Clinical and Prognostic Significance of Radiographic Pattern, Distribution, and Severity of Thoracic Radiographic Changes in Neonatal Foals

Abstract

A total of 207 thoracic radiographs obtained from 128 foals were evaluated to assess the impact of pulmonary radiographic pattern, distribution, and severity of pulmonary changes on short-term survival of neonatal foals. The association between selected clinical variables and the radiographic manifestation of neonatal respiratory disease was also investigated. The evaluation of interstitial and alveolar-interstitial radiographic patterns within the caudodorsal, caudoventral, and cranioventral lung regions proved to be highly reliable between viewers in the study. A diagnosis of systemic inflammatory response syndrome was related to increased pulmonary infiltrates within the caudodorsal lung region. Dyspneic foals had more extensive pulmonary infiltrates within the cranioventral lung, advanced respiratory disease, and lower survival rates. A fibrinogen concentration >400 mg/dL was associated with increased cranioventral radiographic abnormalities. In addition, tachypnea most consistently related to diffuse (caudodorsal, caudoventral, and cranioventral) pulmonary changes. Neutropenia, milk reflux from the nares, upper airway pathology, abnormal respiratory sounds, failure of transfer of passive immunity (IgG concentration <400 mg/dL), immaturity, or fever, however, were not related to radiographic pattern, distribution, or severity of radiographic changes. Sixty-five percent of foals with radiographic pulmonary disease were discharged alive from our referral hospital. Concurrent caudodorsal and caudoventral radiographic disease was most frequently observed in this foal population. Increased caudodorsal radiographic scores retained statistical significance as a prognostic indicator for nonsurvival in a multiple stepwise logistic regression analysis.

Pneumonia Caused byKlebsiellaspp. in 46 Horses

“…pneumonia was 70%. Previous studies report survival of horses with bacterial pneumonia as low as 46% with more current studies reporting survival in up to 90% of cases . In our study, survival to discharge in horses <1 year of age was 79% (15/19), whereas overall survival to discharge in adults was 63% (17/27).…”

“…Previous studies in foals found that a diagnosis of SIRS was associated with pulmonary infiltrates within the caudodorsal lung. 17 Interestingly, the most common distribution of radiographic lesions in adults and foals in this study was in the caudodorsal lung field. This finding may indicate that SIRS resulted in vascular and pulmonary damage in the caudodosal lung fields, which have increased perfusion when compared to the remainder of the lung.…”

“…Previous studies report survival of horses with bacterial pneumonia as low as 46% 11 with more current studies reporting survival in up to 90% of cases. 11,[16][17][18] In our study, survival to discharge in horses <1 year of age was 79% (15/19), whereas overall survival to discharge in adults was 63% (17/27). Although age group was not significantly associated with survival, prognosis for adults infected with K. pneumoniae as the primary organism was poor, with survival in this population decreased at 52% (11/21).…”

“…Tachycardia and leukopenia were negatively associated with survival in our study population, but this association was not significant. Previous studies in foals found that a diagnosis of SIRS was associated with pulmonary infiltrates within the caudodorsal lung . Interestingly, the most common distribution of radiographic lesions in adults and foals in this study was in the caudodorsal lung field.…”

Low-field magnetic resonance anatomic features of the neonatalfoal thorax: an ex vivo study

“…Manipulation of the relative signal intensities of normal and abnormal tissue through appropriate use of MRI pulse sequences, the absence of ionizing radiation, and the ability to acquire images in nonaxial imaging planes are the relative advantages of MRI over CT (4,5). The evaluation of anatomic structures of the thorax is laborious due to its complex organization, which makes it difficult to diagnose morphologic alterations by means of physical examination and conventional radiographic studies (6). MRI may be a good alternative to conventional radiology.…”