Objective—To compare physiologic, hematologic,
and selected serum and plasma biochemical variables
obtained from horses competing in 48-, 83-, or 159-
km endurance rides before competition and at the
same cumulative distance points.
Procedure—Weight and rectal temperature measurements
and blood samples were obtained from horses
before, during, and after 1 of 3 rides conducted on the
same day. Plasma protein (PP), lactate, WBC, serum
electrolyte, and calcium concentrations; PCV; and
creatine kinase (CK) activity were determined.
Assessments were made to determine whether any
differences among groups, with respect to total distance
competed, could be explained by differences in
lap speed or conditioning and to investigate the effect
of time in transit or on-site prior to competition on
results of blood analyses or competition outcome.
Results—Horses in the 159-km distance group had
the lowest preride serum sodium, chloride, bicarbonate,
and calcium concentrations. As hours in transit
increased, preride PP concentration was significantly
greater; serum sodium, chloride, and bicarbonate concentrations
were lower; CK activity at 159 km was
greater; and horses were more likely to be eliminated.
The preride sodium was significantly greater in horses
that completed the ride, compared with those
Conclusions and Clinical Relevance—Among distance
groups, distance ridden, speed, level of fitness,
and years of experience of horses had little effect on
the variables examined. Electrolyte and water supplementation
and earlier arrival at the event may be beneficial
for horses that are transported long distances
to endurance competition. (Am J Vet Res 2003;64:746–753)
Objective—To determine plasma endotoxin concentration
in horses competing in a 48-, 83-, or 159-km
endurance race and its importance with regard to
physical, hematologic, or serum and plasma biochemical
Procedure—Weight and rectal temperature measurements
and blood samples were obtained before, during,
and after exercise. Blood samples were analyzed
for plasma endotoxin concentration; serum antiendotoxin
antibody titers; thromboxane B2 (TxB2) and 6-
keto-prostaglandin F1α (PGF1α) concentrations; tumor
necrosis factor alpha (TNFα) and interleukin-6 (IL-6)
activities; WBC, plasma protein, lactate, serum electrolyte,
and calcium concentrations; PCV; and creatine
Results—Detection of plasma endotoxin increased
during exercise for horses competing at all distances
but occurred more frequently in the 48- and 83-km
groups. Plasma lactate concentration was significantly
greater when endotoxin was concurrently detected.
Endotoxin in plasma was not significantly associated
with success of race completion. Plasma TxB2
and PGF1α concentrations and serum IL-6 activity significantly
increased with exercise. Horses that had an
excellent fitness level (as perceived by their owners)
had greater decreases in serum antiendotoxin antibody
titers during exercise than did horses perceived
as less fit. In horses with better finish times, TxB2 and
PGF1α concentrations were significantly greater and
TNFα activity was significantly less than that of slower
Conclusions and Clinical Relevance—Endotoxemia
developed during endurance racing, but was significantly
correlated with increased plasma lactate concentration
and not with other variables indicative of
endotoxemia. Plasma TxB2 and PGF1α concentrations
and serum TNFα activity may be associated with performance
success. (Am J Vet Res 2003;64:754–761)
Objective—To determine prevalence of resistance to
all anthelmintics that are commonly used to treat gastrointestinal
nematodes (GINs) in goats.
Procedure—On each farm, goats were assigned to 1
of 5 treatment groups: untreated controls, albendazole
(20 mg/kg [9.0 mg/lb], PO, once), ivermectin (0.4
mg/kg [0.18 mg/lb], PO, once), levamisole (12 mg/kg
[5.4 mg/lb], PO, once), or moxidectin (0.4 mg/kg, PO,
once), except on 3 farms where albendazole was
omitted. Fecal samples were collected 2 weeks after
treatment for determination of fecal egg counts
(FECs), and percentage reductions were calculated
by comparing data from anthelmintic-treated and
control groups. Nematode populations were categorized
as susceptible, suspected resistant, or resistant
by use of guidelines published by the World
Association for the Advancement of Veterinary
Results—Resistance to albendazole was found on 14
of 15 farms, and resistance to ivermectin, levamisole,
and moxidectin was found on 17, 6, and 1 of 18 farms,
respectively. Suspected resistance to levamisole and
moxidectin was found on 4 and 3 farms, respectively.
Resistance to multiple anthelmintics (albendazole and
ivermectin) was found on 14 of 15 farms and to albendazole,
ivermectin, and levamisole on 5 of 15 farms.
Mean overall FEC reduction percentages for albendazole,
ivermectin, levamisole, and moxidectin were 67,
54, 94, and 99%, respectively.
Conclusions and Clinical Relevance—Anthelmintic
resistance in GINs of goats is highly prevalent in the
southern United States. The high prevalence of resistance
to multiple anthelmintics emphasizes the need
for reexamination of nematode control practices.
(J Am Vet Med Assoc 2003;223:495–500)
Objective—To compare the performance of 3 point-of-care glucose meters in adult and juvenile alpacas with that of a laboratory-based analyzer.
Animals—35 adult alpacas and 21 juvenile alpacas.
Procedures—Whole blood samples obtained via jugular venipuncture were tested with all 3 point-of-care glucose meters; plasma samples were also tested with 1 of those meters. Glucose concentrations determined by use of the point-of-care meters were compared with results from the laboratory-based analyzer.
Results—Plasma glucose concentrations determined by use of the laboratory-based analyzer ranged from 36 to 693 mg/dL. Over the entire range of glucose concentrations tested, the Lin concordance correlation coefficient (agreement) was significant and excellent for all comparisons. Concordance decreased for 1 glucometer when testing whole blood samples over a narrower range of glucose concentrations (50 to 200 mg/dL). Bias was typically small (< 10 mg/dL) for 3 of the 4 comparisons but considerable for 1 meter with the use of whole blood. The limits of agreement were wide for all comparisons over the entire range of glucose concentrations tested but decreased to within acceptable limits when the narrower glucose range (50 to 200 mg/dL) was analyzed for 3 of the comparisons. For samples with a PCV < 25%, bias and the limits of agreement were greater for one of the meters tested.
Conclusions and Clinical Relevance—Discrepancies between point-of-care glucose meters and reference techniques can be considerable in alpacas, emphasizing the importance of assessing individual meter performance in a target population.
Objective—To determine prevalence of anthelmintic resistance on sheep and goat farms in the southeastern United States.
Animals—Sheep and goats from 46 farms in 8 southern states, Puerto Rico, and St Croix in the US Virgin Islands.
Procedures—Parasite eggs were isolated from fecal samples, and susceptibility to benzimidazole, imidathiazole, and avermectin-milbemycin anthelmintics was evaluated with a commercial larval development assay.
Results—Haemonchus contortus was the most common parasite on 44 of 46 farms; Trichostrongylus colubriformis was the second most commonly identified parasite. Haemonchus contortus from 45 (98%), 25 (54%), 35 (76%), and 11 (24%) farms were resistant to benzimidazole, levamisole, ivermectin, and moxidectin, respectively. Resistance to all 3 classes of anthelmintics was detected on 22 (48%) farms, and resistance to all 3 classes plus moxidectin was detected on 8 farms (17%).
Conclusions and Clinical Relevance—Findings provided strong evidence that anthelmintic resistance is a serious problem on small ruminant farms throughout the southeastern United States. Owing to the frequent movement of animals among regions, the prevalence of resistance in other regions of the United States is likely to also be high. Consequently, testing of parasite eggs for anthelmintic resistance should be a routine part of parasite management on small ruminant farms.