Objective—To determine the effects of orally administered
glucosamine on concentrations of markers of
bone and cartilage metabolism in Standardbred horses
during race training.
Animals—Twenty 16- to 20-month-old Standardbreds
beginning race training.
Procedure—Horses were randomly assigned to 2
groups. One group received glucosamine hydrochloride
(4 g, PO, q 12 h), and the second (control) group
received glucose (4 g, PO, q 12 h). Serum samples
were obtained prior to onset of the study (baseline)
and at regular intervals for 48 weeks for determination
of concentrations of keratan sulfate (KS), osteocalcin
(OC), and pyridinoline crosslinks (PYD).
Results—Osteocalcin concentrations changed significantly
with time; mean serum concentrations were
significantly higher than baseline values for samples
obtained at 24 to 48 weeks after onset of the study.
Although a significant effect of time was observed for
mean concentration of KS, concentrations did not differ
significantly from baseline values at any time during
the study when groups were analyzed separately.
However, pooled analysis revealed significant increases
of mean serum KS concentration at weeks 24 and
30. Significant changes in serum PYD concentrations
were not detected. Oral administration of glucosamine
did not significantly affect serum concentrations
of any of the markers.
Conclusions and Clinical Relevance—Increased
serum OC in clinically normal Standardbreds during
race training may reflect bone formation that accompanies
adaptive remodeling of the appendicular skeleton.
For these experimental conditions, glucosamine did
not appear to exert a detectable influence on serum
concentrations of these 3 markers of connective tissue
metabolism. (Am J Vet Res 2002;63:1106–1110)
Objective—To assess the influence of preanesthetic
administration of acetylpromazine or morphine and
fluids on urine production, arginine vasopressin (AVP;
previously known as antidiuretic hormone) concentrations,
mean arterial blood pressure (MAP), plasma
osmolality (Osm), PCV, and concentration of total
solids (TS) during anesthesia and surgery in dogs.
Animals—19 adult dogs.
Procedure—Concentration of AVP, indirect MAP,
Osm, PCV, and concentration of TS were measured at
5 time points (before administration of acetylpromazine
or morphine, after administration of those
drugs, after induction of anesthesia, 1 hour after the
start of surgery, and 2 hours after the start of
surgery). Urine output and end-tidal halothane concentrations
were measured 1 and 2 hours after the
start of surgery. All dogs were administered lactated
Ringer's solution (20 ml/kg of body weight/h, IV) during
Results—Compared with values for acetylpromazine,
preoperative administration of morphine resulted in
significantly lower urine output during the surgical
period. Groups did not differ significantly for AVP concentration,
Osm, MAP, and end-tidal halothane concentration;
however, PCV and concentration of TS
decreased over time in both groups and were lower in
dogs given acetylpromazine.
Conclusions and Clinical Relevance—Preanesthetic
administration of morphine resulted in significantly
lower urine output, compared with values after
administration of acetylpromazine, which cannot be
explained by differences in AVP concentration or MAP.
When urine output is used as a guide for determining
rate for IV administration of fluids in the perioperative
period, the type of preanesthetic agent used must be
considered.(Am J Vet Res 2001;62:1922–1927)
Objective—To investigate differences in clinical variables among dogs with extrahepatic portosystemic shunts (EHPSSs) of various morphologies.
Design—Retrospective case series.
Animals—53 dogs with EHPSSs.
Procedures—Medical records of dogs undergoing preoperative CT angiography of an EHPSS over a 3-year period were reviewed. Analysis was performed to investigate relationships of clinical variables with shunt morphology. Morphologies were analyzed individually as well as in several groups.
Results—Shunt morphologies included 10 splenocaval, 9 splenophrenic, 11 splenoazygos, 10 right gastric-caval, 12 right gastric-caval with a caudal loop, and 1 right gastric-azygos with a caudal loop. Several biochemical variables associated with EHPSS were lowest in dogs with splenocaval shunts. Preoperative clinical signs were more common in dogs that had shunts with vena caval than right azygos vein insertion (36/41 [88%] vs 7/12 [58%]) and insertion caudal to the liver than diaphragmatic insertion (29/32 [91%] vs 14/21 [67%]). Neurologic signs were more common when shunts inserted into the vena cava caudal to the liver than in other locations (21/32 [66%] vs 6/21 [29%]) and were most frequent with splenocaval shunts. Urinary tract signs were more common when shunts had right gastric vein origin than gastrosplenic vein origin (14/23 [61%] vs 10/30 [33%]).
Conclusions and Clinical Relevance—Splenocaval shunts caused more clinical abnormalities than did other shunt morphologies. Results suggested that dogs with shunt insertion in the caudal vena cava, especially caudal to the liver, were most likely to have clinical signs.