Association between radiographic pattern and outcome in foals with pneumonia caused by Rhodococcus equi.
Abstract: Our objective was to characterize the association between types of radiographic findings and outcome in foals with pneumonia caused by Rhodococcus equi. Admission lateral thoracic radiographs of 62 foals with culture-confirmed R. equi pneumonia were reviewed retrospectively. A scoring system was developed to individually assess the severity of alveolar pattern, interstitial pattern, tracheobronchial lymphadenopathy, pleural effusion, and the number of nodular opacities and cavitary lesions. Individual scores were added to obtain a total radiographic score ranging from 0 (normal) to 22. Forty-three of 62 foals (69%) survived to discharge. The median total radiographic score of nonsurvivors (14; range, 9-16) was significantly (P = 0.007) higher than that of survivors (11; range, 4-15). Foals with a total radiographic score of greater than or equal to 15 were 6.15 times (95% CI: 1.35 to 28.2) less likely to survive than foals with a lower score (P = 0.019). A multivariate logistic regression model was used to identify the potential associations between specific types of radiographic lesions and outcome. The model was statistically significant (P = 0.002) and correctly classified 75.8% of foals. Only severity of alveolar pattern and number of cavitary lesions made statistically significant contributions to the model. There was no significant association between concurrent isolation of other bacteria along with R. equi and the types or severity of radiographic lesions. Based on the results of this study, severity of alveolar pattern and number of cavitary lesions are the radiographic findings significantly associated with a poor outcome in foals with R. equi pneumonia.
© 2012 Veterinary Radiology & Ultrasound.
Publication Date: 2012-06-29 PubMed ID: 22742474DOI: 10.1111/j.1740-8261.2012.01964.xGoogle Scholar: Lookup
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- Journal Article
Summary
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The research tries to relate the types of radiographic findings with the outcomes of foals (young horses) suffering from pneumonia caused by the ‘Rhodococcus equi’ bacteria. The results suggest that severity of alveolar pattern and the number of cavitary lesions as indicated by radiographs can predict the chances of survival from this lung infection.
Methodology and Findings
- The study analyzed the lateral thoracic radiographs of 62 foals admitted for treatment of R.equi pneumonia. The radiographs were reviewed retrospectively to identify various patterns and abnormalities in the lungs.
- A scoring system was initiated to evaluate the severity of observable characteristics such as alveolar pattern, interstitial pattern, tracheobronchial lymphadenopathy, pleural effusion, number of nodular opacities, and cavitary lesions. The sum of these individual scores resulted in a total radiographic score ranging from 0 (normal) to 22 (high abnormality).
- Out of the total 62 foals, 43 (69%) survived the disease. It was observed that the median total radiographic score for those who did not survive (14; range, 9-16) was significantly higher than that of the survivors (11; range, 4-15).
- The results showed that foals with a total radiographic score of 15 or more were 6.15 times (95% CI: 1.35 to 28.2) less likely to survive than those with a lower score.
Statistical Analysis
- A statistical method, known as multivariate logistic regression model, was used to uncover potential relationships between specific types of radiographic lesions and the survival outcome.
- The model proved to be statistically significant, correctly classifying the outcome of 75.8% of foals.
- However, only the severity of the alveolar pattern and the number of cavitary lesions significantly contributed to the prediction made by the model.
Additional findings and Conclusion
- The study found no significant relation between the concurrent presence of other bacteria along with R. equi and the types or severity of the observed radiographic lesions.
- Therefore, this research concludes that among all the radiographic findings, the severity of the alveolar pattern and the number of cavitary lesions have the most significant association with poor survival outcomes in foals suffering from R. equi pneumonia.
Cite This Article
APA
Giguère S, Roberts GD.
(2012).
Association between radiographic pattern and outcome in foals with pneumonia caused by Rhodococcus equi.
Vet Radiol Ultrasound, 53(6), 601-604.
https://doi.org/10.1111/j.1740-8261.2012.01964.x Publication
Researcher Affiliations
- Department of Large Animal Medicine, University of Georgia, Athens, GA, USA. gigueres@uga.edu
MeSH Terms
- Actinomycetales Infections / diagnostic imaging
- Actinomycetales Infections / mortality
- Actinomycetales Infections / veterinary
- Animals
- Horse Diseases / diagnostic imaging
- Horse Diseases / mortality
- Horses
- Lung / diagnostic imaging
- Pneumonia, Bacterial / diagnostic imaging
- Pneumonia, Bacterial / mortality
- Pneumonia, Bacterial / veterinary
- Radiography, Thoracic / veterinary
- Rhodococcus equi
- Sentinel Surveillance
- Survival Rate
Citations
This article has been cited 8 times.- Rakowska A, Marciniak-Karcz A, Bereznowski A, Cywińska A, Żychska M, Witkowski L. Less Typical Courses of Rhodococcus equi Infections in Foals. Vet Sci 2022 Oct 31;9(11).
- Hepworth-Warren KL, Nelson N, Dembek KA, Young KAS. Comparison of thoracic ultrasonography and thoracic radiography between healthy adult horses and horses with bacterial pneumonia using a novel, objective ultrasonographic scoring system. Front Vet Sci 2022;9:991634.
- Rakowska A, Cywinska A, Witkowski L. Current Trends in Understanding and Managing Equine Rhodococcosis. Animals (Basel) 2020 Oct 18;10(10).
- Aslam MW, Lau SF, Chin CSL, Ahmad NI, Rahman NA, Kuppusamy K, Omar S, Radzi R. Clinicopathological and radiographic features in 40 cats diagnosed with pulmonary and cutaneous Rhodococcus equi infection (2012-2018). J Feline Med Surg 2020 Aug;22(8):774-790.
- Giguère S, Berghaus LJ, Miller CD. Clinical Assessment of a Point-of-Care Serum Amyloid A Assay in Foals with Bronchopneumonia. J Vet Intern Med 2016 Jul;30(4):1338-43.
- Fenton CS, Buckley TC. Minimum inhibitory concentrations of erythromycin and rifampin for Rhodococcus equi during the years 2007-2014. Ir Vet J 2015;68:23.
- Yerlikaya Z, Karagülle B, Otlu B, Muz A. From Paddock to Foal: Prevalence and Genotypic Diversity of Rhodococcus equi on Stud Farms in Türkiye. Vet Sci 2026 Jan 10;13(1).
- Villalba-Orero M, Gómez CA, Valero-Gónzalez M, Venegas N, Criado G, Martín-Cuervo M. Blood parameters in neonatal foal and colostrum quality as possible early markers for increased risk of developing Rhodococcus equi pneumonia. Front Vet Sci 2025;12:1654052.
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