SYMPTOMS, COURSE, AND COMPLICATIONS. 57 



animal may still be stiff, and liave difficulty in moving, but 

 restlessness and pain are less marked. 



A somewhat similar condition of the evacuations and more 

 important secretions exists here to what we find in other 

 modifications, where a preference of selection in the specific 

 action of the poison is shown in the direction of the respiratory 

 membrane proper. 



It has been noticed that in this type of catarrhal distemper 

 there is a more marked tendency to sudden and unexpected 

 death of the patient than in any other, and that this unex- 

 pected and fatal termination is to be attributed to the presence 

 of thrombi in the cavities of the heart. This disposition to 

 form thrombi has been attributed to the excess in the blood of 

 the fibrinogenous — fibrine -forming — materials, characteristic 

 of this type of the disease. Probably this condition, when it 

 does occur, may have an influence in the production of these 

 clots ; still we must not shut our eyes to the fact that another 

 and equally probable cause, and quite demonstrable, may also 

 exist, viz., the participation by the valvular structures and 

 appendages of the cardiac cavities in the specific action of the 

 invading virus. We know that anatomically these are com- 

 posed of tissue analogous to that which seems specially impli- 

 cated in this manifestation of the fever. Nor must Ave forget 

 that thrombi may form, in certain conditions of cardiac action, 

 rather rapidly. 



2. Of the Thoracic or Pulmonary Form. — As abeady stated, 

 the catarrhal form of the fever, in its varied manifestations, 

 may justly be regarded as the simplest ; and it has usually so 

 far expended its force that the affected animal is in fourteen 

 days fairly convalescent. 



Comphcations, evidencing involvement of the thoracic 

 viscera, may, however, at any stage retard the recovery : they 

 generally show themselves rather early than late ; they may, 

 indeed, be present from the commencement of the attack. 



These thoracic complications naturally arrange themselves 

 in several distinctive groups, chief of which are — a. Capillary 

 bronchitis ; h. Bronchitis,ivith cardiac disease ; c. Pneumonia, 

 or rather Pleuro-pneumonia. 



a. Capillary Bronchitis. — At any stage of the initiatory fever 

 chest symptoms may become distinctly marked : the respira- 



