Prognosis. 189 



Prognosis. Tlie prognosis of the catarrhal form of in- 

 fluenza is usually favorable, as deaths sekloni occur except as 

 a result of complications, the appearance of which are com- 

 monly associated with unfavoral)le hygienic conditions. Under 

 favorable conditions the loss hardly ever exceeds 0.5 to 1% ; it 

 may however reach 4% and even more. Accordingly in the prog- 

 nosis all existing circumstances, as well as the benign or the 

 malignant character of the disease should be taken into con- 

 sideration. 



The prognosis of the pectoral form of influenza is much 

 more unfavorable. In this form the losses are never less than 

 4 to 5%, and frequently considerably higher (according to 

 Dieckerhoff the average is 16%). Besides it should be also 

 considered that in addition to the losses resulting from death 

 some of the animals do not completely recover, and that their 

 protracted convalescence may greatly diminish the value of the 

 animals through the lessening of their ability to work. 



The life of the affected animal is imperiled in the first 

 place by danger of paralysis of the heart. Indications of a 

 weak heart always render the prognosis unfavorable, and in 

 the presence of a soft empty pulse of over 80 beats, as well 

 as when a venous pulse can be detected, the chances of recovery 

 are very slight. 



The termination of the disease depends also on the extent 

 of the pneumonia and pleurisy. A unilateral pneumonia with 

 only slight pleuritis usually terminates favorably; on the other 

 hand a bilateral affection, and especially the formation of 

 great quantity of pleural exudate is always grave. In such 

 cases, even at the best, the course of the disease is very pro- 

 longed, and chronic changes of the respiratory organs usually 

 remain as a sequel to the disease. 



Moderate fever, and at least a fair appetite, are favorable 

 prognostic signs. The more regularly the different stages of 

 the disease follow each other, the more favorable is the prog- 

 nosis, while a rapid change for the worse in the respiration, 

 with very high fever, without a distinctly demonstrable dullness 

 (pneumonia centralis!), usually results in death after a few 

 days. The dangers from cases of a hemorrhagic character 

 are in most instances great (bloody nasal discharge, similar 

 pleural exudate!). 



According to Frohner, prognostic conclusions can be made in every case of 

 contagious pleuro-pneumonia, from the consistence of the exudate which may be 

 obtained by aspiration. If the exudate contains no bacteria the prognosis is always 

 favorable; on the other hand, in the presence of bacteria (streptococci) the disease 

 as a rule has a fatal termination. 



The course of the fever is of great importance in the prog- 

 nosis, especially in the pectoral form of influenza. If the tem- 

 perature, after rising rapidly, remains for several days ap- 

 proximately at the same height, and if it falls towards the 

 end of the first week just as rapidly, or even gradually, the 

 prospect of a favorable termination is excellent. If, on the 



