Acute lung injury/acute respiratory distress syndrome in 15 foals.

This study explores the occurrence and treatment outcomes of Acute Lung Injury (ALI) and Acute Respiratory Distress Syndrome (ARDS) in foals aged between 1 to 12 months, conditions that have been well-documented in human medicine, but less so in veterinary medicine. The conditions were observed in fifteen foals, indicating ALI/ARDS symptoms that typically manifested as severe respiratory distress.

Objective and Methodology

• The research aimed to examine the history, clinical and laboratory findings, treatment, and outcome of foals diagnosed with ALI/ARDS at a referral hospital.
• The study employed a retrospective review of medical records, including radiographic, cytological, microbiological, serological, and post mortem findings.
• Foals included in the study had acute onset of respiratory distress, a ratio of partial pressure of arterial oxygen (PaO2) to the fraction of inspired oxygen (FiO2) of less than or equals to 300 mmHg, and thoracic radiographs or post mortem findings consistent with ALI/ARDS.

Results

• 15 foals, aged between 1.5 to 8 months, were part of the study. Out of these, seven had prior treatment for respiratory disease, and all developed acute respiratory distress within 48 hours before presentation.
• All foals exhibited symptoms of tachycardia and tachypnea, with eight cases of fever recorded. Eight foals met criteria for ALI, and seven for ARDS.
• Radiographic findings showed a diffuse bronchointerstitial pattern with focal to coalescent alveolar radiopacities, suggesting lung damage consistent with ALI/ARDS symptoms.
• An etiological agent causing the disease was identified in 6 foals while alive and 4 foals post mortem.
• All the foals were treated with intranasal oxygen, antimicrobial drugs, and 13 received corticosteroids. Four foals died due to respiratory failure, two were euthanized, and nine recovered fully after treatment.
• Follow-up demonstrated that the recovered foals were performing at a similar level to their peers, with one being a successful racehorse.

Conclusions

• The study concludes that there exists a condition in foals aged 1 to 12 months that closely aligns with the human criteria for ALI/ARDS, and it could be identical to previously described acute bronchointerstitial pneumonia in young horses.
• The findings suggest that treatment with systemic corticosteroids, intranasal oxygen, and antimicrobials might be beneficial for foals displaying clinical signs compatible with ALI/ARDS.
• The study further suggests that ALI/ARDS should be considered as a potential diagnosis in foals that present with acute severe respiratory distress and hypoxemia, and do not significantly respond to intranasal oxygen therapy.