Objective—To compare financial returns between
pinhooked yearling horses (ie, bought and trained for
approximately 5 months with the goal of selling the
horse at "2-year-olds in training" sales) that had mild
or severe training failure and horses that had planned
versus nonplanned training failure.
Procedure—During the period from September 1998
through and April 1999, 20 horses had mild training
failure (1 to 11 days lost), and 20 horses had severe
training failure (13 to 108 days lost). Horses were
assigned to these 2 groups on the basis of frequency
distribution (median) of days lost during training.
Horses were also categorized on the basis of type of
training failure (planned vs nonplanned training failure).
The outcome of primary interest was financial
return. Median financial returns were compared
among groups by use of the Mann-Whitney U test.
Results—Median financial returns for horses that had
severe training failure ($1,000) were significantly different,
compared with horses that had mild training
failure ($24,000). Analysis of results also indicated
that median returns were significantly different
among horses that had planned training failure
(−$2,000; eg, horses with radiographic abnormalities
detected during routine prepurchase examinations
that required surgical treatment, resulting in days lost
during training), compared with horses that did not
Conclusions and Clinical Relevance—Training failure
has an economic impact on revenues in pinhooked
yearling horses. Lameness, planned training
failure, respiratory disease, and ringworm were common
and important causes of training failure.
(Am J Vet Res 2001;62:1418–1422)
Objective—To compare 3 types of noxious stimuli
applied to various anatomic areas of anesthetized
dogs and rabbits for determination of the minimum
alveolar concentration (MAC).
Animals—10 dogs and 10 rabbits.
Procedure—Dogs were anesthetized with isoflurane
and halothane in a randomized order. Rabbits were
anesthetized with isoflurane. The MAC was determined
by skin incision on the lateral aspect of the
chest; clamping of the tail, paw of the forelimb, and
paw of the hind limb; and application of electrical current
to the oral mucosa (dogs only), forelimb, and hind
limb. The MAC was the end-tidal concentration midway
between the value permitting and preventing
purposeful movement in response to noxious stimuli.
Results—In dogs, mean ± SEM MAC for isoflurane
was 1.27 ± 0.05% for clamping stimuli, 1.36 ± 0.04%
for oral electrical stimulation, 1.35 ± 0.04% for electrical
stimulation to the limbs, and 1.01 ± 0.07% for surgical
incision. The MAC for halothane was 0.97 ±
0.03% for tail clamping, 0.96 ± 0.03% for clamping of
the limbs, 1.04 ± 0.03% for electrical stimulation, and
0.75 ± 0.06% for surgical incision. In rabbits, MAC for
isoflurane was 2.08 ± 0.02% for clamping stimuli,
2.04 ± 0.02% for electrical stimulation, and 0.90 ±
0.02% for surgical incision. The MAC for surgical incision
was significantly lower than values for the other
methods in both species.
Conclusions and Clinical Relevance—Use of electrical
current and clamping techniques resulted in similar
MAC values. Surgical incision underestimated
MAC values in dogs and rabbits. (Am J Vet Res
Objective—To evaluate horseshoe characteristics
and high-speed exercise history as risk factors for catastrophic
musculoskeletal injury in Thoroughbred
Animals—377 horses (37,529 race starts).
Procedure—Shoe characteristics included material,
toe grab height, heel traction device, pads, and rim
shoes. Racing variables were obtained from a computerized
database. Forty-three horses that had a
musculoskeletal injury and then failed to race or train
for 6 months (cases) and 334 noninjured horses from
the same race in which a horse was injured (controls)
were compared regarding risk factors.
Results—Overall, 98% of race starts were associated
with aluminum shoes, 85% with toe grabs, 32% with
pads, and 12% with rims on forelimb horseshoes.
Among 43 horses with musculoskeletal injury, sex
(geldings), an extended interval since last race, and
reduced exercise during the 30 or 60 days preceding
injury were risk factors for catastrophic injury. Odds
of injury in racehorses with toe grabs on front shoes
were 1.5 times the odds of injury in horses without
toe grabs, but this association was not significant
(95% confidence interval, 0.5 to 4.1).
Conclusions and Clinical Relevance—Results suggest
that horses that return to racing after an extended
period of reduced exercise are at high risk of catastrophic
musculoskeletal injury. Results regarding the
use of toe grabs as a possible risk factor for catastrophic
injury were inconclusive because the probability
of declaring (in error) that use of toe grabs was
associated with an increased risk of musculoskeletal
injury (eg, odds ratio > 1.0) was 38%. (Am J Vet Res 2005;66:1314–1320)
Objective—To determine whether passive transfer of
IgG in neonatal kittens affects plasma opsonic capacity
and neutrophil phagocytic and oxidative burst
responses to bacteria in vitro.
Animals—22 kittens from 6 specific pathogen-free
Procedure—Kittens were randomized at birth into the
following treatment groups: colostrum-fed,
colostrum-deprived, or colostrum-deprived supplemented
with feline or equine IgG. Blood samples
were collected at intervals from birth to 56 days of
age. Plasma IgG concentrations were determined by
radial immunodiffusion assay. Neutrophil function
was assessed by a flow cytometry assay providing
simultaneous measurement of bacteria-induced
phagocytosis and oxidative burst. The opsonic capacity
of kitten plasma was determined in an
opsonophagocytosis assay with bacteria incubated in
untreated or heat-inactivated plasma.
Results—Among treatment groups, there were no
significant differences in neutrophil phagocytic and
oxidative burst responses to bacteria or opsonic
capacity of plasma. In all samples of plasma, inactivation
of complement and other heat-labile opsonins
significantly reduced the opsonic capacity. Plasma
IgG concentrations in kittens did not correlate with
neutrophil function or plasma opsonic capacity before
or after inactivation of complement.
Conclusions and Clinical Relevance—The plasma
opsonic capacity and neutrophil phagocytic and oxidative
burst responses in vitro of kittens receiving passive
transfer of IgG via colostrum intake or IgG supplementation
and those deprived of colostrum were similar.
The alternate complement pathway or other heat-labile
opsonins may be more important than IgG in bacterial
opsonization and phagocytosis. ( Am J Vet Res
OBJECTIVE To compare pursestring, Witzel (seromuscular inversion), and seromuscular incision jejunostomy tube placement techniques in vitro.
SAMPLE Jejunal specimens from 10 dogs.
PROCEDURES Jejunal segments (50 cm) were harvested immediately prior to euthanasia from 10 mixed-breed dogs Specimens were harvested with the orad and aborad ends clamped and stored in saline (0.9% NaCl) solution–soaked towels during instrumentation. Three jejunostomy tubes were placed via 3 techniques (pursestring, Witzel, and seromuscular incision), and 2 double lumen central venous catheters were placed at each intestinal end for luminal filling and leak testing. Intestinal luminal area was measured ultrasonographically with specimens suspended in a warm undyed saline solution bath with the intestinal lumen filled with dyed saline solution (intraluminal pressure, 6 mm Hg). Leak testing was performed by means of infusion of dyed saline solution (4 mL/min) until each jejunostomy site failed. Intestinal luminal area and leakage pressure were compared between the 3 tube placement techniques.
RESULTS The Witzel and seromuscular incision techniques decreased the intestinal luminal area measured at the tube insertion site, albeit nonsignificantly. For the seromuscular incision technique, a significant decrease in intestinal luminal area at the intraluminal site of measurement was found. For 2/30 specimens (1/10 pursestring and 1/10 seromuscular incision), failure occurred at pressures within the range of previously reported peak peristaltic pressure for dogs. Failure occurred at supraphysiologic peristaltic pressures for the remaining 28 specimens, including all 10 specimens for the Witzel technique.
CONCLUSIONS AND CLINICAL RELEVANCE In this in vitro study, all specimens for the Witzel technique withstood physiologic peristaltic pressures during leak testing. Both tunneling techniques (Witzel and seromuscular incision) created a decrease in intestinal luminal area. Further investigation, including in vivo testing, is indicated to evaluate the clinical relevance of these findings.