding sparingly, and turning them like sheep into an open park at night regardless of the weather. Much of the advantage is doubtless from the avoidance of stable infection and the warm relaxing air of indoors. _A sea voyage_ especially favors infection and a single victim placed on board will speedily contaminate all susceptible animals present. Finally the predisposing influence of _catarrh of the air-passages_ must not be overlooked. The inflamed mucosa furnishes a most inviting infection entrance.