trained veterinarians with the help of Nicaraguan veterinary students. At a minimum, the following
information was collected: the horse’s age in years,
body condition score (BCS) from 1–9 on the Henneke
Scale, temperature (in Fahrenheit), pulse, respira-
tion, mucous membrane color (MM), and estimated
numbers of external parasites (ticks) were recorded.
Whenever possible, photos of the horses were taken
to help ensure that body condition scoring was con-
sistent across the different veterinarians. Blood and fecal samples were taken to be pro-
cessed or submitted for the following:
flPacked cell volume (PCV)
flPlasma total solids (TS) via refractometer
flBlood smear evaluation
flQuantitative fecal flotation via McMaster
chamber
flEquine infectious anemia (EIA) via agar gel
immuno-diffusion (AGID)
flBabesia caballi via cELISA
awith polymerase
chain reaction (PCR) followup
flTheileria equi via cELISA
awith PCR followup
Samples were processed the same day they
were collected. Serum was separated and refriger-
ated, and whole blood was used to make a blood
smear and determine PCV and TS. All readings for
PCV and TS were performed by the author. Blood
smears were later stained
band evaluated by the
author for presence of hemoparasites. Differential
counts were not performed. All serology was per-
formed the following week, at the diagnostic labora-
tory of the Universidad Nacional de Costa Rica in
Heredia, due to lack of diagnostic capabilities in
Nicaragua and difficulty in obtaining permits to
bring samples back to the United States. Fecal
samples were refrigerated during storage and pro-
cessed by the author using standard technique for
quantitative fecal flotation using a McMaster count-
ing chamber.
3. Results
The sample set of 35 horses included 10 mares, 10
stallions and 15 geldings (Table 1). Ages ranged
from 1 to 19 years with an average of 8.4 years.
Body condition ranged from 1.5 to 5 of 9 on the
Henneke scale, with an average of 2.9/9. The aver-
age body condition varied slightly by community:
Granada averaged 2.9/9, Managua 3/9, La Paz Cen-
tro 2.6/9, and Ometepe 3.1/9. The majority of horses (33/35 or 94%) were classi-
fied as anemic with a PCV less than 32%, and the
average PCV was 26.6%. The average value of to-
tal plasma solids was 7.0 g/dL with a range of 6.4 to
9.3 g/dL. No animals were found to be hypopro-
teinemic. The subjective classification of mucous
membrane color as “pink” or “pale” was a weak
predictor of actual PCV. For the 20 horses classi-
fied as “pink”, the PCV value ranged from 20 to 37%
with an average of 26.8%. For the 13 horses clas- sified as “pale”, the PCV ranged from 15–30% with
an average of 26.1%. BCS did not correlate to PCV
(Fig. 1). However, the three horses with the high-
est PCV (all
\630%) also had body condition scores of
4/9, which is higher than the average of 2.9/9. The AGID test for EIA was positive in four of 35
samples, for an overall prevalence rate of 11%.
However, three of four positives were found in
Granada (38% local prevalence rate) and no posi-
tives were recorded in Managua or Ometepe. The
average PCV for the four positive horses was 22%,
lower than the overall average of 26.6% and the
average BCS was also lower than average at 2.4/9. Evaluation of the blood smears did not reveal any
hemoparasites, but various indicators of anemia
were frequently observed, such as anisocytosis,
marked rouleaux formation, and increased central
pallor of red blood cells. Almost all horses (34/35, or 97%) were positive on
the cELISA screening test for one or both of the
organisms that cause equine piroplasmosis; co-
infections were common. The predominant organ-
ism varied by community, as shown in Fig. 2. In
Granada, 63% were positive for B. caballiand 100%
were positive for T. equi; in Managua, 60% were
positive for B. caballiand 80% were positive for T.
equi; in La Paz Centro, 83% were positive for B.
caballi and 58% were positive for T. equi; and in
Ometepe, 100% were positive for B. caballiand 20%
were positive for T. equi. When the horses were
grouped by cELISA status, there were modest dif-
ferences in body condition and PCV value. The six
animals that tested positive for only T. equishowed
a lower-than-average PCV (24.5%) but a higher-
than-average BCS (3.1/9); the 13 animals positive
for only B. caballi had a higher-than-average PCV
(28.5%) and an average BCS (2.8/9); the 15 animals
positive for both organisms were close to the general
averages at 26.2% and 2.9/9, respectively. The one
horse that was negative for both T. equiandB.
caballi was also negative for EIA, and yet was still
moderately anemic with a PCV of 23% and a BCS of
2.5/9. Due to financial limitations, only a subset of pos-
itive samples were selected for follow-up PCR to
investigate what percentage of positive animals ei-
ther had active piroplasmosis or were serving as
reservoirs for the organism. For B. caballi, 13 sam-
ples with positive cELISA were also submitted for
follow-up PCR, and only one tested positive (7.7%).
For T. equi, 12 samples with positive cELISA were
submitted for follow-up PCR and seven were found
to be positive (58.3%). Of the seven animals with
positive cELISA and PCR results, the average BCS
was 2.6/9; the average BCS for the five horses that
were cELISA positive and PCR negative was 3.6/9. Fecal flotation revealed strongyle eggs in 24 of 29
samples (83%). Of the 24 samples with strongyles,
five samples had less than 500 eggs per gram (EPG)
and were classified as low shedders; 14 samples had
from 500-1150 EPG and were classified as moderate
338 2015fiVol. 61fiAAEP PROCEEDINGS
EQUITARIAN SESSION