SIMPLE ACUTE BRONCHITIS. Simple acute bronchitis co-exists with, or is often only the logical and inevitable complication of, coryza and acute laryngitis. It is commonly associated with inflammation of the mucous membrane of the trachea. It accompanies cold and wet seasons, and usually appears with the autumn frosts, in animals still at grass. In animals under shelter it occurs after undue exertion followed by chills, and after sudden rain storms. It also attacks working oxen, which are much exposed to the weather. =The symptoms= follow very rapidly on the determining cause. They are ushered in by rigors, trembling attacks, diminution or loss of appetite, arrest of rumination, acceleration of breathing, and the appearance of a rough and spasmodic cough. In ordinary cases these symptoms rapidly diminish, even without treatment. The appetite again becomes moderate, rumination returns, but the cough remains more or less rough and spasmodic, ending in the discharge, or more often in the swallowing, of abundant bronchial mucus. This is the condition at the period of crisis. Percussion of the thorax reveals normal resonance. On auscultation of the sides during the period of onset, rough _râles_ are heard, which at the period of crisis are replaced by mucous _râles_. The cough diminishes in frequency, and after a fortnight everything again becomes normal. =The diagnosis= is very easy, the important point being not to confuse common bronchitis with tuberculous bronchitis, which very often assumes a chronic form. =Prognosis.= The prognosis is not grave, even though the disease may assume a chronic condition. =Treatment= does not differ from that of acute bronchitis in the horse. It consists in antiseptic and steam fumigations, tepid drinks, the administration of doses of 2 to 3 drachms Kerme’s mineral in adult animals, and of 1 to 1½ drachms of iodide of potassium, given in a mash or in honey electuary. During convalescence tar water should be administered. CHRONIC BRONCHITIS. Chronic inflammation of the mucous membrane of the large bronchi and trachea may follow acute bronchitis, but it is also a frequent termination of verminous bronchitis. It is found in fully developed animals, adult or old, and particularly in those inhabiting wet, cold valleys. It is characterised by frequent paroxysms of coughing, which appear on the slightest provocation, such as the action of cold air on leaving the stable or of the air of a confined space on animals returning from the open; concussion of the chest by the pleximeter, squeezing of the loins, rapid movement, etc. This coughing is accompanied by the discharge of mucus, which rarely arrives at the nostrils, but is swallowed in passing through the pharynx. Such mucus is always thick, greenish yellow in colour, and without smell.