Furosemide continuous rate infusion diluted with 5% dextrose in water or hypertonic saline in normal adult dogs: a pilot study

Objective

The goal of this study was to investigate the short-term safety and diuretic efficacy of furosemide constant rate infusion (CRI) diluted with 5% dextrose in water (D5W) compared to dilution with 2.4% hypertonic saline in healthy dogs.

Optimal filling solution for silicone Foley catheter balloons

We assessed whether saline, sterile water, or air better maintained filling volume and diameter in a veterinary silicone Foley bulb. The bulbs of 45 8-French silicone Foley catheters were inflated: 15 with 5 mL of sterile water (SW bulbs), 15 with 0.9% saline (S bulbs), and 15 with air (A bulbs). The bulbs were submerged in 30 mL of synthetic urine in a 50 mL conical tube in a 38°C water bath. Five catheters from each group were removed on days 3, 5, and 10 to measure bulb volume and diameter. On days 3 and 5, volume and diameter of SW or S bulbs were significantly greater than those of A bulbs, but were not significantly different from one another. At day 10, only 1 S bulb remained intact, 4 of the 5 SW bulbs were intact, the average volume of the SW bulbs was 2.8 mL, and the A bulbs were all deflated. We conclude that sterile water and 0.9% saline are both acceptable for Foley bulb inflation of 5 d or less, but sterile water might be preferred if bulb inflation must be maintained for more than 5 d.     

Effects of Four Preparations of 0.05% Chlorhexidine Diacetate on Wound Healing in Dogs

Four chlorhexidine diacetate (CHD) antiseptic wound lavage preparations were evaluated in vivo to determine their effects on second intention wound healing in the dog in vitro to determine their relative antibacterial activity against Staphylococcus intermedius. Chlorhexidine was diluted to 0.05% in sterile water, 0.9% sodium chloride, lactated Ringers solution (LRS), and LRS that was allowed to form a precipitate with CHD. Control solutions included sterile water and LRS. There were no significant differences in wound contraction or epithelialization. All 0.05% CHD preparations provided 100% bacterial kill.     

Response of pony peritoneum to four peritoneal lavage solutions

Peritoneal lavage was performed on ponies to determine the effect on peritoneal surfaces. Lavage solution (20 L) was introduced into each pony's peritoneal cavity through catheters placed in the paralumbar fossa, and the solution was removed by drainage from the ventral portion of the abdomen. Six ponies each were lavaged with sterile saline (0.9% NaCl) solution, sterile saline solution containing 5 X 10(6) U of potassium penicillin and 3 g of neomycin or povidone-iodine diluted to 3% by volume with sterile saline solution, and 3 ponies were lavaged with povidone-iodine diluted to 10% with sterile saline solution. Peritoneal lavage catheters were inserted in 3 control ponies, but lavage fluids were not administered. Peritoneal fluid specimens were collected at 6, 24, 48, and 96 hours after lavage. Nucleated cell counts, RBC counts, total protein determinations, and cytologic analysis were performed. The ponies were euthanatized at 96 hours, and representative sections of the peritoneum were examined. Lavage with saline solution and saline solution with antibiotics induced a mild, transient inflammatory response in the peritoneal fluid, with minimal or no changes observed at necropsy. Solutions containing povidone-iodine induced chemical peritonitis, which was severe in ponies lavaged with 10% povidone-iodine solution. Peritoneal lavage with povidone-iodine solutions as dilute as 3% cannot be accomplished without causing inflammation of peritoneal surfaces.     

Comparison of Intra-articular and Epidural Morphine for Analgesia Following Stifle Arthrotomy in Dogs

We prospectively studied 18 dogs that presented for exploratory stifle arthrotomy, with or without meniscectomy, and lateral extracapsular stabilization as a result of cranial cruciate ligament rupture. Dogs were premedicated with acepromazine, induced with thiopental, and maintained with halothane in oxygen. Preoperatively, dogs were assigned to one of three groups. Group 1 (n = 6) received intra-articular morphine (0.1 mg/kg diluted in 1 mL/10 kg body weight of saline) and epidural saline (1 mL/5 kg body weight saline plus the volume of saline representing 0.1 mg/kg of morphine). Group 2 (n = 6) received intra-articular saline (1 mL/10 kg body weight of saline plus the volume of saline representing 0.1 mg/kg of morphine) and epidural saline (1 mL/5 kg body weight saline plus the volume of saline representing 0.1 mg/kg of morphine). Group 3 (n = 6) received intra-articular saline (1 mL/10 kg body weight of saline plus the volume of saline representing 0.1 mg/kg of morphine) and epidural morphine (0.1 mg/kg of morphine diluted in 1 mL/5 kg body weight saline). The efficacy of each analgesia regimen was evaluated for 6 hours postoperatively with a pain score based on subjective and objective variables. Serum Cortisol and blood glucose concentrations were measured. Butorphanol was used to provide analgesia as needed based on a predetermined maximum pain score. Supplemental analgesics were required postoperatively every 2 to 3 hours for 6 hours in all dogs that did not initially receive analgesics (group 2). Pain scores were significantly lower in dogs administered morphine intra-articularly (group 1) and epidurally (group 3) at 30 minutes and 30, 120, and 360 minutes, respectively, compared with dogs that did not initially receive analgesics (group 2). One dog in group 1 and one dog in group 3 required supplemental analgesia with butorphanol. There was no difference between analgesia produced by intra-articular morphine compared with that of epidural morphine. Side effects after intra-articular or epidural morphine were not observed. Intra-articular administration of morphine can produce effective analgesia in dogs comparable with that produced by epidural administration of morphine.     

Epidural Morphine in Goats after Hindlimb Orthopedic Surgery

Morphine (0.1 mg/kg) diluted with 0.9% saline to a volume of 0.13 mL/kg was administered into the epidural space at the lumbosacral junction in 10 halothane-anesthetized goats immediately before discontinuation of halothane. The same volume of 0.9% saline was given to control group of eight anesthetized goats. Both groups had undergone an orthopedic procedure that replaced the anterior cruciate ligament with a patellar tendon autograft. The appearance and unprovoked behavior of goats in the morphine group were significantly different (p < .05) from the saline groups. The goats in the morphine group were more sedate and struggled less during recovery. Epidural morphine did not produce respiratory depression or bloat during a 9 hour observation period. Heart rate, respiratory rate, and blood pressure (mean, systolic, and diastolic) of the morphine group did not differ from those of the control group.     

Effect of intravenous administration of furosemide on mass-specific maximal oxygen consumption and breathing mechanics in exercising horses

OBJECTIVES: To determine whether i.v. administration of furosemide (250 mg) to horses before maximal exercise affected maximal oxygen consumption (VO2max), breathing mechanics, or gas exchange during exercise. ANIMALS: 7 healthy, well-conditioned Thoroughbred horses. PROCEDURES: 5 horses initially performed an incremental treadmill exercise test to determine VO2max 4 hours after i.v. administration of furosemide (250 mg i.v.) or placebo (saline [0.9% NaCl] solution). Time to fatigue and distance run were recorded. All 7 horses were then used to determine the effects of furosemide on gas exchange and breathing mechanics at 40, 60, 80, and 100% of VO2max. Horses were weighed immediately before exercise. RESULTS: Furosemide treatment significantly increased mass-specific VO2max (5.3%), but absolute VO2max was not significantly altered. In the 2 parts of the study, body weights were 2.9 and 2.5% higher when horses were given placebo than when they were given furosemide. Time and distance run at speeds > or = 11.0 m/s were significantly greater following furosemide administration. Furosemide treatment had no effect on breathing mechanics or gas exchange. CONCLUSIONS AND CLINICAL RELEVANCE: Previous studies have suggested that prerace administration of furosemide may have a positive effect on performance. Results of this study indicate that this may be attributable, in part, to an increase in mass-specific VO2max but not to improvements in breathing mechanics or gas exchange. Most of the increase in mass-specific VO2max appeared to be attributable to weight loss associated with diuresis induced by furosemide.     

Effects of epidurally administered morphine or buprenorphine on the thermal threshold in cats

Objective: To determine the antinociceptive effects of epidural administration of morphine or buprenorphine in cats by use of a thermal threshold model. ANIMALS: 6 healthy adult cats. PROCEDURES: Baseline thermal threshold was determined in duplicate. Cats were anesthetized with isoflurane in oxygen. Morphine (100 microg/kg diluted with saline [0.9% NaCl] solution to a total volume of 0.3 mL/kg), buprenorphine (12.5 microg/kg diluted with saline solution to a total volume of 0.3 mL/kg), or saline solution (0.3 mL/kg) was administered into the epidural space according to a Latin square design. Thermal threshold was determined at various times up to 24 hours after epidural injection. RESULTS: Epidural administration of saline solution did not affect thermal threshold. Thermal threshold was significantly higher after epidural administration of morphine and buprenorphine, compared with the effect of saline solution, from 1 to 16 hours and 1 to 10 hours, respectively. Maximum (cutout) temperature was reached without the cat reacting in 0, 74, and 11 occasions in the saline solution, morphine, and buprenorphine groups, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Epidural administration of morphine and buprenorphine induced thermal antinociception in cats. At the doses used in this study, the effect of morphine lasted longer and was more intense than that of buprenorphine.     

Use of a von Frey device for evaluation of pharmacokinetics and pharmacodynamics of morphine after intravenous administration as an infusion or multiple doses in dogs

OBJECTIVE: To evaluate the pharmacokinetics and pharmacodynamics of morphine after IV administration as an infusion or multiple doses in dogs by use of a von Frey (vF) device. ANIMALS: 6 dogs. PROCEDURE: In the first 2 crossover experiments of a 3-way crossover study, morphine or saline (0.9%) solution was administered via IV infusion. Loading doses and infusion rates were administered to attain targeted plasma concentrations of 10, 20, 30, and 40 ng/mL. In the third experiment, morphine (0.5 mg/kg) was administered IV every 2 hours for 3 doses. The vF thresholds were measured hourly for 8 hours. Plasma concentrations of morphine were measured by high-pressure liquid chromatography. RESULTS: No significant changes in vF thresholds were observed during infusion of saline solution. The vF thresholds were significantly increased from 5 to 8 hours during the infusion phase, corresponding to targeted morphine plasma concentrations > 30 ng/mL and infusion rates > or = 0.15 +/- 0.02 mg/kg/h.The maximal effect (EMAX) was 78 +/- 11% (percentage change from baseline), and the effective concentration to attain a 50% maximal response (EC50) was 29.5 +/- 5.4 ng/mL. The vF thresholds were significantly increased from 1 to 7 hours during the multiple-dose phase; the EC50 and EMAX were 23.9 +/- 4.7 ng/mL and 173 +/- 58%, respectively. No significant differences in half-life, volume of distribution, or clearance between the first and last dose of morphine were detected. CONCLUSIONS AND CLINICAL RELEVANCE: Morphine administered via IV infusion (0.15 +/- 0.02 mg/kg/h) and multiple doses (0.5 mg/kg, IV, every 2 hours for 3 doses) maintained significant antinociception in dogs.     

Evaluation of safety and pharmacokinetics of vancomycin after intravenous regional limb perfusion in horses

OBJECTIVE: To evaluate clinical variables, regional concentrations, and pharmacokinetics of vancomycin in the synovial fluid of distal forelimb joints of horses after IV regional limb perfusion. ANIMALS: 6 horses. PROCEDURE: Vancomycin was administered via IV regional limb perfusion to the distal portion of the forelimbs of anesthetized horses. Drug (300 mg of vancomycin hydrochloride in 60 mL of saline [0.9% NaCl] solution) was infused into 1 forelimb, whereas the contralateral limb served as a control and was perfused with 60 mL of saline solution. Solutions were injected into the lateral digital vein after digital exsanguination. Synovial fluid from the metacarpophalangeal (MTCP) and distal interphalangeal (DIP) joints and systemic blood were collected prior to perfusion and 15, 30, 45, 65, and 90 minutes after initiation of the infusion. Synovial fluid from the MTCP joint and blood were also obtained at 4, 8, 12, and 24 hours after infusion. Plasma urea and creatinine concentrations, degree of lameness, and certain clinical variables involving the MTCP joint and infusion site were assessed for 7 days. Results were compared between the vancomycin treatment and control groups. RESULTS: No complications or significant differences in renal function, lameness, or clinical variables were observed between groups. Vancomycin concentrations exceeded 4 microg/mL in MTCP joints for approximately 20 hours. Higher concentrations were reached in DIP joints than in MTCP joints. CONCLUSIONS AND CLINICAL RELEVANCE: IV regional limb perfusion with 300 mg of vancomycin as a 0.5% solution was safe and may be useful in horses as treatment for distal limb infections.     

Intratracheal clenbuterol in the horse: its pharmacological efficacy and analytical detection

Clenbuterol, a beta2 agonist/antagonist, is the only bronchodilator approved by the US Food and Drug Administration for use in horses. The Association of Racing Commissioners International classifies clenbuterol as a class 3 agent, and, as such, its identification in post-race samples may lead to sanctions. Anecdotal reports suggest that clenbuterol may have been administered by intratracheal (IT) injection to obtain beneficial effects and avoid post-race detection. The objectives of this study were (1) to measure the pharmacological efficacy of IT dose of clenbuterol and (2) to determine the analytical findings in urine in the presence and absence of furosemide. When administered intratracheally (90 microg/horse) to horses suffering from chronic obstructive pulmonary disease (COPD), clenbuterol had effects that were not significantly different from those of saline. In parallel experiments using a behavior chamber, no significant effects of IT clenbuterol on heart rate or spontaneous locomotor activity were observed. Clenbuterol concentrations in the urine were also measured after IT dose in the presence and absence of furosemide. Four horses were administered i.v. furosemide (5 mg/kg), and four horses were administered saline (5 mL). Two hours later, all horses were administrated clenbuterol (IT, 90 microg), and the furosemide-treated horses received a second dose of furosemide (2.5 mg/kg, i.v.). Three hours after clenbuterol dose (1 h after hypothetical 'post-time'), the mean specific gravity of urine samples from furosemide-treated horses was 1.024, well above the 1.010 concentration at which furosemide is considered to interfere with drug detection. There was no interference by furosemide with 'enhanced' ELISA screening of clenbuterol equivalents in extracted and concentrated samples. Similarly, furosemide had no effect on mass spectral identification or quantification of clenbuterol in these samples. These results suggest that the IT dose of clenbuterol (90 microg) is, in pharmacological terms, indistinguishable from the dose of saline, and that, using extracted samples, clenbuterol dose is readily detectable at 3 h after dosing. Furthermore, concomitant dose of furosemide does not interfere with detection or confirmation of clenbuterol.     

Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects

Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.     

Effect of caudal epidural xylazine on intraoperative distress and post-operative pain in Holstein heifers

Objective To compare the effects of caudal epidural xylazine versus saline on tolerance of paravertebral nerve block and flank surgery and on post‐operative pain in heifers used for a veterinary student training laboratory. Study design Randomized controlled prospective study. Animals Fourteen one‐year‐old, nongravid, healthy Holstein heifers, weighing 360 ± 5 kg. Methods Xylazine (0.05 mg kg^?1) or 0.9% saline (5 mL) was injected using a caudal epidural technique to seven heifers undergoing a flank surgery. Nerve block of the right paravertebral fossa was performed using equal parts of lidocaine 2% and bupivacaine 0.5%. Heart and respiratory rates, rectal temperature, rumination frequency, and appetite were recorded before and at 4, 8, and 24 hours after surgery. Scores were recorded for: tolerance of local anesthesia injections (pre‐operatively), sedation, ataxia and distress (intraoperatively, every 30 minutes), and pain (4, 8, and 24 hours post‐operatively). Results The animals reaction to local anesthetic injection was judged to be less in the xylazine group by both an experienced observer (p < 0.001) and student surgeons (p < 0.01). The xylazine group required less local anesthetic (82.9 ± 13.8 mL) versus the saline group (108.4 ± 19.6 mL, p = 0.035). Intraoperatively, xylazine heifers were more sedated at all times (p‐values from <0.001 to 0.017), were more ataxic for the first 1.5 hours (p‐values from <0.001 to 0.026), and lower in distress at all times (p‐values from <0.001 to 0.007). No difference in post‐operative pain or physiologic variables was found, except immediately post‐operatively, rectal temperature was higher in the xylazine group (39.5 ± 0.3 °C) than in the saline group (38.6 ± 0.2 °C, p < 0.001). Conclusion and clinical relevance Compared with epidural saline, caudal epidural xylazine reduced distress of anesthetic injection and surgical manipulation in heifers and an improvement in animal well‐being was apparent. This effect may have been as a result of sedation. Pre‐operative epidural xylazine did not appear to improve post‐surgical analgesia in our study.     

Prostaglandin F2 alpha and prolactin in experimental hypogalactia in sows

Peripheral plasma concentrations of 13,14-dihydro-15-keto-prostaglandin F2alpha(PGFM), progesterone, prolactin and oestrone were determined in 20 sows for two days before and three weeks after parturition. Groups of four sows each received one of the following five treatments post partum: 30 ml sterile 0.9 per cent saline solution intrauterinely; ovariectomy and 30 ml saline solution intrauterinely; 10 ml Lugol's iodine plus 20 ml saline solution intrauterinely; ovariectomy and 10 ml Lugol's iodine plus 20 ml saline solution intrauterinely, or progesterone (0.5 mg [kg bodyweight]-1 intramuscularly). Saline solution and iodine were administered every 48 hours, starting immediately after parturition, for one week. Ovariectomy was performed within eight hours of delivery. Progesterone was given every third day for 12 days. Piglet weight gains were used as a reflection of milk yield. In all sows, oestrone values were elevated before parturition, but fell by the end of delivery and were very low during lactation. PGFM concentrations rose during the last two days of pregnancy to reach maximal values at the time of delivery. Plasma progesterone levels declined concomitantly with the rise in PGFM values before parturition. Basal values of progesterone were achieved within 24 hours after delivery in control sows receiving saline treatment. Progesterone values fell immediately after ovariectomy in sows receiving saline or iodine treatment but were slightly elevated for one week in sows that received only intrauterine iodine treatment, suggesting that complete regression of corpora lutea is prevented by suppression of post parturient uterine prostaglandin production. Sows injected with progesterone maintained plasma values of about 5 to 15 nmol litre-1.(ABSTRACT TRUNCATED AT 250 WORDS)     

高效液相色谱法检测中兽药散剂中的氟苯尼考

建立了检测止痢散、白头翁散、苍术香连散等三种中兽药散剂中违规添加氟苯尼考的高效液相色谱法。根据氟苯尼考临床预防、治疗用量和中兽药散剂临床用量,在散剂中定量添加氟苯尼考作为阳性样品。样品经乙腈提取、流动相（乙腈-水）稀释,高效液相色谱-二极管阵列检测器测定氟苯尼考含量。结果显示,在10～500μg/mL浓度范围内线性关系良好;添加回收率在95%～101%之间,变异系数小于1.4%,检测限均为50 mg/kg。该方法快速、准确,可用于上述三种中兽药散剂中违规添加氟苯尼考的定量测定。     

Activity of amphotericin B in lipid emulsion in the initial treatment of canine leishmaniasis

Amphotericin B was given to 19 dogs with leishmaniasis. The drug was diluted in an emulsion prepared by mixing 50 mg of amphotericin B desoxycholate with 40 ml of sterile water and 10 ml of soya bean oil solution. The dogs were infused over nearly one hour with 50 ml/kg of normal saline followed by 10 ml/kg of mannitol 20 per cent. The mixture was then loaded over 30 to 60 minutes using a syringe pump. The emulsion was given twice weekly, at an increasing dosage (from 1 to 2.5 mg/kg bodyweight), for a minimum of eight injections. All 17 dogs receiving a total dosage of more than 10 mg/kg were clinically cured by the end of the treatment, and 14 of these had a negative polymerase chain reaction test on bone marrow.     

Evaluation of the effect of ranitidine on gastroduodenal contractile activity and gastric emptying in horses

Objective-To determine the effect of ranitidine on gastric emptying in horses. Animals-11 adult horses. Procedures-In vitro, isolated muscle strips from the pyloric antrum and duodenum of 5 horses were suspended in baths and attached to isometric force transducers. Once stable spontaneous contractions were observed, ranitidine or diluent was added at cumulative increasing concentrations. Isometric stress responses were compared. In vivo, 6 horses were assigned to a group in a prospective randomized crossover study design with a wash-out period of 2 weeks between trials. Ranitidine (2.2 mg/kg) or saline (0.9% NaCl) solution was administered IV, and 15 minutes later, acetaminophen (20 mg/kg), diluted in 400 mL of water, was administered via nasogastric tube to evaluate the liquid phase of gastric emptying. Serum acetaminophen concentration was measured at several time points for 3 hours by use of liquid chromatography tandem mass spectrometry. Frequency of defecation was recorded during the 3 hours of the study. Results-Ranitidine increased the contractile activity of the pyloric antrum smooth muscle at a concentration of 10(4) M. No significant effect of ranitidine on plasma kinetics of acetaminophen was identified. Frequency of defecation did not differ between groups. Conclusions and Clinical Relevance-Ranitidine did increase gastric motility in vitro, but no effect on liquid phase gastric emptying was identified in healthy horses by use of the acetaminophen absorption model. Results do not support the use of ranitidine to promote gastric emptying.     

Effects of an intravenous endotoxin challenge on glucose and insulin dynamics in horses

OBJECTIVE: To evaluate the effects of endotoxin administered IV on glucose and insulin dynamics in horses. ANIMALS: 16 healthy adult mares. PROCEDURES: Each week of a 2-week randomized crossover study, each horse received an IV injection (duration, 30 minutes) of Escherichia coli O55:B5 lipopolysaccharide (LPS) in 60 mL of sterile saline (0.9% NaCl) solution (20 ng/kg) or sterile saline solution alone (control treatment). Frequently sampled IV glucose tolerance test procedures were performed at 24 hours before (baseline) and 24 and 48 hours after injection; glucose and insulin dynamics were assessed via minimal model analysis. RESULTS: 13 of 16 horses had a clinical response to LPS, which was characterized by mild colic and leukopenia. Before treatment, mean +/- SD insulin sensitivity was 2.9 +/- 1.9 x 10(4) L x min(1) x mU(1); this significantly decreased to 0.9 +/- 0.9 x 10(4) L x min(1) x mU(1) 24 hours after treatment (69% reduction) and was 1.5 +/- 0.9 x 10(4) L x min(1) x mU(1) 48 hours after treatment. At baseline, mean +/- SD acute insulin response to glucose was 520 +/- 196 mU x min x L(1); this significantly increased to 938 +/- 620 mU x min x L(1) (80% increase) and 755 +/- 400 mU x min x L(1) (45% increase) at 24 and 48 hours after LPS treatment, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Compared with baseline values, insulin sensitivity was decreased for 24 hours after IV injection of LPS, and affected horses had a compensatory pancreatic response. These disturbances in glucose and insulin dynamics may contribute to development of laminitis in horses.     

Pharmacokinetics after oral and intravenous administration of a single dose of tramadol hydrochloride to Hispaniolan Amazon parrots (Amazona ventralis)

Objective-To determine pharmacokinetics after IV and oral administration of a single dose of tramadol hydrochloride to Hispaniolan Amazon parrots (Amazona ventralis). Animals-9 healthy adult Hispaniolan Amazon parrots (3 males, 5 females, and 1 of unknown sex). Procedures-Tramadol (5 mg/kg, IV) was administered to the parrots. Blood samples were collected from -5 to 720 minutes after administration. After a 3-week washout period, tramadol (10 and 30 mg/kg) was orally administered to parrots. Blood samples were collected from -5 to 1,440 minutes after administration. Three formulations of oral suspension (crushed tablets in a commercially available suspension agent, crushed tablets in sterile water, and chemical-grade powder in sterile water) were evaluated. Plasma concentrations of tramadol and its major metabolites were measured via high-performance liquid chromatography. Results-Mean plasma tramadol concentrations were > 100 ng/mL for approximately 2 to 4 hours after IV administration of tramadol. Plasma concentrations after oral administration of tramadol at a dose of 10 mg/kg were < 40 ng/mL for the entire time period, but oral administration at a dose of 30 mg/kg resulted in mean plasma concentrations > 100 ng/mL for approximately 6 hours after administration. Oral administration of the suspension consisting of the chemical-grade powder resulted in higher plasma tramadol concentrations than concentrations obtained after oral administration of the other 2 formulations; however, concentrations differed significantly only at 120 and 240 minutes after administration. Conclusions and Clinical Relevance-Oral administration of tramadol at a dose of 30 mg/kg resulted in plasma concentrations (> 100 ng/mL) that have been associated with analgesia in Hispaniolan Amazon parrots.     

Effects of ketamine, diazepam, and their combination on intraocular pressures in clinically normal dogs

OBJECTIVE: To evaluate the effects of ketamine, diazepam, and the combination of ketamine and diazepam on intraocular pressures (IOPs) in clinically normal dogs in which premedication was not administered. ANIMALS: 50 dogs. PROCEDURES: Dogs were randomly allocated to 1 of 5 groups. Dogs received ketamine alone (5 mg/kg [KET5] or 10 mg/kg [KET10], IV), ketamine (10 mg/kg) with diazepam (0.5 mg/kg, IV; KETVAL), diazepam alone (0.5 mg/kg, IV; VAL), or saline (0.9% NaCl) solution (0.1 mL/kg, IV; SAL). Intraocular pressures were measured immediately before and after injection and at 5, 10, 15, and 20 minutes after injection. RESULTS: IOP was increased over baseline values immediately after injection and at 5 and 10 minutes in the KET5 group and immediately after injection in the KETVAL group. Compared with the SAL group, the mean change in IOP was greater immediately after injection and at 5 and 10 minutes in the KET5 group. The mean IOP increased to 5.7, 3.2, 3.1, 0.8, and 0.8 mm Hg over mean baseline values in the KET5, KET10, KETVAL, SAL, and VAL groups, respectively. All dogs in the KET5 and most dogs in the KETVAL and KET10 groups had an overall increase in IOP over baseline values. CONCLUSIONS AND CLINICAL RELEVANCE: Compared with baseline values and values obtained from dogs in the SAL group, ketamine administered at a dose of 5 mg/kg, IV, caused a significant and clinically important increase in IOP in dogs in which premedication was not administered. Ketamine should not be used in dogs with corneal trauma or glaucoma or in those undergoing intraocular surgery.