title: Rhodococcus equi pneumonia in foals: an assessment of the early diagnostic value of serum amyloid A and plasma fibrinogen concentrations in equine clinical practice.
abstract: Early diagnosis and prevention of Rhodococcus equi pneumonia in foals represent important goals for equine clinicians. Recent protocols for diagnosis and treatment of Rhodococcosis in foals typically rely on a multimodal approach based on sonographic evidence suggestive of pyogranulomas, sonographic abscess scores and laboratory findings including plasma fibrinogen concentrations, blood biochemistry testing and platelet and leukocyte counts. The aim of this study was to assess the utility of weekly testing of serum amyloid A (SAA) and plasma fibrinogen concentrations in foals to achieve early diagnosis of R. equi pneumonia prior to the onset of clinical signs. This testing was used to simulate a clinically practical screening procedure and compared with thoracic ultrasonography performed in parallel. The present study suggests that SAA does not represent a reliable early marker of Rhodococcosis when plasma concentrations are tested weekly. However, when clinical signs of R. equi pneumonia are present, SAA concentrations may allow clinicians to obtain 'real-time' indications concerning both the progress of infection and the effectiveness of therapy. This study 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 as suspected of R. equi infection. Future investigations regarding both physiological plasma fibrinogen concentrations in foals as well as fibrinogen kinetics in foals affected with R. equi pneumonia, including the establishment of appropriate reference intervals for the test method employed in this study, will be necessary in order to clarify this possibility.
authors.affiliation: Centro di Studio del Cavallo Sportivo, Department of Veterinary Medicine, University of Perugia, Via San Costanzo 4, Perugia PG 06126, Italy. Electronic address: fabrizio.passamonti@unipg.it.
authors.forename: F
authors.initials: F
authors.lastname: Passamonti
authors.affiliation: Centro di Studio del Cavallo Sportivo, Department of Veterinary Medicine, University of Perugia, Via San Costanzo 4, Perugia PG 06126, Italy.
authors.forename: D M
authors.initials: DM
authors.lastname: Vardi
authors.affiliation: Centro di Studio del Cavallo Sportivo, Department of Veterinary Medicine, University of Perugia, Via San Costanzo 4, Perugia PG 06126, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Stefanetti
authors.affiliation: Centro di Studio del Cavallo Sportivo, Department of Veterinary Medicine, University of Perugia, Via San Costanzo 4, Perugia PG 06126, Italy.
authors.forename: M L
authors.initials: ML
authors.lastname: Marenzoni
authors.affiliation: Centro di Studio del Cavallo Sportivo, Department of Veterinary Medicine, University of Perugia, Via San Costanzo 4, Perugia PG 06126, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Prato
authors.affiliation: Veterinary Clinic, 47 Bigozzi St., Monteriggioni SI 53035, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Cévese
authors.affiliation: Centro di Studio del Cavallo Sportivo, Department of Veterinary Medicine, University of Perugia, Via San Costanzo 4, Perugia PG 06126, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Coletti
authors.affiliation: Centro di Studio del Cavallo Sportivo, Department of Veterinary Medicine, University of Perugia, Via San Costanzo 4, Perugia PG 06126, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Pepe
authors.affiliation: Centro di Studio del Cavallo Sportivo, Department of Veterinary Medicine, University of Perugia, Via San Costanzo 4, Perugia PG 06126, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Casagrande Proietti
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Colorado State University, Fort Collins, CO 80523-1644, USA.
authors.forename: F
authors.initials: F
authors.lastname: Olea-Popelka
mesh_terms: D000193:Actinomycetales Infections / Q000097:blood / Q000382:microbiology / Q000662:veterinary*; D000818:Animals; D001774:Blood Chemical Analysis / Q000662:veterinary*; D005340:Fibrinogen / Q000378:metabolism*; D006734:Horse Diseases / Q000097:blood* / Q000382:microbiology; D006736:Horses; D016929:Rhodococcus equi / Q000502:physiology; D000685:Serum Amyloid A Protein / Q000378:metabolism*; D013997:Time Factors; D014463:Ultrasonography / Q000662:veterinary*
chemical_list: D000685:Serum Amyloid A Protein; D005340:Fibrinogen
keywords: Diagnosis; Fibrinogen; Foal; Rhodococcus equi; Serum amyloid A