Department of Animal Science Florida Agricultural
Research Report AL-1982-8 Experiment Station
August, 1982 Gainesville, Florida

PREVALENCE OF EXERCISE ASSOCIATED PULMONARY
HEMORRHAGE (EAPH) IN RACING QUARTER HORSES
AND APPALOOSAS IN FLORIDA

R.L. Asquith, E.L. Johnson,
C.J. Hillidge and T.J. Lane
The recognition of "bleeding" in the racehorse dates back at least to the 16th
century, and is historically recorded in the grandsire of the immortal Eclipse. For
years this phenomenon was also referred to as epistaxis and based upon the observation
that the horse exhibited visible bleeding from either one or both nostrils after ex-
ercise or racing. This would suggest that the origin of the blood was from the nasal
cavity of the horse. Cook (1972) suggested that at least in part this blood originated
from the lungs and finally with the introduction of the flexible fiberoptic endoscope
others determined the major source of the blood was in fact the lungs. These findings
prompted the term exercised induced"pulmonary hemorrhage (EIPH), based upon the
description by Pascoe et al (1981). The investigators in this report, suggest that
exercise associated pulmonary hemorrhage (EAPH) may be more appropriate terminology.

The frequency of EAPH has been reported in Australia, England, South Africa and
the United States. Surveys have been conducted at racetracks on both Thoroughbreds
and Standardbreds at several geographic locations in the United States. Although
racing Quarter Horses have been known to exhibit this phenomenon, the frequency of
EAPH in this breed and Appaloosas is being reported for the first time in this study.

Experiment
The University of Florida Equine Performance Group (EPG) conducted a trial to
determine the frequency of EAPH in Quarter Horses racing at Pompano Park during the
1982 summer race meet.

Trainers were petitioned to allow the investigators to conduct endoscopic ex-
aminations-of their horses following racing. Those volunteering their horses enabled
this group to examine 231 horses. The length of the races were from 350 to 870 yards.
The horses were examined either in the state's detention barn or in their own stall
between 30 and 90 minutes after their race, regardless of their placement of finish.
Both nostrils were examined for evidence of visual bleeding, then by restraint with a
nose twitch a 100cm flexible fiberoptic endoscope was inserted into one of the nostrils
and passed slowly along the ventral meatus to the caudal part of the nasal cavity. The
endoscope was slowly advanced while examining all visible structures well into the
nasopharynx, through.the rima glottidis and well into the tracheal lumen. Any deviation
from normal was recorded along with the degree of hemorrhage if observed and the
amount of debris.

Asquith, Associate Professor; Johnson, Assistant Professor, Department of Animal
Science.
2Hillidge, Associate Professor; Lane, Assistant Professor, College of Veterinary
Medicine.

page 2

Within this population of horses examined there were 93 two-year olds (40.2%),
83 were three-year olds (35.9%), 36 four-year olds (15.6%),and 19 horses that were
five-years old or older (8.3%). The sex distribution was represented by 102 geld-
ings (44.1%), 67 fillies or mares (29.1%), and 62 colts or stallions (26.8%).

Results and Discussion
This study revealed that 144 horses or 62.3% (Fig. 1) of.those examined ex-
hibited some degree of internal bleeding that ranged from mild to profuse.

The incidence of EAPH by the age groups examined is shown in (Fig. 2). Although
this may not necessarily demonstrate an association between the horse's..age and EAPH,
the results are interesting and suggest a specific trial with a greater number of
horses within these breeds may be warranted.

Other surveys conducted with Thoroughbred and Standardbreds (Pascoe et al,
1981) suggest that a trend may exist toward an increased frequency of EAPHiwTiTh
age, and a significant association between the distance raced and the frequency of
bleeding (Raphel;and Soma, 1982). The present study establishes the importance
of the incidence of EAPH in racing Quarter Horses and Appaloosas as a clinical enity
and the need for further investigations.

Literature Cited
1. Cook, W.R. Epistaxis in the racehorse. Equine Vet J 6:45-58, 1974.

2. Pascoe, J.R., Ferraro, G.L., Cannon, J.H., Arthur, R.M., and Wheat, J.D.
Exercise-Induced Pulmonary Hemorrhage in racing Thoroughbreds: a preliminary
study. Am J Vet.Res 42:703-707, 1981.
3. Raphel, C.F. and Soma, L.R. Exercise-induced pulmonary hemorrhage in
Thoroughbreds after racing and breezing. Am J Vet Res 43:1123-1127, 1982.

page 2

Within this population of horses examined there were 93 two-year olds (40.2%),
83 were three-year olds (35.9%), 36 four-year olds (15.6%),and 19 horses that were
five-years old or older (8.3%). The sex distribution was represented by 102 geld-
ings (44.1%), 67 fillies or mares (29.1%), and 62 colts or stallions (26.8%).

Results and Discussion
This study revealed that 144 horses or 62.3% (Fig. 1) of.those examined ex-
hibited some degree of internal bleeding that ranged from mild to profuse.

The incidence of EAPH by the age groups examined is shown in (Fig. 2). Although
this may not necessarily demonstrate an association between the horse's..age and EAPH,
the results are interesting and suggest a specific trial with a greater number of
horses within these breeds may be warranted.

Other surveys conducted with Thoroughbred and Standardbreds (Pascoe et al,
1981) suggest that a trend may exist toward an increased frequency of EAPHiwTiTh
age, and a significant association between the distance raced and the frequency of
bleeding (Raphel;and Soma, 1982). The present study establishes the importance
of the incidence of EAPH in racing Quarter Horses and Appaloosas as a clinical enity
and the need for further investigations.

Literature Cited
1. Cook, W.R. Epistaxis in the racehorse. Equine Vet J 6:45-58, 1974.

2. Pascoe, J.R., Ferraro, G.L., Cannon, J.H., Arthur, R.M., and Wheat, J.D.
Exercise-Induced Pulmonary Hemorrhage in racing Thoroughbreds: a preliminary
study. Am J Vet.Res 42:703-707, 1981.
3. Raphel, C.F. and Soma, L.R. Exercise-induced pulmonary hemorrhage in
Thoroughbreds after racing and breezing. Am J Vet Res 43:1123-1127, 1982.

Fig. 1 Percent of EAPH positive horses in the survey.

100-

80 -

60-

40-

20-

070/

790/

67%

A nl

2 3 4 5 and up
Age years

Fig. 2 Relationship of frequency of EAPH to age.

Fig. 1 Percent of EAPH positive horses in the survey.

100-

80 -

60-

40-

20-

070/

790/

67%

A nl

2 3 4 5 and up
Age years

Fig. 2 Relationship of frequency of EAPH to age.