Objective—To investigate the effects of buprenorphine on cardiopulmonary variables and on abdominal auscultation scores in horses.
Animals—6 healthy adult horses.
Procedures—Horses were restrained in stocks and allocated to 2 treatments in a randomized crossover design, with 1-week intervals between each treatment. Saline (0.9% NaCl) solution was administered IV as a control, whereas buprenorphine (10 μg/kg, IV) was administered to the experimental group. Cardiopulmonary data were collected for 120 minutes after buprenorphine or saline solution administration. Abdominal auscultation scores were monitored for 2 and 12 hours after drug administration in the control and experimental groups, respectively.
Results—Following control treatment, horses remained calm while restrained in the stocks and no significant changes in cardiopulmonary variables were observed throughout the study. Buprenorphine administration caused excitatory phenomena (restlessness and head shaking). Heart rate, cardiac index, and arterial blood pressure were significantly increased after buprenorphine administration until the end of the observational period (120 minutes). Minimal changes were found in arterial blood gas tensions. Abdominal auscultation scores decreased significantly from baseline for 4 hours after buprenorphine administration.
Conclusions and Clinical Relevance— Buprenorphine induced excitement and hemodynamic stimulation with minimal changes in arterial blood gas tensions. These effects may impact the clinical use of buprenorphine in horses. Further studies are indicated to investigate the effects of buprenorphine on gastrointestinal motility and fecal output.
Objective—To evaluate analgesic effects of epidurally administered neostigmine alone or in combination with morphine in dogs after ovariohysterectomy.
Animals—40 healthy bitches.
Procedures—After acepromazine premedication, anesthesia was induced. Dogs randomly received 1 of the following 4 epidural treatments 30 minutes before ovariohysterectomy (n = 10/group): saline (0.9% NaCl) solution (control), morphine (0.1 mg/kg), neostigmine (10 μg/kg), or morphine-neostigmine (0.1 mg/kg and 10 μg/kg, respectively). Analgesia was assessed for 24 hours after surgery by use of a visual analogue scale (VAS; scale of 0 to 10) or numeric descriptive scale (NDS; scale of 0 to 24) and by the need for supplemental analgesia (morphine [0.5 mg/kg, IM] administered when VAS was ≥ 4 or NDS was ≥ 8).
Results—Significantly more control dogs (n = 8) received supplemental analgesia, compared with the number of neostigmine-treated dogs (1); no dogs in the remaining groups received supplemental analgesia. Compared with values for the control dogs, the NDS scores were lower for morphine-neostigmine–treated dogs (from 2 to 6 hours and at 12 hours) and for morphine-treated dogs (all time points). The NDS scores were lower for morphine-treated dogs at 3, 12, and 24 hours, compared with values for neostigmine-treated dogs. The VAS was less sensitive than the NDS for detecting differences among groups.
Conclusions and Clinical Relevance—Epidurally administered neostigmine reduced the use of supplemental analgesia after ovariohysterectomy in dogs. However, analgesic effects were less pronounced than for epidurally administered morphine or morphine-neostigmine. Adding neostigmine to epidurally administered morphine did not potentiate opioid-induced analgesia.
Objective—To compare the ability of a sidestream
capnograph and a mainstream capnograph to measure
end-tidal CO2 (ETCO2) and provide accurate estimates
of PaCO2 in mechanically ventilated dogs.
Design—Randomized, double Latin square.
Animals—6 healthy adult dogs.
Procedure—Anesthesia was induced and neuromuscular
blockade achieved by IV administration of pancuronium
bromide. Mechanical ventilation was used
to induce conditions of standard ventilation, hyperventilation,
and hypoventilation. While tidal volume was
held constant, changes in minute volume ventilation
and PaCO2 were made by changing the respiratory
rate. Arterial blood gas analysis was performed and
ETCO2 measurements were obtained by use of either
a mainstream or a sidestream capnographic analyzer.
Results—A linear regression model and bias analysis
were used to compare PaCO2 and ETCO2 measurements;
ETCO2 measurements obtained by both
capnographs correlated well with PaCO2. Compared
with PaCO2, mainstream ETCO2 values differed by
3.15 ± 4.89 mm Hg (mean bias ± SD), whereas the
bias observed with the sidestream ETCO2 system
was significantly higher (5.65 ± 5.57 mm Hg).
Regardless of the device used to measure ETCO2,
bias increased as PaCO2 exceeded 60 mm Hg.
Conclusions and Clinical Relevance—Although the
mainstream capnograph was slightly more accurate,
both methods of ETCO2 measurement correlated
well with PaCO2 and reflected changes in the ventilatory
status. However, ETCO2 values > 45 mm Hg may
inaccurately reflect the severity of hypoventilation as
PaCO2 may be underestimated during conditions of
hypercapnia (PaCO2 > 60 mm Hg). (J Am Vet Med Assoc 2002;221:1582–1585)
Objective—To compare detomidine hydrochloride
and romifidine as premedicants in horses undergoing
Animals—100 client-owned horses.
Procedure—After administration of acepromazine
(0.03 mg/kg, IV), 50 horses received detomidine
hydrochloride (0.02 mg/kg of body weight, IV) and 50
received romifidine (0.1 mg/kg, IV) before induction
and maintenance of anesthesia with ketamine
hydrochloride (2 mg/kg) and halothane, respectively.
Arterial blood pressure and blood gases, ECG, and
heart and respiratory rates were recorded. Induction
and recovery were timed and graded.
Results—Mean (± SD) duration of anesthesia for all
horses was 104 ± 28 minutes. Significant differences
in induction and recovery times or grades were not
detected between groups. Mean arterial blood pressure
(MABP) decreased in both groups 30 minutes
after induction, compared with values at 10 minutes.
From 40 to 70 minutes after induction, MABP was
significantly higher in detomidine-treated horses,
compared with romifidine-treated horses, although
more romifidine-treated horses received dobutamine
infusions. In all horses, mean respiratory rate ranged
from 9 to 11 breaths/min, PaO2 from 200 to 300 mm
Hg, PaCO2 from 59 to 67 mm Hg, arterial pH from 7.33
to 7.29, and heart rate from 30 to 33 beats/min, with
no significant differences between groups.
Conclusions and Clinical Relevance—Detomidine
and romifidine were both satisfactory premedicants.
Romifidine led to more severe hypotension than detomidine,
despite administration of dobutamine to more
romifidine-treated horses. Both detomidine and romifidine
are acceptable α2-adrenoceptor agonists for
use as premedicants before general anesthesia in
horses; however, detomidine may be preferable
when maintenance of blood pressure is particularly
important. (Am J Vet Res 2001;62:359–363)
Objective—To investigate spontaneous locomotor activity (SLA) and antinociceptive effects of buprenorphine in horses.
Animals—6 healthy adult horses.
Procedures—Horses received each of 3 treatments (10 mL of saline [0.9% NaCl] solution, 5 μg of buprenorphine/kg, or 10 μg of buprenorphine/kg).Treatments were administered IV. Order of treatments was randomized, and there was a 10-day interval between subsequent treatments. Spontaneous locomotor activity was investigated in a behavioral box by use of infrared photoelectric sensors connected to a computer, which detected movement of each horse. Antinociceptive effect was investigated by hoof-withdrawal reflex latency (HWRL) and skin-twitching reflex latency (STRL) after painful stimulation with a heat lamp.
Results—Moderate excitement was observed in all horses from 5 to 10 minutes after the administration of both dosages of buprenorphine. The SLA increased significantly for 6 and 14 hours after IV administration of 5 and 10 μg of buprenorphine/kg, respectively. Values for HWRL increased significantly only at 30 minutes after injection of 5 μg of buprenorphine/kg, whereas STRL and HWRL each increased significantly from 1 to 6 hours (except at 2 and 4 hours) and 11 hours, respectively, after injection of 10 μg of buprenorphine/kg.
Conclusions and Clinical Relevance—IV injection of buprenorphine caused a dose-dependent increase in SLA, but only the dose of 10 μg/kg induced analgesia on the basis of results for the experimental method used.
Objective—To evaluate adverse effects of long-term oral administration of carprofen, etodolac, flunixin meglumine, ketoprofen, and meloxicam in dogs.
Animals—36 adult dogs.
Procedures—Values for CBC, urinalysis, serum biochemical urinalyses, and occult blood in feces were investigated before and 7, 30, 60, and 90 days after daily oral administration (n = 6 dogs/group) of lactose (1 mg/kg, control treatment), etodolac (15 mg/kg), meloxicam (0.1 mg/kg), carprofen (4 mg/kg), and ketoprofen (2 mg/kg for 4 days, followed by 1 mg/kg daily thereafter) or flunixin (1 mg/kg for 3 days, with 4-day intervals). Gastroscopy was performed before and after the end of treatment.
Results—For serum γ-glutamyltransferase activity, values were significantly increased at day 30 in dogs treated with lactose, etodolac, and meloxicam within groups. Bleeding time was significantly increased in dogs treated with carprofen at 30 and 90 days, compared with baseline. At 7 days, bleeding time was significantly longer in dogs treated with meloxicam, ketoprofen, and flunixin, compared with control dogs. Clotting time increased significantly in all groups except those treated with etodolac. At day 90, clotting time was significantly shorter in flunixin-treated dogs, compared with lactose-treated dogs. Gastric lesions were detected in all dogs treated with etodolac, ketoprofen, and flunixin, and 1 of 6 treated with carprofen.
Conclusions and Clinical Relevance—Carprofen induced the lowest frequency of gastrointestinal adverse effects, followed by meloxicam. Monitoring for adverse effects should be considered when nonsteroidal anti-inflammatory drugs are used to treat dogs with chronic pain.
Objective—To compare the effects of decompressive surgery (DSX), electroacupuncture (EAP), and DSX followed by EAP (DSX + EAP) for the treatment of thoracolumbar intervertebral disk disease (IVDD) in dogs with severe neurologic deficits of > 48 hours' duration.
Design—Retrospective case series and prospective clinical trial.
Animals—40 dogs between 3 and 6 years old and weighing between 10 and 20 kg (22 and 44 lb) with long-standing (> 48 hours) clinical signs of severe neurologic disease attributable to thoracolumbar IVDD.
Procedures—Thoracolumbar medullar injury was classified on the basis of neurologic signs by use of a scale ranging from 1 (least severe) to 5 (most severe). The DSX dogs (n = 10) were retrospectively selected from those that underwent DSX for the treatment of thoracolumbar IVDD. In addition, 19 dogs received EAP alone and 11 dogs underwent DSX followed by EAP (DSX + EAP). Outcome was considered a clinical success when a dog initially classified as grade 4 or 5 was classified as grade 1 or 2 within 6 months after the end of treatment.
Results—The proportion of dogs with clinical success was significantly higher for dogs that underwent EAP (15/19) than for dogs that underwent DSX (4/10); the proportion of dogs with clinical success for dogs that underwent DSX + EAP was intermediate (8/11).
Conclusions and Clinical Relevance—EAP was more effective than DSX for recovery of ambulation and improvement in neurologic deficits in dogs with long-standing severe deficits attributable to thoracolumbar IVDD.
OBJECTIVE To evaluate pain intensity and kinetic variables in dogs with hip dysplasia (HD) treated with acupuncture, carprofen, or a placebo.
DESIGN Randomized, controlled clinical study.
ANIMALS 54 HD-affected dogs and 16 healthy dogs.
PROCEDURES Seven HD-affected dogs were removed from the study. Dogs with HD were treated in a blinded manner for 30 days with acupuncture (once weekly for 5 sessions; n = 15), carprofen (4.4 mg/kg [2.0 mg/lb], PO, q 24 h; n = 16), or placebo capsules containing lactose (1 mg/kg [0.45 mg/lb], PO, q 24 h; n = 16). Dogs were evaluated 2 weeks and immediately before (baseline) and 2, 4, and 6 weeks after the onset of treatment. Owners evaluated the dogs' pain intensity with 2 validated questionnaires and a visual analogue scale (VAS) for pain and evaluated degree of lameness with a VAS for locomotion. Kinetics of the hind limbs were also evaluated. Sixteen HD-free dogs were used to assess the evaluation protocol.
RESULTS Owners' assessments revealed that outcomes of the 3 treatments did not differ significantly. The Canine Brief Pain Inventory and VAS pain intensity assessments were decreased from baseline at weeks 4 and 6, respectively, but only in acupuncture-treated dogs. The locomotion VAS values were decreased at week 4 in acupuncture-treated and carprofen-treated dogs. Kinetic evaluation findings did not differ among the groups or over time.
CONCLUSIONS AND CLINICAL RELEVANCE Neither acupuncture nor carprofen was significantly different from placebo. Acupuncture and carprofen reduced the degree of subjectively evaluated lameness, and acupuncture was associated with a decrease in validated chronic pain scores.