Clinical effects of epidurally administered ketamine and xylazine in goats

The Prevalence of Xylazine in Patient Urine Samples That Were Positive for Fentanyl in Western New York

BACKGROUND

Xylazine, a veterinary sedative, is increasingly being discovered in the illegal drug supply across the United States and is associated with overdose fatalities. Not approved for human use, xylazine poses life-threatening risks, particularly when used in conjunction with opioids such as fentanyl. This study evaluates the prevalence of xylazine in urine samples that screened positive for fentanyl. The evaluation involved measuring the parent drug xylazine and its metabolites, xylazine glucuronide and hydroxy-xylazine, as well as finding their correlation with fentanyl and norfentanyl concentrations in patient samples.

METHODS

Samples were collected over a one-month period. Urine samples were analyzed for fentanyl, norfentanyl, and 3 xylazine-specific analytes (i.e., xylazine, xylazine glucuronide, and hydroxy-xylazine). Briefly, reverse-phase chromatographic separation was performed on a Bonshell Phenyl-Hexyl column utilizing a binary mobile phase gradient. The eluents were detected through positive electrospray ionization and multiple reaction monitoring analysis on a triple quadrupole mass spectrometer.

RESULTS

Out of a total of 230 urine samples, 184 were confirmed positive for fentanyl. Xylazine was detected in 56 out of the 184 fentanyl-positive samples, accounting for 30% of the fentanyl-positive confirmatory test. Xylazine (or its metabolites) was not observed in fentanyl-negative samples. Furthermore, the parent xylazine drug was detected in all 56 samples, whereas the metabolite glucuronide and hydroxy forms were only detected in 28 and 6 samples, respectively.

CONCLUSIONS

This study estimated a xylazine prevalence of 30% in fentanyl-positive urine samples within our local Western New York population. This study represents the first report within our clinical population.

Balanced anesthesia in pigeons (Columba livia): a protocol that ensures stable vital parameters and feasibility during long surgeries in cognitive neuroscience

In neuroscience, numerous experimental procedures in animal models require surgical interventions, such as the implantation of recording electrodes or cannulas before main experiments. These surgeries can take several hours and should rely on principles that are common in the field of research and medicine. Considering the characteristics of the avian respiratory physiology, the development of a safe and replicable protocol for birds is necessary to minimize side effects of anesthetic agents, circumvent technical limitations due to the insufficient availability of patient monitoring, and to maintain stable intraoperative anesthesia. Through the consistent and responsible implementation of the three R principle of animal welfare in science ("Replace, Reduce, Refine"), we aimed to optimize experimental methods to minimize the burden on pigeons (Columba livia) during surgical procedures. Here, surgeries were conducted under balanced anesthesia and perioperative monitoring of heart rate, oxygen saturation, body temperature, and the reflex state. The protocol we developed is based on the combination of injectable and inhalative anesthetic drugs [ketamine, xylazine, and isoflurane, supported by the application of an opiate for analgesia (e.g., butorphanol, buprenorphine)]. The combination of ketamine and xylazine with a pain killer is established in veterinary medicine across a vast variety of species. Practicability was verified by survival of the animals, fast and smooth recovery quantified by clinical examination, sufficiency, and stability of anesthesia. Independent of painful stimuli like incision or drilling, or duration of surgery, vital parameters were within known physiological ranges for pigeons. Our approach provides a safe and conservative protocol for surgeries of extended duration for scientific applications as well as for veterinary medicine in pigeons which can be adapted to other bird species.

Comparative evaluation of sedative and anti-nociceptive effects of epidural romifidine, romifidine-lidocaine, and lidocaine in donkeys (Equus asinus)

Background

Local and regional anesthetic procedures are valuable tools in veterinary practice. Caudal epidural administration of local anesthetic agents is widely reported for surgical interventions of the tail, anus, rectum, vulva, vagina, urethra, and bladder in the standing horse. Epidural analgesia is also obtained using various drugs such as alpha-2 adrenoceptor agonists, dissociative anesthetics, and opioids. The present study evaluates the anti-nociceptive and sedative effects of epidural administration of romifidine, a romifidine-lidocaine combination, and lidocaine alone in donkeys.

Materials and methods

In a randomized prospective study, twenty-four healthy adult donkeys were assigned to four groups (three experimental and one control; n = 6) received either 50 μg/kg of romifidine, 0.30 mg/kg of lidocaine, combined romifidine (50 μg/kg) and lidocaine (0.30 mg/kg) diluted in 0.9% sterile normal saline solution to a total injection volume of 12 ml, or an equivalent volume of sterile saline epidurally. After epidural injection of each treatment, the onset, degree, and duration of sedation and anatomical extension of anti-nociception were documented. Observations began immediately (time 0) pre-administration and at 5, 15, 30, 45, 60, and 30-min intervals subsequently until 210 min after drug injection. Time to onset of perineal analgesia was documented every minute after the epidural injection by evaluating the animal's response to pinpricks.

Results

Only romifidine and romifidine-lidocaine induced mild to moderate sedation. Romifidine, romifidine-lidocaine, and lidocaine induced complete bilateral caudal epidural analgesia with loss of sensation in the perineum, tail, inguinal region, caudal aspect of the upper hind limb, chest areas, and extended distally to the dorsal metatarsal area. Sedation lasted longer (p < 0.05) with romifidine (160 ± 15.4 min) than with romifidine-lidocaine (141.6 ± 13.2 min). Longer-lasting analgesia (p < 0.05) was obtained with romifidine (158.3 ± 9.8 min) and romifidine-lidocaine (165 ± 9.4 min) than with lidocaine (75.8 ± 8 min).

Conclusions

Epidural administration of a single dose of romifidine or a combination of romifidine-lidocaine produced mild to moderate sedation and complete anti-nociception in the perineal and inguinal regions of donkeys. The clinical usefulness of epidural romifidine or romifidine-lidocaine combinations to perform obstetric procedures in donkeys needs to be assessed.

Intrathecal adenosine enhances the antinociception of Xylazine in goats

Background

The role of adenosine (AD) in neuromodulation of nociceptive signaling at the level of the spinal cord has been established in both preclinical and clinical models. Recently, the signaling pathway that involves adenosine 5-monophosphate activated protein kinase has been reported to mediate the antinociceptive effects of xylazine (XYL). The objective of this study was to investigate the antinociceptive, cardiorespiratory and hematological effects of intrathecal administration of combined XYL-AD in goats as compared to XYL alone. Six clinically healthy adult goats weighing 25 ± 2 kg were randomly assigned to one of three groups in a cross-over design. Goats were sedated with XYL (0.05 mg/kg, IM) in all groups. Ten min later, 0.9% saline solution [SAL group], XYL (0.05 mg/kg) [XYL group] or a combination of XYL (0.05 mg/kg) and AD (2000 µg) [XYL-AD group] was injected intrathecally. Antinociception scores and both cardiorespiratory and hematological parameters were measured before XYL sedation and intrathecal injection (baseline), and at 5, 10, 15, 30, 60, 90, 120 and 150 min thereafter.

Results

The XYL-AD group showed significantly earlier onset of antinociception [5 (5–7) min] than XYL [13 (12–14.25] min (P = 0.031). The duration of complete antinociception in goats that received XYL-AD was significantly longer (P = 0.031) than that received XYL alone [65 (58.75–66.25) and 47.5 (43.75–51.25) min, respectively]. In both XYL and XYL-AD groups, heart rate (HR), arterial blood pressure (SAP, MAP and DAP) were significantly decreased (P < 0.05) compared to the baseline. Compared to the SAL group, a statistically significant reduction in HR from 10 to 150 min (P < 0.05) was detected in the XYL group contrary to the XYL-AD group. Differences in the hematological parameters among different groups were insignificant.

Conclusions

AD injected intrathecally interacts synergistically with XYL to promote antinociception in goats. This discovery supports the use of AD in combination with XYL in clinical trials.

Subarachnoid ketamine and ketamine s (+) associated with lidocaine in sheep and goats anesthesia

Ten male sheep (Sheep group; SGk) and seven male goats (Goat group; GGks+) were used in this study. The objective was to compare the use of racemic ketamine or ketamine S(+) associated with lidocaine on spinal anesthesia and evaluate if the drugs leads to a surgical anesthesia state, as well as to verify the cardiorespiratory, sedative and motor effects of this technique in these species. After correct placement of the needle in the subarachnoid space, 3.0 mg kg-1 of racemic ketamine (SGk) or ketamine S(+) (GGks+), both diluted in 1.5 mg kg-1 of 2% lidocaine, were administered. Evaluations were performed during orchiectomy, at times 0 (T0), 5 (T5), 10 (T10), 20 (T20), 30 (T30) and 60 (T60) minutes after subarachnoid anesthesia administration. No significant changes in heart and respiratory rates were observed in both experimental groups. All animals showed surgical analgesia and stood conscious or slightly sedated with ataxia immediately after the drugs administration (T5), allowing the execution of bilateral orchiectomy. The ataxia in SGk was classified as severe with recumbency in 80% of the animals, moderate ataxia in 10% of the animals, and mild ataxia in 10% of the animals. All goats (GGks+; 100%) presented severe ataxia and recumbency. At 60 min, animals of both groups were in standing position and with normal gait. Subarachnoid RS-ketamine and ketamine S(+) (3 mg kg-1), associated with lidocaine in sheep and goats, produces surgical anesthesia and recumbency without causing cardiorespiratory abnormalities, regurgitation and bloating.

Assessment of a multimodal analgesia protocol in goats undergoing claw amputation

Objective: To evaluate the anti-nociceptive, sedative and behavioral effect of multimodal analgesic drugs in goat's undergoing unilateral claw amputation. Design: A randomized experimental design. Animals: Sixteen goats were randomly assigned into 4 groups (4 bucks per group). Procedure: Animals used in this study were randomly assigned into 4 groups, four animals for each group. All goats were anaesthetized by intravenous regional anesthesia (IVRA) of the right forelimb cephalic vein with 2% lidocaine in a dose of 3mg/kg body weight (BW) before surgery. Administration of carprofen (50 mg/ml) at a dose 0.1 mg/kg BW took place before surgery on day 0 and was then repeated once daily for another 3 consecutive days postoperatively in groups Lidocaine (L), carprofen_lidocaine (CL), carprofen – romifidine - lidocaine (CRL), and carprofen – romifidine - butorphenol - lidocaine (CRBL). Heart rate (HR), respiratory rate (RR), rectal temperature (RT), serum IL-6 level, sedation score, and lameness score were determined at preset time intervals and the animals’ behavior was recorded. Results: The mean average of HR, RR and RT in IVRA treated animals was significantly increased until the end of surgery followed by gradual decrease up to 90 min post-surgery. In CRL and CRBL it showed a significant decrease compared to controls. There was a significant decrease in lameness score in CRL and CRBL treated animals from 30 min until 2 hours and for 3 days post-surgery. After injection of romifidine it showed a significant decrease of IL-6 levels compared to lidocaine and CL treated animals. Conclusion and clinical relevance: It was concluded that, the use of romifidine and buterphanol in the analgesic protocol during claw amputation in goats, alleviate pain response and potentiate the analgesic effects of IVRA. Addition of carprofen to the analgesic protocol can be used for long- term treatment of orthopedic pain in goats without complications.

Ultrasound-guided block of sciatic and femoral nerves: an anatomical study

The sheep is a popular animal model for human biomechanical research involving invasive surgery on the hind limb. These painful procedures can only be ethically justified with the application of adequate analgesia protocols. Regional anaesthesia as an adjunct to general anaesthesia may markedly improve well-being of these experimental animals during the postoperative period due to a higher analgesic efficacy when compared with systemic drugs, and may therefore reduce stress and consequently the severity of such studies. As a first step 14 sheep cadavers were used to establish a new technique for the peripheral blockade of the sciatic and the femoral nerves under sonographic guidance and to evaluate the success rate by determination of the colorization of both nerves after an injection of 0.5 mL of a 0.1% methylene blue solution. First, both nerves were visualized sonographically. Then, methylene blue solution was injected and subsequently the length of colorization was measured by gross anatomical dissection of the target nerves. Twenty-four sciatic nerves were identified sonographically in 12 out of 13 cadavers. In one animal, the nerve could not be ascertained unequivocally and, consequently, nerve colorization failed. Twenty femoral nerves were located by ultrasound in 10 out of 13 cadavers. In three cadavers, signs of autolysis impeded the scan. This study provides a detailed anatomical description of the localization of the sciatic and the femoral nerves and presents an effective and safe yet simple and rapid technique for performing peripheral nerve blocks with a high success rate.

Assessment of Common Anaesthetic and Clinical Indices of Multimodal Therapy of Propofol, Xylazine, and Ketamine in Total Intravenous Anaesthesia in West African Dwarf Goat

The assessment of anaesthetic and clinical indices of multimodal therapy of propofol, xylazine, and ketamine was done in West African Dwarf (WAD) goat. Sixteen healthy male WAD goats were assigned into four treatment groups, namely, control (group A) (ketamine 5 mg/kg + xylazine 0.05 mg/kg), group B (propofol 5 mg/kg + xylazine 0.05 mg/kg), group C (propofol 5 mg/kg + ketamine 5 mg/kg), and group D (propofol 2.5 mg/kg + ketamine 2.5 mg/kg + xylazine 0.05 mg/kg). All drugs were administered intravenously. The multimodal therapy decreased significantly (P < 0.05) the heart rate in groups A, B, and D. Also respiratory rate significantly (P < 0.05) decreased in groups A, B, and D but significantly (P < 0.05) increased at 20 min after induction in group C. However, temperature significantly (P < 0.05) decreased in groups A, B, and C. The induction was good and smooth in groups B and D. Surgical anaesthetic time was longer in groups B and D and shorter in group C. The quality of recovery was good in groups B and D. Side effects such as salivation and apnoea were observed in all groups. In conclusion, the multimodal therapy could be used successfully. However, group D could be the best combination considering the parameters measured.

Anesthesia and analgesia in sheep and goats

Physical or chemical restraint, with or without local anesthesia, has been extensively used to perform diagnostic or minor surgical procedures in small ruminants. However, anesthetic and analgesic techniques are required when specific diagnostic procedures and painful surgery are to be performed. Apart from improving animal welfare standards, anesthesia and analgesia are essential to make the procedures easier and improve both animal and personnel safety. This article provides an overview of the anesthetic and analgesic agents and techniques commonly used in sheep and goats.

Clinicophysiological Effects of Spinally Administered Ketamine and Its Combination with Xylazine and Medetomidine in Healthy Goats

The study was conducted in 9 healthy adult goats of either sex, weighing 15-20 kg, to evaluate and compare the clinicophysiological effects of spinally administered ketamine alone and in combination with xylazine and medetomidine. Nine trials each of the three treatments were conducted randomly by injecting ketamine (2.5 mg/kg) (n = 9), ketamine and xylazine (2.5 mg/kg and 0.05 mg/kg) (n = 9) and ketamine and medetomidine (2.5 mg/kg and 10 microg/kg) (n = 9). The drugs were administered at the lumbosacral subarachnoid space under strict aseptic conditions. The treatments were evaluated on the basis of clinicophysiological, haematological, biochemical and haemodynamic observations. Ketamine produced mild to moderate analgesia of the hindquarters. Its combination with either xylazine or medetomidine produced complete analgesia of the hindquarters for 45-60 min. Ataxia was moderate in the ketamine group, whereas animals attained sternal recumbency in the combination groups. A moderate degree of sedation was recorded in the combination groups. Heart rate and respiratory rate depression in the combination groups and heart rate and respiratory rate stimulation in ketamine group were recorded. Haematological parameters decreased in all the groups. Increase in serum glucose, creatinine and urea nitrogen was recorded in all the groups. Serum electrolytes did not show any significant change. The results showed that the combination of ketamine with xylazine or medetomidine at these dose rates produced a comparable degrees of analgesia of hindquarters with transient and minimal cardiopulmonary side effects.

Effects of epidural ketamine-xylazine combination on the clinicophysiological and haematobiochemical parameters of uraemic and healthy goats

Xylazine-ketamine combination was evaluated for its efficacy and safety after epidural administration in uraemic and healthy goats. The combination (xylazine 0.025 mg/kg and ketamine 2.5 mg/kg) was administered to uraemic (n = 6) and healthy (n = 6) animals in the lumbosacral epidural space. The combination was evaluated in terms of clinical, physiological, haematological and biochemical parameters. The onset of analgesia was faster in healthy animals than in uraemic animals. Xylazine and ketamine produced complete analgesia of tail, perineum, inguinal and thigh regions in all animals of both groups. However, healthy animals showed longer duration of complete analgesia than did uraemic animals. Greater ataxia was recorded in healthy animals than in uraemic animals. The heart rate showed a significant decrease in both groups; however, respiratory rate and rectal temperature did not show any significant changes. Haemoglobin, packed cell volume and total leukocyte count decreased non-significantly in both groups. Total leukocyte count was significantly higher in uraemic animals. A significantly higher value of urea nitrogen and creatinine was recorded in uraemic animals. The blood electrolytes (Na+, K+ and Cl-) and blood gases (PO2 and PCO2) did not show any significant changes in both groups; however, base excess was significantly higher in uraemic animals. The effects produced by the combination on different systems were transient and values normal as the effect of the drugs wore off. The results suggest that the combination when used epidurally in uraemic goats produced effective and safe surgical analgesia.

Xylazine, Ketamine and their Combination for Lumbar Epidural Analgesia in Water Buffalo Calves (Bubalus bubalis)

The study was conducted to evaluate the effects of xylazine individually (0.05 mg/kg), ketamine individually (2.5 mg/kg), and a combination of xylazine and ketamine (0.05 mg/kg and 2.5 mg/kg) after lumbar epidural administration in water buffalo calves. Fifteen non-descript, male water buffalo calves of 6-8 months of age weighing between 55 and 75 kg were randomly placed in three groups (groups A, B and C). The agents were administered at the first lumbar epidural space. Clinico-physiological parameters, such as analgesia, ataxia, sedation, salivation, heart rate, respiratory rate and rectal temperature were studied. Other haematological and biochemical parameters monitored were haemoglobin, packed cell volume, total leukocyte count, plasma glucose, cortisol, protein albumin, globulin, blood urea nitrogen (BUN), creatinine, alanineamino transferase (ALT), sodium, potassium and chloride. The onset of analgesia (mean +/- SEM) was faster in group C (3.2 +/- 0.20 min) compared with that of group B (4.6 +/- 0.22 min) and group A (34.0 +/- 1.86 min). Analgesia of the thorax, flank, inguinal region, hind limbs, perineum and tail was complete in group C, but mild to moderate in groups A and B. Ataxia was severe in group C and mild in groups A and B. Mild to deep sedation was produced by groups A and C animals. Group B animals failed to produce sedation. Longer duration and greater depth of analgesia was produced in animals of group C. Heart rate, respiratory rate and rectal temperature decreased in groups A and C. The haematological parameters decreased in all the groups. The biochemical parameters like glucose, cortisol, BUN, creatinine, and ALT increased in all the animals. However, total proteins and albumin decreased in the three groups. The plasma electrolytes sodium, potassium and chloride did not show any significant change. The results of this study indicated a possible synergistic analgesic interaction between epidurally administered xylazine and ketamine, without causing any marked systemic effects in water buffalo calves.

Comparison of ropivacaine with a combination of ropivacaine and fentanyl for the caudal epidural anaesthesia of mares

Two groups of six mares aged from eight to 18 years were anaesthetised by caudal epidural injections of ropivacaine (0.5 per cent, 0.1 mg/kg) or a combination of ripovacaine (0.08 mg/kg) and fentanyl (100 microg) in a randomised study. The onset of anaesthesia was significantly more rapid (P<0.001) and it lasted significantly longer (P<0.001) in the group anaesthetised with the combination of drugs. The surgical comfort scores of the group anaesthetised with the combination were higher than those of the group anaesthetised with ropivacaine alone (P<0.001), and the quality of intraoperative analgesia, as assessed by the surgeon, was significantly improved. There were no differences between the groups in their average scores for the levels of ataxia and sedation, in their behaviour, or in the incidence of side effects.

Influence of Yohimbine and Atipamezole on Haemodynamics and ECG after Lumbosacral Subarachnoid Administration of Medetomidine in Goats

Effects of intravenous yohimbine and atipamezole on haemodynamics and electrocardiogram (ECG) were studied after lumbosacral subarachnoid administration of medetomidine in eight goats. All goats received lumbosacral subarachnoid medetomidine at a dosage of 0.01 mg/kg followed by yohimbine (0.25 mg/kg) or atipamezole (0.005 mg/kg) intravenously 45 min after administration of medetomidine, in a randomized crossover design, in right lateral recumbency keeping a gap of 1 week between each trial. Heart rate, respiratory rate, rectal temperature, mean arterial pressure (MAP), mean central venous pressure (MCVP) and ECG were determined. Goats were observed for sedation and urination. All goats showed sedation and depression after medetomidine administration became alert within 2-5 min after reversal. Bradycardia and bradypnoea were the consistent findings after medetomidine injection. Tachycardia and tachypnoea were recorded within 2-5 min after reversal in both groups. A decrease in MAP and an increase in MCVP were seen after medetomidine administration in both groups. Effects of yohimbine and atipamezole on the reversal of MAP and MCVP were more or less the same and statistically non-significant (P > 0.05) in all animals. The ECG changes were non-significant (P > 0.05) in both groups. It is concluded that in the given dose rates both yohimbine (0.25 mg/kg) and atipamezole (0.005 mg/kg) produced equal reversal of the sedation, CNS depression, cardiopulmonary and ECG changes induced by subarachnoid administration of medetomidine in goats indicating that most of the actions of medetomidine were mediated via activation of alpha2-adrenergic receptors.

Interaction Between Epidurally Administered Ketamine and Pethidine in Dogs

The present study was designed to test the hypothesis that a synergistic interaction could be recorded after epidural administration of ketamine-an N-methyl-D-aspartate (NMDA) antagonist and pethidine--an opioid agonist. Twelve adult mongrel dogs of either sex were randomly divided in three groups A, B and C of four animals each. Ketamine (5%) at 2.5 mg/kg and pethidine (3%) 2 mg/kg were injected at lumbosacral epidural space in animals of groups A and B, respectively. In animals of group C ketamine (2.5 mg/kg) and pethidine (2 mg/kg) were injected. Heart rate increased significantly up to 15 min in group A, whereas in groups B and C, the increase was non-significant for a period of 10 and 45 min, respectively. Respiration increased gradually up to 45-60 min in group A and for 15-20 min in group B. However, in animals of group C respiration fell below the baseline during the first 10-15 min and then returned near the baseline. Rectal temperature decreased only marginally in all the groups. Ketamine alone produced complete analgesia at tail and perineal region for a period of 5-10 min and then moderate analgesia for the next 20-30 min. Analgesia at the flank was moderate to complete between 5 and 15 min. In group B complete analgesia was only moderate at the tail and perineal region up to 30 min. In animals of group C, complete analgesia was observed only at perineal region for a very short period (5 min). Analgesia was not associated with sedation in any of the groups but animals of groups A and C showed signs of motor incoordination. Results of the study suggest rather antagonistic than synergistic interaction between epidurally administered ketamine and pethidine. Further studies are needed to confirm the antagonistic interaction between the two drugs.

Analgesic and systemic effects of ketamine, xylazine, and lidocaine after subarachnoid administration in goats

OBJECTIVE

To determine the effects of ketamine hydrochloride, xylazine hydrochloride, and lidocaine hydrochloride after subarachnoid administration in goats.

ANIMALS

6 healthy goats.

PROCEDURE

In each goat, ketamine (3 mg/kg), xylazine (0.1 mg/kg), lidocaine (2.5 mg/kg), and saline (0.9% NaCI) solution were injected into the subarachnoid space between the last lumbar vertebra and first sacral vertebra (time 0). Analgesic, ataxic, sedative, cardiovascular, and respiratory effects and rectal temperature were evaluated before (baseline) and 2, 5, 10, 15, and 30 minutes after administration and at 30-minute intervals thereafter as needed.

RESULTS

Administration of anesthetics induced varying degrees of analgesia. Onset of the analgesic effect was more delayed for xylazine (mean +/- SD, 9.5 +/- 2.6 minutes) than for ketamine (6.7 +/- 2.6 minutes) or lidocaine (3.5 +/- 1.2 minutes). Duration of analgesia induced by xylazine (88.3 +/- 15 minutes) was twice as long as the duration of analgesia induced by ketamine (48.8 +/- 13.5 minutes) but similar to that induced by lidocaine (66.5 +/- 31 minutes). Xylazine induced bradycardia, whereas ketamine caused a nonsignificant increase in heart rate. Xylazine induced a reduction in arterial pressure, whereas ketamine or lidocaine did not affect arterial pressure.

CONCLUSIONS AND CLINICAL RELEVANCE

Subarachnoid administration of xylazine in goats resulted in longer duration of analgesia of the tail, perineum, hind limbs, flanks, and caudodorsal rib areas than administration of ketamine or lidocaine. However, xylazine caused bradycardia and respiratory depression. Additional studies are needed to determine whether the analgesia would be sufficient to allow clinicians to perform surgical procedures.

Analgesic, sedative and haemodynamic effects of spinally administered romifidine in female goats

The present study was designed to evaluate the analgesic, sedative and haemodynamic effects of spinally administered romifidine in goats. Ten female healthy goats weighing 14-18 kg were randomly divided into two groups, I and II, of five animals each. Romifidine was administered spinally at rates of 50 and 75 microg/kg body weight in the animals of groups I and II, respectively, into the lumbosacral space. The treatments were compared based on their effects on analgesia, sedation, ataxia, heart rate, respiratory rate, rectal temperature, mean arterial pressure, central venous pressure, electrocardiogram and haemato-biochemical parameters. The objective parameters were analysed statistically using paired t-test and Duncan's multiple range test. Depth of analgesia was measured by recording the response to pin prick at different regions and was graded on a scale from 0 to 3. Moderate to complete analgesia was recorded at perineum and flank in both groups. Sedation was moderate in both groups. Ataxia was observed in all the animals but it was more pronounced in group II. Heart rate decreased significantly (P < 0.01) in both groups. A decrease in respiration rate was also recorded in both groups but it was more significant (P < 0.01) and for longer duration in group II as compared to group I. A slight increase in rectal temperature was also observed in both groups. Mean arterial pressure decreased and central venous pressure increased significantly (P < 0.01) in both groups but changes were more pronounced in group II. Electrocardiogram changes in group I included bradycardia, increased QT interval and increased or biphasic T wave but in animals of group II, in addition to these changes, occasional sinus dysrhythmia, increased PR interval and second-degree heart block were also recorded. Haemoglobin and packed cell volume decreased non-significantly in both groups. A significant (P < 0.01) increase in blood glucose and non-significant changes in plasma proteins, urea nitrogen and creatinine were recorded in both groups. The results of the study revealed that romifidine at the rate of 50 microg/kg could produce moderate to complete analgesia of perineum and flank after spinal administration into the lumbosacral space in goats. The analgesia could not be enhanced further by increasing the dose of romifidine up to 75 microg/kg, however, ataxia and cardiopulmonary and haemodynamic side-effects became more apparent.

Physiologic and biochemical effects of subarachnoidally administered xylazine and medetomidine in goats

Clinicophysiological, haematological and biochemical effects of xylazine (0.05mgkg(-1)) and medetomidine (0.01mgkg(-1)) were studied in nine adult goats after lumbosacral subarachnoid administration. The onset of analgesia by xylazine and medetomidine was observed in 9.11+/-1.07 and 8.66+/-2.37min (mean+/-S.E.), respectively. Both alpha(2)-agonists produced moderate analgesia of hind quarter, perineum and flank, mild ataxia and sedation. The duration of analgesia after xylazine administration was 134.44+/-8.87min and that after medetomidine was 158.33+/-9.96min (mean+/-S.E.). Xylazine and medetomidine induced significant (p<0.05) decrease in heart rate, respiratory rate and hypothermia. Haemoglobin (Hb), packed cell volume (PCV) and total leukocyte count (TLC) decreased significantly. Changes in the physiological and haematological parameters were transient in nature. Xylazine and medetomidine produced a significant (p<0.05) increase in creatinine and glucose levels. However, these parameters fluctuated within normal range and started to recover within 120min. However, serum urea nitrogen (SUN), serum chloride, sodium and potassium did not show any significant change. The effects produced by xylazine and medetomidine were however, comparable at these dose levels. The study indicates that xylazine at 0.05mgkg(-1) and medetomidine at 0.01mgkg(-1) did not induce any serious alteration in the physiological, haematological and biochemical parameters and can be safely used in inducing hind quarter, flank and perineal analgesia in goats.

Analgesic, behavioural and cardiopulmonary effects of epidurally injected medetomidine (Domitor) in goats

This study was carried out in order to evaluate the analgesic, sedative, immobilizing and cardiopulmonary effects of medetomidine in goats after lumbosacral epidural injection of three (10, 20 and 30 micrograms/kg body weight) doses. The volume of the injection for all three medetomidine doses was 5 ml in sterile water. Seventeen clinically healthy, Small East African goats of either sex and weighing between 12 and 22 kg (mean +/- SD; 14.8 +/- 2.5 kg body weight) were used. The animals were randomly assigned to two groups. Seven goats were used for evaluating analgesic, behavioural and cardiopulmonary effects while 10 were used for experimental surgery. The cardiopulmonary values and rectal temperature were determined and recorded at time 0 (preinjection) and at 5, 10, 15, 20 and 30 min, and thereafter at 15-min intervals up to 180 min after injection. Analgesia of the flank and perineum was determined at time 0 (preinjection) and at 5, 10, 15, 30, 60, 120 and 180 min using a scoring system. The spread of analgesia to the thorax, neck, forelimbs and head was also determined and recorded. The onset and duration of lateral recumbency was noted and recorded. Medetomidine at the given doses induced variable cardiopulmonary depression, which was not detrimental to the animals. All three doses (10, 20 and 30 micrograms/kg) of medetomidine induced adequate analgesia of the flank and perineum. Analgesia extended to the thorax, forelimbs, neck and head. The duration of lateral recumbency was 136 and 166 min for the 20 and 30 micrograms/kg medetomidine doses, respectively. The duration of lateral recumbency was not determined for the animal given 10 micrograms/kg medetomidine. Signs of sedation (lowering of the head, drooping of the lower lip, partial to complete closure of the eyes and salivation) were noted after administration of all three doses. It can be concluded from this study that all three doses induced adequate analgesia of the flank and perineum. Surgical analgesia of the flank of goats was achieved after lumbosacral epidural administration of 20 micrograms medetomidine/kg, diluted in 5 ml of sterile water. Surgery was not performed with the other doses (10 and 30 micrograms/kg) of medetomidine.