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ARS Home » Pacific West Area » Pullman, Washington » Animal Disease Research » Research » Publications at this Location » Publication #351784

Research Project: Development of Detection and Control Strategies for Bovine Babesiosis and Equine Piroplasmosis

Location: Animal Disease Research

Title: Exercise-induced pulmonary hemorrhage in barrel racing horses in the Pacific Northwest region of the United States

item Gold, Jenifer - Washington State University
item Knowles, Doanld - Collaborator
item Coffey, Todd - Washington State University
item Bayly, Warwick - Washington State University

Submitted to: Journal of Veterinary Internal Medicine
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/29/2018
Publication Date: 3/25/2018
Citation: Gold, J.R., Knowles, D.P., Coffey, T., Bayly, W.M. 2018. Exercise-induced pulmonary hemorrhage in barrel racing horses in the Pacific Northwest region of the United States. Journal of Veterinary Internal Medicine.

Interpretive Summary: Exercise-induced pulmonary hemorrhage (EIPH) is a serious problem of horses participating in performance related exercise. These data show that EIPH occurs in barrel racing horses, expanding the epidemiology of this exercise induced disease. Although the causes and/or pathways leading to EIPH are unknown but the correlation between red blood cells numbers in lung tissue and EIPH support the general thought that EIPH is a problem of blood vessel dynamics during strenuous exercise in the horse.

Technical Abstract: Background: Exercise-induced pulmonary hemorrhage (EIPH) refers to bleeding from the lungs in association with strenuous exercise. It has been documented in race horses but little information exists on EIPH in barrel racing horses. Hypothesis/Objectives: Our goals were to evaluate the presence of EIPH in barrel racing horses and estimate its prevalence in the Pacific Northwest. Animals: 149 barrel racing horses enrolled at events in WA (11), ID (3), and MT (33). Methods: Observational cross-sectional study. Data collected included signalment, history of illness, respiratory disease, race division, and pre-race medications. Endoscopy was performed and tracheobronchoscopic (TBE) EIPH score was assigned based on quantity of blood in the trachea (05no blood to 45abundance of blood within the trachea). After TBE, bronchoalveolar lavage (BAL) was performed. Erythrocyte (red blood cell, RBC) counts were obtained from bronchoalveolar lavage fluid (BALF). Statistical analysis included linear and logistic regression, Fisher’s exact t test, and calculation of correlation coefficient. Significance was set at P<.05. Results: The prevalence of EIPH based on TBE EIPH score was 54%. When based on BALF RBC count >1,000 cells, EIPH prevalence was 66%. Race time did not significantly affect the presence of EIPH. A significant (P<.0001) positive linear relationship between the TBE and BAL erythrocyte count was identified, but its strength was poor (r25.15). Conclusions and Clinical Importance: EIPH occurs in over 50% of barrel racing horses in the Pacific Northwest. Precise determination of the impact of EIPH on health of barrel racers requires further study.