Effect of an external nasal dilator strip on cytologic characteristics of bronchoalveolar lavage fluid in Thoroughbred racehorses.
OBJECTIVE
To determine the effects of an external nasal dilator strip on cytologic characteristics of bronchoalveolar lavage (BAL) fluid in racing Thoroughbreds.


METHODS
Clinical trial.


METHODS
23 Thoroughbred racehorses in active training.


METHODS
Each horse raced on 2 occasions: once while wearing an external nasal dilator strip and once while not. Bronchoalveolar lavage was performed 12 to 18 hours after each race, and BAL fluid was analyzed for RBC and leukocyte counts and hemosiderin content.


RESULTS
Mean +/- SEM count of RBCs in BAL fluid when horses raced without the nasal dilator strip (84.6 +/- 275 cells/microL) was not significantly different from count when they raced with it (41.7 +/- 12.2 cells/microL). Horses were grouped as having mild or severe bleeding on the basis of RBC count in BAL fluid after horses raced without the nasal dilator strip. Mean count when horses with severe bleeding raced without the nasal dilator strip (271.0 +/- 63.7 cells/microL) was significantly higher than mean count when these horses raced with the strip (93.8 +/- 376 cells/microL). Mean count of lymphocytes in BAL fluid was significantly lower after horses raced with the external nasal dilator strip.


CONCLUSIONS
Results suggest that use of an external nasal dilator strip in Thoroughbred racehorses may decrease pulmonary bleeding, particularly in horses with severe exercise-induced pulmonary hemorrhage.
Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
Sandra C
SC
Valdez
Jorge E
JE
Nieto
Sharon J
SJ
Spier
Sean D
SD
Owens
Pablo
P
Beldomenico
Jack R
JR
Snyder
D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology*; D004106:Dilatation / Q000295:instrumentation / Q000379:methods / Q000662:veterinary*; D004906:Erythrocyte Count / Q000662:veterinary; D005260:Female; D006470:Hemorrhage / Q000517:prevention & control / Q000662:veterinary*; D006485:Hemosiderin / Q000032:analysis; D006734:Horse Diseases / Q000517:prevention & control*; D006736:Horses / Q000502:physiology*; D007958:Leukocyte Count / Q000662:veterinary; D008297:Male; D009296:Nasal Cavity / Q000502:physiology; D009666:Nose; D010805:Physical Conditioning, Animal / Q000502:physiology*; D012123:Pulmonary Ventilation / Q000187:drug effects
D006485:Hemosiderin