SAEVA Congress 2018 Proceedings | 12-15 February 2018 | ATKV Goudini Spa
Initial treatment duration can be estimated from the initial ultrasonographic findings and their severity . A horse with anechoic pleural effusion and compression atelectasis , a small (< 5 cm ) abscess , or small (< 5 cm ) area of parenchymal consolidation , may only need 2 - 4 weeks of appropriate antimicrobial therapy before antimicrobials can be discontinued , if subsequent clinical and ultrasonographic findings indicate a response to therapy . Slightly larger areas of consolidation ( 5 - 10 cm ) may resolve with 1 - 2 months of appropriate antimicrobial therapy . Severe consolidation usually results in treatment durations of 2 - 6 months , or longer , depending upon the severity of the pneumonia . Abscesses usually also require treatment durations of 2 - 6 months or longer , depending upon their size , number , and degree of encapsulation . Treatment duration for horses with complex , septated pleuropneumonia , anaerobic pleuropneumonia , and necrotizing pneumonia is also long , usually 2 - 6 months or longer . These initial guidelines can be used to formulate a therapeutic plan for treatment duration that will be subsequently modified by the clinical and ultrasonographic response of the horse to therapy .
Follow-up ultrasonographic examinations should be based upon the severity of the underlying pulmonary and pleural disease and the horse ' s clinical signs . If significant quantities of pleural effusion are detected , an ultrasonographically guided thoracocentesis should be performed to obtain a sample for cytological examination , culture , and sensitivity testing . Repeat ultrasonographic examinations should be performed every several days ( or daily , if indicated ) if thoracic auscultation and percussion indicate fluid accumulation . Once pleural fluid ceases to accumulate ( or in horses without pleuritis ) the frequency of repeat ultrasonographic examinations can be based upon the severity of the parenchymal disease and its response to therapy ( every 3 - 10 days initially unless pneumonia very severe ). Ideally , antimicrobials should be continued until the consolidation or abscess has resolved ultrasonographically and is replaced by aerated lung . When this is not practical , the decision to discontinue therapy is made based on the response of the horse to therapy . The horse should be re-examined ultrasonographically 1 - 2 weeks after discontinuing antimicrobials to assure continued improvement in the ultrasonographic appearance of the lung and pleural cavity . The horse should be periodically re-examined ( every 4 - 8 weeks ) until the lung and pleural cavity return to normal before returning the horse to training . Occasionally , small adhesions or areas of pulmonary nonaeration and scarring persist in horses that have recovered from pleuropneumonia but this is the exception , rather than the rule . If horses are put back into training before the lung or pleural cavity have returned to normal , periodic ultrasonographic re-examinations are indicated to be certain that the pulmonary or pleural disease is not worsening with the stress of training .
Most horses with solitary pulmonary abscesses have returned successfully to racing . The majority of Thoroughbred horses with pleuropneumonia were able to race at least once following successful treatment of pleuropneumonia . The prognosis for racing is worse for those that developed a cranial thoracic mass or a bronchial pleural fistula . The long term survival of foals with pulmonary abscesses was 56 % in one study .
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