Rhodococcus equi pneumonia in foals: an assessment of the early diagnostic value of serum amyloid A and plasma fibrinogen concentrations in equine clinical practice.

The research paper is about a study that evaluates the usefulness of weekly testing of serum amyloid A (SAA) and plasma fibrinogen concentrations in foals for early diagnosis of Rhodococcus equi pneumonia before clinical signs appear.

About Rhodococcus equi pneumonia

• Rhodococcus equi pneumonia is a severe lung disease that affects young foals. If not diagnosed and treated early, it can cause serious health complications and even death.
• Traditionally, the diagnosis of Rhodococcosis in foals is based on a combination of sonographic evidence suggestive of pyogranulomas, sonographic abscess scores and laboratory findings including plasma fibrinogen concentrations, blood biochemistry testing, and platelet and leukocyte counts.

Objective of the study

• The goal of this research was to find out if weekly testing of serum amyloid A (SAA) and plasma fibrinogen concentrations in foals could help in early diagnosis of R. equi pneumonia prior to the onset of clinical signs.
• The weekly testing of these elements was conducted alongside thoracic ultrasonography for comparison.

Findings from the study

• The findings reveal that serum amyloid A (SAA) does not provide a reliable early marker for Rhodococcosis when plasma concentrations are tested weekly.
• However, when clinical signs of R. equi pneumonia are present, SAA concentrations can give ‘real-time’ indications about the progression of the infection and the effectiveness of therapy.
• The study also raises the possibility that plasma fibrinogen monitoring, starting at 1 week of age and repeated on a weekly basis, could serve as a screening test allowing clinicians to identify foals suspected of R. equi infection.

Future investigations

• The research concludes by suggesting that further exploration on the physiology of plasma fibrinogen concentrations in foals is required.
• It recommends studying fibrinogen kinetics in foals affected with R. equi pneumonia, and establishing appropriate reference intervals for the test method used in the study, to better understand its potential effectiveness as a screening test.