194 CLINICAL VETERINARY MEDICINE AND SURGERY. 



sometimes followed by laminitis affecting the front, the hind, or all 

 four feet. Certain myopathic paralyses, phlebitis, and purpura are also 

 possible accidents. Finally, the disease may be complicated with 

 ophthalmia or deafness. 



Secondary inflammations of articular and tendinous synovial mem- 

 brane may appear early or late in the disease. Sometimes they are 

 deferred for several weeks or even months after the resolution period. 

 The commonest are those of the sheaths of the great sesamoid, and of 

 the carpus or tarsus. Their development was long considered due to 

 retention in the body of injurious products resulting from reabsorption 

 of pulmonary exudates, but like other complications of pneumonia they 

 are produced by infectious organisms or their toxins. 



The anatomical changes in contagious pneumonia are seldom 

 limited to the lung and pleura, but extend to the intestine, liver, kidneys, 

 heart, and sometimes to the serous membrane, nerve centres, or to 

 other organs. 



The lungs are almost always gravely affected, — sometimes, however, 

 only over a very limited area. In the patient which died from brain 

 complication you saw that the hepatised portion of lung was hardly as 

 large as two fingers, and occupied the anterior part of the right lobe. 

 Friedberger and Frohner believe that the organism which usually 

 produces pneumonia may affect a patient without in any way damaging 

 the lung, but this is certainly very exceptional. 



In general both lobes are partially invaded. Hepatisation usually 

 occurs in the antero-inferior portion, extending upwards to a varying 

 and unequal height in either lung. Not infrequently the middle 

 (vertical) section of the lobe shows the greatest change, hepatisation 

 extending higher there than in the anterior or posterior parts ; some- 

 times the lesion is limited to the neighbourhood of the large bronchi, 

 the superficial layers escaping. The hepatised parts are distinguished 

 from the rest of the lobe by their deep blackish coloration, and by 

 their much greater density and firmness, even when the healthy parts 

 of the organ are more or less hypersemic. Sometimes they form a 

 single uniform mass, sometimes they show prominences and depressions 

 somewhat resembling the condition seen in canine distemper. The 

 bronchial glands are always enlarged and infiltrated to some extent. 



The appearance of sections through hepatised parts depends on the 

 duration of the condition, and on whether the pneumonia is lobular or 

 lobar. 



In recent cases of lobar pneumonia the areas of hepatisation are 

 blackish in colour, rounded or irregular in outline, and separated by 



