Objective—To examine the effects of various doses
of mosapride, a 5-hydroxytryptamine 4 receptor agonist,
on motility of the small intestine and cecum in
horses by use of electrical activity and to determine
the dose that provides the optimal response.
Animals—6 healthy adult Thoroughbreds.
Procedure—Electrical activity of the small intestine
and cecum was recorded before and after mosapride
administration by use of an electrogastrograph.
Mosapride (0.5, 1, 1.5, and 2 mg/kg) was dissolved in
200 mL of water and administered orally to horses
through a nasogastric tube. Three hours after drug
administration, mean amplitude of electrical activity
calculated for a period of 30 minutes was expressed
as the percentage of the mean amplitude of electrical
activity for a period of 30 minutes before drug
Results—Mosapride administered orally increased
the percentage of the mean amplitude of electrical
activity in the small intestine and cecum in a dosedependent
manner. Mean ± SD values differed significantly
for 1, 1.5, and 2 mg/kg (127.0 ± 12.5%, 137.7 ±
22.2%, and 151.1 ± 24.0%, respectively) in the small
intestine and for 1.5 and 2 mg/kg (130.1 ± 34.5% and
151.6 ± 45.2%, respectively) in the cecum.
Conclusions and Clinical Relevance—Analysis of
results of this study clearly documents that
mosapride promotes motility in the small intestine
and cecum of horses and that the optimal orally
administered dosage is 1.5 to 2 mg/kg. Therefore,
mosapride may be useful for treatment of horses
with gastrointestinal tract dysfunction. (Am J Vet Res 2005;66:1321–1323)
Objective—To evaluate effectiveness of allogeneic bone screws and pins for internal fixation of midbody transverse fractures of equine proximal sesamoid bones (PSBs) in vitro.
Sample Population—14 forelimbs from cadavers of 3-year-old Thoroughbreds.
Procedures—Allogeneic cortical bone fragments were collected from the limbs of a male Thoroughbred, and cortical bone screws were prepared from the tissue by use of a precision desktop microlathe programmed with the dimensions of a metal cortical bone screw. A midbody transverse osteotomy of each PSB was performed by use of a bone-shaping oscillating saw and repaired via 1 of 3 internal fixation techniques: 1 allogeneic bone screw with 1 allogeneic bone pin (type I; n = 6 PSBs), 2 allogeneic bone screws (type II; 8), or 1 stainless steel cortical bone screw (control repair; 6). Mechanical tension measurements were obtained by use of a commercially available materials testing system.
Results—Mean ± SD tensile strength (TS) was 668.3 ± 216.6 N for type I repairs, 854.4 ± 253.2 N for type II repairs, and 1,150.0 ± 451.7 N for control repairs.
Conclusions and Clinical Relevance—Internal fixation of PSB fractures by the use of allogeneic bone screws and bone pins was successful. Although mean TS of control repairs with stainless steel cortical bone screws was greater than the mean TS of type I and type II repairs, the difference between type II and control repairs was not significant. Allogeneic screws may advance healing and result in fewer complications in a clinical setting.
Objective—To evaluate the effect of intra-articular injection of gelatin hydrogel microspheres containing basic fibroblast growth factor (bFGF) on experimentally induced defects in third metacarpal bones (MC3s) of horses, in vivo.
Animals—6 healthy adult Thoroughbreds.
Procedures—Horses were anesthetized, and a hole (diameter, 4.5 mm) was drilled into the medial condyle of both MC3s of each horse. One milliliter (100 μg) of a solution of gelatin hydrogel microspheres (2 mg) containing bFGF was injected into the joint capsule of the right metacarpophalangeal joint of each horse (bFGF joint). One milliliter of saline (0.9% NaCl) solution was injected into the left metacarpophalangeal joint (control joint). Radiography was performed 1 day and 4, 8, 12, and 16 weeks after surgery to evaluate bone defect refilling. Sixteen weeks after surgery, multidetector-row computed tomography (MDRCT) was performed to determine the degree of refilling at the bone defect site.
Results—Radiography revealed healing of bone defects at 4 to 12 weeks after surgery in bFGF joints and at 8 to 16 weeks after surgery in control joints. In addition, MDRCT revealed a higher degree of healing in bFGF versus control joints. Mean ± SD MDRCT score for bFGF joints (411.7 ± 135.6 Hounsfield units) was significantly higher than that for control joints (240.8 ± 133.1 Hounsfield units).
Conclusions and Clinical Relevance—Treatment of horses with gelatin hydrogel microspheres that contained bFGF enhanced bone regeneration and healing of experimentally induced defects. This treatment strategy may be useful for treating horses with fractures.
Procedure—Each of the cattle was restrained in a
standing position. Height of the second lumbar vertebra's
transverse process (2LTP) and humeral tuberosity
(HT) on the right side as well as abdominal girth
(AG) were measured in each animal, and body condition
score (BCS) was ascertained. Skin caudal to the
first lumbar spinous process was aseptically prepared,
and anesthetic was injected. After inserting a
16-gauge 120-mm Tuohy needle in the ligamentum
flavum, a calibrated pressure transducer was connected
to the needle. Then, the needle was introduced
into the epidural space, and epidural pressure
Results—Mean ± SD residual epidural pressure of
heifers (–9.3 ± 3.3 mm Hg) was significantly higher than
that of lactating (–17.4 ± 5.5 mm Hg) or nonlactating
(–14.5 ± 2.4 mm Hg) cows. Stepwise regression of 5
variables revealed that only the difference in height
between 2LTP and HT (2LTP – HT) in heifers and only
BCS in lactating cows were significantly correlated with
residual epidural pressure. For all cattle, the optimal
equation (R2 = 0.47) describing the relationship was
y = –12.7 + 6.3x1 – 0.4x2 – 0.1x3, where y is epidural
pressure, x1 is BCS, x2 is 2LTP – HT, and x3 is age.
Conclusions and Clinical Relevance—Negative
epidural pressure was detected in standing cattle.
Growth, maturity, and pregnancy affect epidural pressure
in cattle. (Am J Vet Res 2002;63:954–957)