Veterinary Anaesthesia and Analgesia, 2009, 36, 352–360 doi:10.1111/j.1467-2995.2009.00473.x RESEARCH PAPER Sedative and analgesic effects of romifidine in camels (Camelus dromedarius) Mohamed Marzok* MVSc, PhD & Sabry El-Khodery MVSc, PhD *Faculty of Veterinary Medicine, Department of Surgery, Anesthesiology and Radiology, Kafer-Elsheikh University, Egypt Faculty of Veterinary Medicine, Department of Internal Medicine and Infectious Diseases, Mansoura University, Mansoura, Egypt Correspondence: Mohamed Marzok, Faculty of Veterinary Medicine, Department of Surgery, Anesthesiology and Radiology, Kafer-Elsheikh University, Egypt. E-mail: marzok2000@hotmail.com Abstract Objective To evaluate the clinical effectiveness and the sedative and analgesic effects of intravenous (IV) romifidine in camels. Study design Randomized prospective study. Animals Eighteen healthy adult Dromedary camels. Methods Romifidine was administered IV to camels (n = 6) at three different doses (40, 80 or 120 lg kg)1). Time of onset, degree and duration of sedation and analgesia were recorded immediately after drug administration. Heart rate, respiratory rate, ruminal contractions, muscle relaxation, response to auditory and tactile stimulation, distance between ears, distance from lower lip to the ground, and degree of ataxia were also recorded preadministration and at 5, 15, 30, 45, 60, 90, 120 and 180 minutes post-administration. Plasma glucose, blood urea nitrogen and creatinine were measured. Results Romifidine produced dose dependent sedation and analgesia. Significant decreases in heart rate (p < 0.001), ruminal contractions (p < 0.05), distance from lower lip to the ground (p < 0.001), response to auditory and tactile stimuli (p < 0.01), and significant increases in the degree of ataxia (p < 0.01), distance between the ear tips 352 (p < 0.001) and blood glucose (p < 0.01) concentration were recorded after administration of romifidine until recovery. However, no significant changes in rectal temperature and respiratory rate were recorded. Conclusions and clinical relevance Intravenous administration of romifidine at three different doses appeared to be an effective sedative and analgesic agent for camels. Bradycardia, ruminal atony, and hyperglycemia were the most important adverse effects after IV administration of romifidine. The IV administration of romifidine at a dose rate of 120 lg kg)1 caused profound sedation and analgesia. Romifidine could be used for chemical restraint for a variety of diagnostic and minor surgical procedures in camels. Keywords analgesia, camel, romifidine, sedation. Introduction Despite the great advances in the use and understanding of sedative drugs in domestic animals, there have been few reports of their use in camels (Fouad 2000). Chloropromazine hydrochloride, propoinyl promazine and acepromazine have been evaluated as sedatives in camels (Khamis et al. 1973; Ali et al. 1989). In recent years sedation with alpha-2 adrenoceptor agonists (xylazine, detomidine, medetomidine and Sedative and analgesic effects of romifidine in camels M Marzok and S El-Khodery romifidine) has been used for restraint, the calming of camels or stress reduction (Ali 1988). If these agents were inadequate to allow completion of involved surgical procedures, supplementation with local analgesic or general anaesthesia has been used (White et al. 1986; Fahmy et al. 1995). Xylazine was the initial alpha-2 agonist to be used for camel sedation (Denning 1972). Xylazine at a dose rate of 0.25 mg kg)1, IM was adequate for many clinical uses in camels and superior to chloropromazine and propionyl promazine (Khamis et al. 1973). Increasing the dose to 0.4 mg kg)1 IM, resulted in sternal recumbency in 11–15 minutes and a recumbency time of 1–2 hours (Custer et al. 1977; Penshin et al. 1980). Preliminary trials with detomidine indicated that IV administration at a dose rate of 25, 50 and 75 lg kg)1 produced profound sedation and analgesia in camels (Hall et al. 2001; El-Maghraby & Al-Qudah 2005). Romifidine is a selective alpha-2 adrenoceptor agonist drug (England et al. 1996) that is commonly administered systemically or spinally to bring about sedation and analgesia in horses (England et al. 1992; Gasthuys et al. 1996; Kerr et al. 1996; Rossetti et al. 2008), dogs (England et al. 1996; Lemke 1999), cats (Selmi et al. 2004), cattle (Prado et al. 1999; Fierheller et al. 2004), sheep (Celly et al. 1997) and goats (Aithal et al. 2001; Kinjavdekar et al. 2002, 2006). To the authors’ knowledge, sedation and analgesia in camels using romifidine have not been described. Therefore, the present study was designed to evaluate the clinical usefulness, sedative and analgesic effect as well as biochemical changes associated with intravenous administration of romifidine at three dose rates in camels (Camelus dromedarius). Materials and methods Experimental animals and drugs Eighteen dromedary camels were used in this study (nine males and nine nonpregnant females). Mean ± SD age was 7.92 ± 3.15 years old: mean weight was 391.7 ± 63.4 kg. All animals were considered healthy on the basis of results of physical examination. Romifidine (Sedivet, 10 mg mL)1, Boehringer Ingelheim, Vetmedica GmbH, Germany) was administered IV at three dose rates. Study protocol The study protocol was approved by the Animal Care Committee of the Kafer-Elsheikh University. Camels were allocated randomly to three groups with six camels in each group. The experiments were performed outdoors in a quiet environment and natural daylight. At the beginning of each experiment, resting rectal temperature, ruminal contractions, pulse and respiratory rates were assessed and a complete blood count was made to assess the animals’ health. Romifidine was injected IV at a dose of 40, 80 or 120 lg kg)1 body weight to the three groups. Prior to injection all the animals were starved for 24 hours and water was withheld for 12 hours. The injections were performed through a 20-gauge catheter placed into a jugular vein. All the injections were administered with the camels in sternal recumbency. The animals were allowed to stand immediately after injection. Evaluation of romifidine effects Heart rate, respiratory rate, ruminal contractions, muscle relaxation, responses to auditory and tactile stimulation as well as the degree of ataxia and analgesia were recorded immediately (time 0) preadministration and at 15, 30, 45, 60, 90, 120 and 180 minutes post-administration. Heart and respiratory rates were assessed by clinical methods. Ruminal contraction was assessed by auscultation (Tefera 2004). Muscle relaxation was assessed via measurement of the height of the lower lip from the floor and the distance between the ear tips. Responses to auditory and tactile stimulation, degree of ataxia and degree of analgesia and sedation were evaluated and recorded blindly on a visual analogue scale by a single clinician at the same time points. Response to auditory stimulation was scored by evaluating responses to banging on an empty metal bucket or metal bar close to the camel’s head (0 = nonresponse; 10 = marked rapid response to stimuli, as characterized by raising of the head and turning to face the noise, or making evasive movements). Response to tactile stimulation was scored by evaluating responses to focal pressure with a pen tip on the coronary band or dorsal metatarsal area of a hind limb (0 = no response; 10 = brisk evasive response and retraction of the limb). The area that induced the most marked response, in each individual prior to treatment, was used for subsequent  2009 The Authors. Journal compilation  2009 Association of Veterinary Anaesthetists, 36, 352–360 353 Sedative and analgesic effects of romifidine in camels M Marzok and S El-Khodery evaluation. Degree of ataxia was also evaluated by walking the camel for a distance (0 = unable to walk or move; 10 = able to walk and step clearly with all four feet) (Freeman & England 1999). The sedative effect of romifidine was assessed using a descriptive scale (Table 1). The time of onset and score of sedation were recorded immediately after drug administration. The duration of sedation was determined as the time from the start of sedation to a return of the sedation score to zero. Onset and depth of analgesia was qualitatively assessed by recording the response of the animal to pinching with a haemostat clamp (closed to the first ratchet). Pinching was applied at the shoulder, flank area, perineum and dorsal metatarsal area of the hind limb. The clamp was left in place for 5 seconds or until a response was evident. Positive pain responses were defined as purposeful avoidance movements of head, neck, trunk, limbs and tail, attempts to kick and bite, and turning of the head toward the stimulus site. As soon as the camel showed one of the defined responses, the investigator removed the clamp or stopped the stimulus. Depth of analgesia was graded on a scoring system from 0 to 3 as described in horses by Jöchle & Hamm (1986); 0, no analgesia (strong response to noxious stimulus); 1, mild analgesia (moderate response); 2, moderate analgesia (very weak and occasional response); 3, complete analgesia (no response to noxious stimulus). The time of onset, score and duration of analgesia were recorded for 3 hours after drug administration. The animal’s eyes were covered at the time of stimulation to avoid any visually provoked response. Penile prolapse, expelling the dulla from the mouth, and frequency of urination were also recorded. Blood samples (5 mL) were collected from the jugular vein at 0, 5, 15, 30, 45, 60, 90, 120 and 180 minutes after romifidine injection for determination of plasma glucose and serum blood urea nitrogen and creatinine concentrations. These parameters were measured using commercial test kits (Spinreact Co., Barcelona, Spain). Statistical analysis Data analyses were performed using a statistical software program (GMP for windows Version 5.1; SAS Institute, Cary, NC, USA). Mean values and standard deviation for each assessed variable at each time point were calculated. Repeated measures MANOVA (with repeated measures on treatment and time) were used to determine the main effect of dose and time. Wilks’ Lambda test was selected to evaluate within group interactions and evidence of time · group interactions. Where Wilks’ Lambda test indicated a statistically significant difference between groups, one way ANOVA with Tukey-Kramer HSD post-hoc multiple comparison test was used to identify which group was statistically different from the rest. Differences between means at p < 0.05 were considered significant. Results In the present study, based on dose-time interaction, heart rate showed a significant decrease (MANOVA, p < 0.01; Wilks’ Lambda for dose-time interaction, Table 1 Clinical description of sedation scores after using of IV romifidine in camels Score Criteria Clinical description 0 No sedation 1 Mild sedation 2 Moderate sedation 3 Deep sedation Normal frequency and velocity of movement, ear, head and neck carriage, eye alertness, lip and lid apposition, tongue position, postural tone, stance Slightly decreased frequency and velocity of movement, lower ear and head carriage, deviation of the neck, reduced eye alertness, drooping of lower lip and ptosis of upper lid, hanging or protrusion of the tongue out of the mouth, slight base-wide stance, slightly relaxed postural tone Moderately decreased frequency and velocity of movement, obvious ear tip separation and head droop, increased base-wide stance, appearance of crossed legs, buckled knees and/or fetlocks, more relaxed postural tone Markedly decreased frequency and velocity of movement, pronounced ear tip separation, marked lowering of the head, drooping of the lower lip and ptosis of the upper eyelid, marked deviation of the neck, greatly reduced eye alertness, extreme protrusion of the tongue out of the mouth, markedly increased base-wide stance, increased occurrence and severity of crossed legs, buckled knees and/or fetlocks, pronounced loss of postural tone 354  2009 The Authors. Journal compilation  2009 Association of Veterinary Anaesthetists, 36, 352–360 Sedative and analgesic effects of romifidine in camels M Marzok and S El-Khodery p < 0.001). The lowest rate was recorded at a dose rate of 120 lg kg)1 at 45 and 60 minutes postadministration (Fig. 1). Ruminal contractions also showed a significant decrease related to dose and time (MANOVA, p < 0.05; Wilks’ Lambda for dosetime interaction, p < 0.05). The lowest rate was 0.8 ± 0.4 contractions per 5 minutes, which was recorded with 120 lg kg)1 at 30 minutes postadministration (Fig. 2). Respiratory rate and rectal temperature did not show significant variation throughout the study. Lip height from the ground decreased significantly (MANOVA, p < 0.01; Wilks’ Lambda for dosetime interaction, p < 0.001). The lowest distance was recorded at 30 minutes post-administration Figure 1 Heart rate (mean ± SD) in camels after IV administration of different doses of romifidine. *The effect of this dose differs significantly from the other doses at the given time (p < 0.05). Figure 2 Ruminal contractions (mean ± SD) in camels after IV administration of different doses of romifidine. *The effect of this dose differs significantly from the other doses at the given time (p < 0.05). using 80 and 120 lg kg)1 (Fig. 3). The distance between the ear tips significantly increased (MANOVA, p < 0.01; Wilks’, Lambda for dose-time interaction, p < 0.001) and the largest distance was recorded at 30 minutes post-administration with 80 and 120 lg kg)1 (Fig. 4). Response to auditory stimulation showed a significant decrease (MANOVA, p < 0.01; Wilks’ Lambda for dose-time interaction, p < 0.01). The lowest score was produced by 120 lg kg)1 at 15 and 30 minutes post-administration (Table 2). The response to tactile stimulation decreased significantly (MANOVA, p < 0.01; Wilks’, Lambda, p < 0.01) by time and dose. The lowest scores were recorded with Figure 3 Distance from lower lip to the ground (mean ± SD) in camels after IV administration of different doses of romifidine. *The effect of this dose differs significantly from the other doses at the given time (p < 0.05). Figure 4 Distance between ear tips (mean ± SD) in camels after IV administration of different doses of romifidine. *The effect of this dose differs significantly from the other doses at the given time (p < 0.05).  2009 The Authors. Journal compilation  2009 Association of Veterinary Anaesthetists, 36, 352–360 355 Sedative and analgesic effects of romifidine in camels M Marzok and S El-Khodery Table 2 Response scores to auditory stimulation (median and range) in camels pre- and post-administration of different doses of romifidine Time after romifidine injection (minutes) Dose (lg kg)1) 0 5 15 30 45 60 90 120 180 40 80 120 10 10 10 2 (1–3) 2 (1–2) 2 (1–2) 2 (1–3)a 2 (1–2)ab 1 (1–2)c 2 (2–3)a 2 (2–3)a 1 (1–2)b 3 (2–3)a 3 (3–4)ab 2 (2–3)b 5 (4–6)a 6 (4–5)a 4 (2–3)b 6 (6–7)a 6 (5–6)a 4 (4–5)b 10 (8–10)a 8 (8–9)b 7 (7–8)c 10 (10–10)a 10 (10–10)a 8 (8–9)b Variables with different superscript letters in the same column are significantly different at p < 0.05. MANOVA fit, p < 0.01. Wilks’ Lambda test for time effect, p < 0.01. Wilks’ Lambda test for dose · time interaction, p < 0.01. at 30 minutes post-administration (median, 0; range, 0–2) with 120 lg kg)1 (Table 4). Although all camels remained in a standing position after administration of romifidine at a dose rate 40 or 120 lg kg)1 at 45 minutes. (Table 3). The degree of ataxia (scores) was increased significantly (MANOVA, p < 0.01; Wilks’ Lambda, p < 0.01) for 120 minutes post-administration The lowest score was recorded Table 3 Response scores to tactile stimulation (median and range) in camels pre- and post-administration of different doses of romifidine Time after romifidine injection (minutes) Dose (lg kg)1) 0 5 15 30 45 60 90 120 180 40 80 120 10 10 10 3 (2–4) 2 (2–3) 2 (1–4) 3 (2–4) 2 (2–3) 2 (1–4) 3 (2–3) 3 (2–4) 2 (2–3) 4 (3–4)a 3 (3–6)a 1 (1–4)b 6 (4–6)a 4 (3–4)b 2 (2–3)c 7 (6–8)a 5 (5–6)b 5 (4–6)c 10 (10–10)a 8 (7–10)b 6 (6–7)c 10 (10–10)a 10 (10–10)a 8 (7–9)b Variables with different superscript letters in the same column are significantly different at p < 0.05. MANOVA, p < 0.01. Wilks, Lambda test for time effect, p < 0.01. Wilks, Lambda test for dose · time interaction, p < 0.01. Table 4 Degree of ataxia (median and range) in camels pre- and post-administration of different doses of romifidine Time after romifidine injection (minutes) Dose (lg kg)1) 0 5 15 30 45 60 90 120 180 40 80 120 10 10 10 6 (5–7)a 4 (3–5)b 2 (2–4)c 5 (4–6)a 3 (2–3)b 1 (1–2)c 6 (6–7)a 3 (2–3)b 0 (0–2)c 6 (6–7)a 3 (3–4)b 1 (1–2)c 8 (8–9)a 5 (4–6)b 3 (2–3)c 10 (10–10)a 8 (7–8)b 3 (3–4)c 10 (10–10)a 10 (9–10)a 5 (5–6)b 10 (10–10) 10 (10–10) 10 (8–10) Variables with different superscript letters in the same column are significantly different at p < 0.05. MANOVA fit, p < 0.01. Wilks, Lambda test for time effect, p < 0.01. Wilks, Lambda test for dose · time interaction, p < 0.01. 356  2009 The Authors. Journal compilation  2009 Association of Veterinary Anaesthetists, 36, 352–360 Sedative and analgesic effects of romifidine in camels M Marzok and S El-Khodery 80 lg kg)1 body weight, the animals which received 120 lg kg)1 assumed sternal recumbency within 20 minutes of drug administration. Sedation Intravenous injections of romifidine induced apparent sedative effects within 2–3 minutes. No difference in onset was detected between the three doses of romifidine. All animals remained calm and appeared to be unaware of their surroundings. Drooping of the lower lip, head, upper eyelid and external conchea of the ear, deviation of the neck and protrusion of the tongue from of the mouth were observed. Variable degrees of sedation were induced; the degree of sedation was more or less dose dependent and rated from mild to deep. Depth of sedation induced by 120 lg kg)1 (sedation score 3) was greater than that induced by either 40 lg kg)1 (sedation score 1) or 80 lg kg)1 (sedation score 1 and 2) (Table 5). The sedative effect persisted for 37 ± 4, 51 ± 4 and 65 ± 5 minutes after intravenous injection of romifidine at 40, 80, and 120 lg kg)1, respectively. Analgesia Intravenous administration of romifidine produced an apparent analgesic effect within 45–60 minutes. No difference in onset was detected between the three doses of romifidine. The period of analgesia was shorter than the period of sedation (Table 5). The analgesic effect persisted for 21 ± 7, 34 ± 9 and 46 ± 4 minutes after IV injection of romifidine at 40, 80, and 120 lg kg)1, respectively. Intravenous administration of romifidine at a dose rate of 40 lg kg)1 induced poor analgesia which ranged from 0 (no obvious analgesia) to score 1 (mild analgesia). The analgesic effect of 80 lg kg)1 produced moderate analgesic effects (score 2), while the analgesic effect of 120 lg kg)1was excellent (score 3) as indicated by a lack of response to noxious stimuli. No adverse reactions were observed at the administration site. Mild salivation and lacrimation were the observed adverse effect. Protrusion of the penis was not observed in any animal. Protrusion of the dulla from the mouth was observed at the time of recovery. Frequent urination commencing about 60–90 minutes after administration of romifidine was observed during this study. All camels urinated more than once (range 2–5 times). Biochemical analysis showed that the intravenous administration of the three different doses of romifidine produced a significant increase in plasma glucose concentrations at the three tested doses (MANOVA, p < 0.01; Wilks’ Lambda, p < 0.01). The highest concentration was recorded at 90 minutes post-administration of 120 lg kg)1 (Fig. 5). Discussion Table 5 The effect of various doses of romifidine on the duration (mean ± SD) and score for sedation and analgesia. The durations for the 40 lg kg)1 and 80 lg kg)1 doses are the results from the two and five animals, respectively that became sedated Sedation Dose of romifidine Duration (minutes) 40 lg kg)1 37 ± 4a 80 lg kg)1 51 ± 4b 120 lg kg)1 65 ± 5c The aim of the present study was to investigate the sedative and analgesic effects of romifidine in cam- Analgesia Score* 0 1 0 1 2 3 (n (n (n (n (n (n = = = = = = 4) 2) 1) 2) 3) 6) Duration (minutes) 21 ± 7a Score* 34 ± 9b 0 (n = 4) 1 (n = 2) 2 (n = 6) 46 ± 4c 3 (n = 6) Means in the same column with different superscript letters are significantly different at p < 0.05. *0, no effect; 1, mild degree; 2, moderate degree; 3, deep degree. Figure 5 Plasma glucose concentration (mean ± SD) in camels after IV administration of different doses of romifidine. *The effect of this dose differs significantly from the other doses at the given time (p < 0.05).  2009 The Authors. Journal compilation  2009 Association of Veterinary Anaesthetists, 36, 352–360 357 Sedative and analgesic effects of romifidine in camels M Marzok and S El-Khodery els. Baseline values for all variables were within normal limits for camels (Nazifi & Maleki 1998). These observations indicated that the camels were healthy and calm at the time of administration of the drug. The sedative effects of romifidine at different doses and routes of administration have been studied in different species of animals (England et al. 1992; Gasthuys et al. 1996; Kerr et al. 1996; England et al. 1996; Lemke 1999; Selmi et al. 2004; Prado et al. 1999; Fierheller et al. 2004; Celly et al. 1997; Aithal et al. 2001; Kinjavdekar et al. 2002, 2006). However, there is no reported study on the use of romifidine for camel sedation. Our study showed that romifidine is capable of producing significant, dose dependent sedation. Onset of sedation started soon (2 minutes) after the intravenous injection of romifidine. No difference in onset was detected between the different doses of romifidine. Our findings describing the sedation qualities of romifidine were similar to those reported for xylaxine and detomidine (Khamis et al. 1973; Custer et al. 1977; Penshin et al. 1980; El-Maghraby & Al-Qudah 2005) but vary qualitatively with regard to the drug-related effects. Analgesia is an important quality of alpha-2 agonists (England & Clarke 1996). The camel is a large animal, entailing a risk of injury to personnel. So, in camel clinical practice, the use of drugs to produce sedation as well as analgesia is mandatory for some routine examinations and most surgical interventions. The alpha-2 agonist drugs are frequently used in the camel to perform immobilization and provide sedation, superficial analgesia, and they can facilitate placement of local or regional analgesic blocks. A number of pain assessment models have been described for use in the horse. In our study, mechanical stimuli through pinching with a hemostat clamp (Jöchle & Hamm 1986; Brunson et al. 1987) was used. In this study romifidine provided temporary analgesia. Maximal effects were present at 45–60 minutes and gradually decreased to baseline levels after about 90 minutes. Of the three tested doses, the 40 lg kg)1 dose produced analgesia of the shortest duration. Detomidine produced similar analgesia but the duration of effect was shorter than was found in the current study (El-Maghraby & Al-Qudah 2005). The analgesic period was shorter than the sedation period. Similar results were obtained after the use of xylaxine and detomidine (Bolbol et al. 1980; El-Maghraby & Al-Qudah 2005). Analgesia differed significantly 358 among treatments. The analgesic effect of romifidine in camels was dose dependent, while the low dose (40 lg kg)1) had no analgesic effect in four animals, the next higher dose (80 lg kg)1) provided moderate analgesia in all animals (scores of 2) and the highest dose produced profound analgesia in all animals (scores of 3). This is in agreement with that reported after the use of detomidine (El-Maghraby & Al-Qudah 2005). Despite the differences observed in the analgesia scores following administration of romifidine at the three different doses, one must interpret the results cautiously as agents that influence sedation, motor reactions, and autonomic reflexes are likely to influence the observed response to nociceptive stimuli (Ansah et al. 1998). The observed degree of ataxia was dose related and all the camels receiving 120 lg kg)1 became recumbent. This result was in agreement with that reported after the use of detomidine (El-Maghraby & Al-Qudah 2005). The distance between the lower lip and the ground appeared to be an excellent indicator of the sedative effects of alpha-2 adrenoceptor agonists because it reflected muscle relaxation and reduced awareness. In the present study, there was a significant decrease in the distance of lower lip from the ground observed within 5 minutes post-administration. The lowest dose produced the least change in this parameter except at 15 minutes when there was no difference between the doses. There was no difference between the 80 and 120 lg kg)1 doses except at 180 minutes. The distance between the ear tips significantly increased and was also used as an indicator of sedative effects, because position of the ears is determined by the facial muscles, which relax with alpha-2 agonists (Freeman & England 1999). Degree and duration of lowering of the head may be involved in the development of head oedema that is observed in some camels following sedation. The reported significant decrease in the auditory responses associated with romifidine suggested that rapid and profound sedation was achieved following IV administration of romifidine. The IV administration of romifidine induced a significant decrease in heart rate, which exhibited the lowest rate at 45 and 60 minutes post-administration at a dose of 120 lg kg)1. This result was in accordance with that recorded for other alpha-2 adrenoceptor agonists in dromedary camels after premedication with xylazine (Khamis et al. 1973; Bolbol et al. 1980; White et al. 1987), and detomidine (El-Maghraby & Al-Qudah 2005). Bradycardia  2009 The Authors. Journal compilation  2009 Association of Veterinary Anaesthetists, 36, 352–360 Sedative and analgesic effects of romifidine in camels M Marzok and S El-Khodery following administration of alpha-2 adrenoceptor agonist may be due to central stimulation mediated through the vagus nerve and to a reduction in sympathetic tone (Hall et al. 2001). A significant decrease in ruminal contractions of camels receiving romifidine was also recorded. A similar inhibition of ruminal contractions induced by romifidine was observed in goats (van Miert et al. 1994). Although alpha-2 agonists have a relaxing effect on the gastro-intestinal tract and are associated with decreased motility (Hall et al. 2001), marked tympany was not observed in our camels. No significant effect on respiratory rate and the rectal temperature of treated camels was observed after the administration of three doses of romifidine. This was similar to that previously recorded after use of xylazine (Penshin et al. 1980) and detomidine (El-Maghraby & Al-Qudah 2005). Salivation was mild with the three doses in this study. In contrast, cattle which received romifidine had obvious increases in salivation (Prado et al. 1999; Fierheller et al. 2004). The marked increase in urine production after the administration of alpha-2 agonists was thought to be through inhibition of antidiuretic hormone release (Hall et al. 2001). The absence of penile protrusion, even in deeply sedated camels, was consistent with the result observed after sedation of camels with xylazine (Khamis et al. 1973) and detomidine (El-Maghraby & Al-Qudah 2005). The first authors attributed this observation to some anatomical features; where the preputial orifice of the dromedary is relatively narrow and surrounded by muscular tissue of the prepuce, and is directed backwards enabling the protrusion of the penis only in its erect state. The significant hyperglycemia observed following romifidine administration in camels has also been observed after xylazine or detomidine administration in camels (Penshin et al. 1986; Ali et al. 1989; El-Maghraby & Al-Qudah 2005). It may be attributed to an increase in adrenergic activity, a decrease in the secretion or the effect of insulin or an increase in the secretion or activity of glucagons (Custer et al. 1977; Ali et al. 1989). The present study demonstrated that IV administration of romifidine was an effective sedative and analgesic agent for camels. Maximal sedation, analgesia and recumbency was achieved with IV doses of 120 lg kg)1. Romifidine could be used as a good chemical restraint method for a variety of diagnostic and minor surgical procedures with local analgesia if necessary. The findings of this study, in healthy camels, may not be the same as in camels with clinical problems. Therefore, further studies need to be done to evaluate the use of romifidine in combination with other drugs, the side effects of romifidine in camels, as well as the most effective drug to reverse the effects of romifidine in clinical practice. 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