ORAL HALOPERIDOL PREMEDICATION TO REDUCE CAPTURE STRESS PRIOR TO XYLAZINE-KETAMINE ANESTHESIA IN CAPTIVE SPOTTED DEER (AXIS AXIS).

A prospective clinical trial was performed to evaluate the efficacy of haloperidol premedication prior to xylazine-ketamine anesthesia with a goal of reducing capture stress in adult male captive spotted deer (Axis axis). On the morning of the study, deer were fed a banana either containing haloperidol tablets (1 mg/kg) (haloperidol group, n = 10) or without haloperidol (placebo group, n = 10). Six hours postadministration, xylazine (3 mg/kg) and ketamine (2 mg/kg) was administered intramuscularly via a dart. Rectal temperature, heart rate, respiratory rate, and SpO2 (percent hemoglobin saturation) were recorded at 5-min intervals. Blood gas analysis was performed at time 0 (venous blood) and 10 and 20 min (arterial blood) postinduction. Serum cortisol was determined from venous blood (35 min postinduction), following which yohimbine was administered at a dose of 0.15 mg/kg intramuscular and 0.15 mg/kg intravenous. Statistical analysis of repeated measures data was performed with a two-way analysis of variance. Paired data were analyzed with a Wilcoxon rank-sum test (categorical data) or a paired t-test (continuous data). Significance was set at P ≤ 0.05, and results were expressed as mean ± SEM. There was no significant difference in induction time or recovery time between treatment groups. Rectal temperature and heart rate were significantly lower in the haloperidol group. Both groups demonstrated acidosis with venous pH being significantly lower in the placebo group when compared to the haloperidol group. Serum cortisol and arterial plasma lactate were lower in the haloperidol group indicative of reduced stress and physical exertion. Haloperidol premedication proved to be beneficial in reducing capture stress, when administered prior to xylazine-ketamine anesthesia, in spotted deer.

Protocols using detomidine and oxytocin induce ex copula ejaculation in stallions.

Tricyclic antidepressives, such as imipramine, indirectly induce ejaculation by increasing the noradrenaline concentration, which triggers an α-adrenergic response, whereas α-adrenergic agonists, such as xylazine and detomidine, directly trigger ejaculation by activating the α-1 adrenergic receptors. Furthermore, serum oxytocin concentrations in stallions increase drastically before ejaculation, but decline immediately thereafter, implicating the role of this hormone in emission. The objectives of the present study were to: 1) compare the efficiency of various protocols for inducing ex copula ejaculation in stallions, 2) evaluate the benefits of including oxytocin in the protocols, and 3) compare the semen characteristics of ex copula versus in copula ejaculates. Nine protocols were used to induce ex copula ejaculation using various combinations of xylazine (X; 0.66 mg/kg, iv); oxytocin (O; 20 IU, iv), imipramine (I; 3 mg/kg, orally), and detomidine (D; 0.02 mg/kg, iv). Imipramine was given 2 h prior to the administration of α-adrenergic agonist (detomidine or xylazine) and oxytocin. If ejaculation did not occur within 10 min after treatment with an α-adrenergic agonist, a half-dose of the same product was injected. Twelve sexually mature stallions (6-26 y) were used; 9 of 12 stallions responded to the treatment. Two stallions responded to X or XO, four stallions responded to IX and IXO, one stallion responded to DO, and five responded to IDO. Stallions that responded to detomidine did not respond to xylazine. No stallion ejaculated in response to D, ID, or IO. Erections and masturbation occurred only in imipramine-treated stallions. Sperm quality was similar among all the protocols and was not significantly different from those in in copula ejaculates collected with an artificial vagina. In a separate trial, none of these protocols induced ex copula ejaculation in 2-3 y old stallions. The side effects included sialorrhea after imipramine administration in all the stallions and sedation after administration of xylazine or detomidine. In conclusion, the new protocol, IDO, and the traditional protocol, IX, had similar results, with IDO being a useful alternative protocol in stallions for which IX was not effective. Therefore, attempts using both the protocols are encouraged, as stallions that ejaculated upon administration of detomidine did not ejaculate when xylazine was administered, whereas those that responded to xylazine did not respond to detomidine.

Activation in the auditory pathway of the gerbil studied with 18F-FDG PET: effects of anesthesia.

Here, we present results from an 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) study in the Mongolian gerbil, a preferred animal model in auditory research. One major issue in preclinical nuclear imaging, as well as in most of the neurophysiological methods investigating auditory processing, is the need of anesthesia. We compared the usability of two types of anesthesia which are frequently employed in electrophysiology, ketamine/xylazine (KX), and fentanyl/midazolam/medetomidine (FMM), for valid measurements of auditory activation with 18F-FDG PET. Gerbils were placed in a sound-shielding box and injected with 18F-FDG. Two acoustic free-field conditions were used: (1) baseline (no stimulation, 25 dB background noise) and (2) 90 dB frequency-modulated tones (FM). After 40 min of 18F-FDG uptake, a 30 min acquisition was performed using a small animal PET/CT system. Blood glucose levels were measured after the uptake phase before scanning. Standardized uptake value ratios for relevant regions were determined after implementing image and volume of interest templates. Scans demonstrated a significantly higher uptake in the inferior colliculus with FM stimulation compared to baseline in awake subjects (+ 12%; p = 0.02) and with FMM anesthesia (+ 13%; p = 0.0012), but not with KX anesthesia. In non-auditory brain regions, no significant difference was detected. Blood glucose levels were significantly higher under KX compared to FMM anesthesia (17.29 ± 0.42 mmol/l vs. 14.30 ± 1.91 mmol/l; p = 0.024). These results suggest that valid 18F-FDG PET measurements of auditory activation comparable to electrophysiology can be obtained from gerbils during opioid-based anesthesia due to its limited effects on interfering blood glucose levels.

Differential Intraocular Pressure Measurements by Tonometry and Direct Cannulation After Treatment with Soluble Adenylyl Cyclase Inhibitors.

PURPOSE: To validate the increase in intraocular pressure (IOP) caused by soluble adenylyl cyclase (sAC) inhibitors and determine reasons behind variation in IOP measurements performed by tonometry. METHODS: C57BL/6J mice were administered DMSO solubilized sAC inhibitors (KH7 or LRE-1) by intraperitoneal injection. Two hours post-treatment, mice were anesthetized with avertin or ketamine/xylazine/acepromazine (KXA). IOP was measured by a rebound tonometer or direct cannulation of the anterior chamber. Spectral-domain optical coherence tomography was used to measure anterior chamber depth and corneal thickness in live mice. Outflow facility was measured in perfused, enucleated mouse eyes. RESULTS: Compared with DMSO controls, KH7 treatment caused an increased IOP in avertin- and KXA-anesthetized mice when measured by direct cannulation [avertin: 14.4 ± 2.1 mmHg vs. 11.1 ± 1.0 mmHg (P = 0.003); KXA: 14.4 ± 1.0 mmHg vs. 11.3 ± 0.8 mmHg (P < 0.001)] and tonometry [avertin: 10.8 ± 1.4 mmHg vs. 7.4 ± 0.6 mmHg (P < 0.001); KXA: 11.9 ± 0.9 mmHg vs. 10.3 ± 1.7 mmHg (P = 0.283)]. However, treatment with KH7 in nonanesthetized mice showed a significant decrease in IOP measured by tonometry and compared with DMSO-treated animals [13.1 ± 2.6 mmHg vs. 15.6 ± 0.5 mmHg (P = 0.003)]. Both KH7- and DMSO-treated groups anesthetized with avertin showed increased corneal thickness, whereas KH7-treated mice anesthetized with KXA exhibited a shallower anterior chamber compared with untreated mice. KH7 decreased outflow facility by 85.1% in nonanesthetized, enucleated eyes (P < 0.003). CONCLUSIONS: Systemically administered DMSO and anesthesia have significant effects on anterior chamber characteristics, resulting in altered IOP readings measured by tonometry. In the presence of DMSO and anesthesia, tonometry IOP readings should be confirmed with direct cannulation.

Evaluation and comparison of xylazine hydrochloride and dexmedetomidine hydrochloride for the induction of emesis in cats: 47 cases (2007-2013).

OBJECTIVE: To evaluate and compare i.m. administration of xylazine hydrochloride and dexmedetomidine hydrochloride for the induction of emesis in cats. DESIGN: Retrospective case series. ANIMALS: 47 cats with a history of suspected ingestion of a toxic substance or foreign material between June 2007 and June 2013. PROCEDURES: Data collected for analysis from the medical records included signalment, drug dose and route of administration, whether a repeated dose of the emetic agent was administered, and outcome (emesis, yes or no). RESULTS: Cats in the 2 treatment groups did not differ with regard to age, sex, or breed distribution. The range of doses of xylazine administered i.m. was 0.36 to 0.64 mg/kg (0.16 to 0.29 mg/lb). The range of doses of dexmedetomidine administered i.m. was 6 to 18 µg/kg (2.7 to 8.2 µg/lb). A repeated dose of xylazine or dexmedetomidine was given to 3 and 1 cats, respectively. Emesis was successfully induced in 24 of the 47 (51.1%) cats. Nine of the 21 (43%) cats that received xylazine vomited and 15 of the 26 (58%) cats that received dexmedetomidine vomited. Percentage of cats that vomited after either drug administration did not differ significantly. CONCLUSIONS AND CLINICAL RELEVANCE: Following i.m. administration in cats, xylazine and dexmedetomidine were similarly effective for induction of emesis, indicating that dexmedetomidine is a comparable alternative to xylazine for this purpose. Prospective studies are needed to determine the optimal i.m. dose of dexmedetomidine for induction of emesis in cats.

Effect of analgesia and anti-inflammatory treatment on weight gain and milk intake of dairy calves after disbudding.

AIM: To assess the effect of analgesia at disbudding on weight gain and milk intake of dairy calves. METHODS: Four disbudding protocols were used on 3- to 6-week-old Friesian-Jersey calves. Farm staff disbudded 101 calves without sedation or local analgesia, of which 51 received 20 mg meloxicam S/C. Veterinary staff disbudded 101 calves with sedation and local analgesia, of which 51 also received 20 mg meloxicam S/C. Calves were weighed before disbudding, 15 and 30 days later, and individual milk consumption was recorded for 11 days. Daily weight gain and milk consumption were analysed using mixed models and ANOVA. RESULTS: From disbudding (Day 0) to Day 15 farmer-disbudded calves receiving meloxicam grew faster (0.65 kg/day) than calves without meloxicam (0.55 kg/day; p=0.011), but an interaction between operator and meloxicam treatment (p=0.056) meant that meloxicam treatment did not increase growth rates in veterinary-disbudded calves (0.63 vs. 0.64 kg/day; p=0.872). From Days 16-30 there was no significant effect of meloxicam on growth rate, but veterinarian-disbudded calves grew faster (0.76 kg/day) than farmer-disbudded calves (0.66 kg/day; p=0.034). Overall, for the first 30 days after disbudding, if meloxicam was not used', veterinarian-disbudded calves grew faster than farmer-disbudded calves (p=0.002). However if meloxicam was used at disbudding there was no difference in growth rate between veterinarian- and farmer-disbudded calves (p=0.878). Mean cumulative milk consumption for the 11 days after disbudding was greater for calves disbudded by veterinary staff than by farm staff (p<0.001), but there was no effect of meloxicam treatment (p=0.618) and no interaction with operator (p=0.86) on cumulative milk consumption. CONCLUSIONS: Three to 6-week-old dairy calves disbudded by farm staff with no analgesia grew significantly slower over the next 15 days than farmer-disbudded calves given meloxicam, and slower over the next 30 days than veterinarian-disbudded calves given xylazine and lignocaine. However addition of meloxicam to the latter protocol had no effect on growth rate. Milk intake was significantly higher for 11 days for veterinarian- compared with farmer-disbudded calves. CLINICAL RELEVANCE: This study adds to the evidence that analgesia during disbudding is beneficial for calf productivity as well as calf welfare.

Antiemetic efficacy of promethazine on xylazine-induced emesis in cats.

The prophylactic antiemetic effect of 3 dosages of promethazine injected into cats 1 h before administration of xylazine was compared with that of a saline solution. Prior treatment with 2 and 4 mg/kg of promethazine significantly reduced the frequency of emetic episodes. Promethazine may be used as a prophylactic antiemetic in cats treated with xylazine.

The effects of adding epinephrine or xylazine to lidocaine solution for lumbosacral epidural analgesia in fat-tailed sheep.

This blinded, randomised experimental study was designed to compare the analgesic effects of lumbosacral epidural administration of lidocaine-epinephrine or lidocaine-xylazine combinations in fat-tailed sheep. Nine healthy fat-tailed male lambs (mean ± s.d. age, 4.6 ± 0.4 months; weight, 24.6 kg ± 2.5 kg) were randomly allocated into four groups of six sheep: lidocaine 2% (LID), lidocaine-epinephrine 5 µg/mL (LIDEP), lidocaine-xylazine 0.05 mg/kg (LIDXY) or bupivacaine 0.5% (BUP). The onset and duration of flank, perineum and hindlimb anaesthesia and the onset and duration of hindlimb paralysis were recorded. Epidural administration of LID, LIDEP, LIDXY or BUP produced anaesthesia within 6.6 min, 7.6 min, 3.4 min and 8.4 min, respectively. The mean onset of anaesthesia in the LIDXY group was significantly shorter compared with the BUP group (p = 0.02). The mean duration of anaesthesia was 107.9 min, 190.4 min, 147.6 min and 169.7 min for LID, LIDEP, LIDXY and BUP, respectively. The onset of hindlimb paralysis was faster in the LIDXY group than in the BUP group; however, the duration of hindlimb paralysis was shorter in LIDXY compared with LIDEP. Epidural administration of LIDEP or LIDXY provides a comparable duration of local anaesthesia without any adverse effects in fat-tailed sheep. Epidural LIDXY did not appear to be advantageous over epidural LIDEP.

Eficiência do laser diodo 980 nm em comparação à da glicose a 75 por cento na oclusão de veias da orelha de coelhos / The efficiency of the diode laser 980 nm compared to glucose 75 percent in occlusion of the veins in rabbit ears

CONTEXTO: Por ser o laser um método novo no tratamento das varizes, há muitos mitos e dúvidas com relação à sua eficácia; assim, surgiu a necessidade de compará-lo a substância esclerosante mais utilizada em nosso meio (glicose hipertônica). OBJETIVO: Comparar a eficiência do laser diodo 980 nm à glicose 75 por cento na oclusão de veias em orelha de coelho. MÉTODOS: Ensaio aleatório em animais de laboratório por 21 dias. A amostra consistiu de orelhas de coelhos machos adultos. Grupo L (laser): 15 orelhas tratadas com laser; grupo G (glicose 75 por cento): 15 orelhas tratadas com glicose a 75 por cento. Variáveis primárias: veias esclerosadas e/ou ocluídas. Variáveis complementares: volume da substância administrada, complicações e peso. O tamanho da amostra foi estimado em 30 orelhas. Foi realizado o teste exato de Fisher associado ao Risco Relativo (RR), calculando-se o intervalo de confiança (IC) de 95 por cento para as variáveis acima. RESULTADOS: A incidência de esclerose ou oclusão venosa no grupo G foi de 53 por cento (8/15; IC95 por cento: 27-79) e no grupo L, 20 por cento (3/15; IC95 por cento: 4-49). O p bicaudal foi de 0,1281, o RR usando a aproximação de Katz foi de 2,66; IC95 por cento: 0,87-8,15. CONCLUSÃO: A eficiência do laser diodo 980 nm em comparação à da glicose 75 por cento na oclusão de veias para o modelo experimental estudado foi equivalente.

BACKGROUND: The laser is a new treatment to varicose veins and there is several myths and doubts in relation to its efficacy; then, there is the need to compare it with the most commonly sclerosing solution (hypertonic glucose) used in our specialty. OBJECTIVE: To compare the efficiency of the diode laser 980nm to the glucose 75 percent in the occlusion of veins from the ear of rabbits. METHODS: Aleatory trial in laboratory animals during 21 days. The sample consisted of ears from male adult rabbits. Group L (laser): 15 ears treated with laser; group G (glucose 75 percent): 15 ears treated with glucose 75 percent. Primary variables: sclerotic and/or occluded veins. Complementary variables: volume of the managed substance, complications and weight of rabbit. The sample size was estimated in 30 ears. The statistical analysis was carried out by Fisher''s exact test associated to the Relative Risk (RR), calculating the confidence interval of 95 percent for the mentioned variables. RESULTS: The incidence of sclerosis or venous occlusion in group G was 53 percent (8/15; 95 percentCI: 27-79) and in group L was 20 percent (3/15; 95 percent CI: 4-49). Two-tailed p was 0.1281, RR using the approximation of Katz was 2.66; 95 percentCI: 0.87-8.15. CONCLUSION: The efficiency of the diode laser 980 nm in comparison to glucose 75 percent in occlusion of veins in this experimental model was equivalent.

Electro-acupuncture reduces the need for additional anesthetics in experimental studies.

PURPOSE: To evaluate the possible beneficial effects of electro-acupuncture in rats subjected to ketamine/xylazine (KX) intra-peritoneal (i.p.) anesthesia. METHODS: Forty-eight male Wistar rats were distributed in four equal groups. All rats received i.p. injections of ketamine (90 mg/kg) +xylazine (10 mg/kg) anesthesia. Basal values group (control) rats (BV) received no additional treatment. The equivalent of the human right ST36 (Zusanli) and CV-12(Zhongwan) acupoints were chosen for needling and electrical stimulation. AC rats were needled with sterilized disposable stainless steel needles at right ST36 and CV12 acupoints; needles were retained for 30 minutes. EAC10 rats, after needle insertion as described, had electrodes connected to both needles and to an electro stimulator model NKL EL-608; pulsed square waves, 10 Hz, 10 mA, was applied for 30 minutes. EAC100 rats were submitted to EA as described. However, a greater frequency (100 Hz) was used. RESULTS: Thirty-seven rats remained under adequate anesthetic level during the experiment. However, maintenance anesthesia was required by 11 rats. Need for additional anesthesia decreased to 9.1% in EAC100 rats compared to BV (36.3%). CONCLUSION: Both the AC and the EAC10/100 prolong the anesthetic effect of the combination Ketamine-xylazine in rats, allowing longer duration of anesthesia with a lower dose of anesthetic, thereby reducing the occurrence of complications.

Electro-acupuncture reduces the need for additional anesthetics in experimental studies / Eletroacupuntura reduz a necessidade de doses adicionais de anestésicos em estudos experimentais

PURPOSE: To evaluate the possible beneficial effects of electro-acupuncture in rats subjected to ketamine/xylazine (KX) intra-peritoneal (i.p.) anesthesia. METHODS: Forty-eight male Wistar rats were distributed in four equal groups. All rats received i.p. injections of ketamine (90 mg/kg) +xylazine (10 mg/kg) anesthesia. Basal values group (control) rats (BV) received no additional treatment. The equivalent of the human right ST36 (Zusanli) and CV-12(Zhongwan) acupoints were chosen for needling and electrical stimulation. AC rats were needled with sterilized disposable stainless steel needles at right ST36 and CV12 acupoints; needles were retained for 30 minutes. EAC10 rats, after needle insertion as described, had electrodes connected to both needles and to an electro stimulator model NKL EL-608; pulsed square waves, 10 Hz, 10 mA, was applied for 30 minutes. EAC100 rats were submitted to EA as described. However, a greater frequency (100 Hz) was used. RESULTS: Thirty-seven rats remained under adequate anesthetic level during the experiment. However, maintenance anesthesia was required by 11 rats. Need for additional anesthesia decreased to 9.1 percent in EAC100 rats compared to BV (36.3 percent). CONCLUSION: Both the AC and the EAC10/100 prolong the anesthetic effect of the combination Ketamine-xylazine in rats, allowing longer duration of anesthesia with a lower dose of anesthetic, thereby reducing the occurrence of complications.

OBJETIVO: Avaliar os possíveis efeitos benéficos da eletroacupuntura em ratos submetidos à anestesia intraperitoneal (i.p.) com ketamina / xilazina. MÉTODOS: Quarenta e oito ratos Wistar foram randomizados em quatro grupos iguais. Todos os ratos receberam injeções i.p. de ketamina (90 mg / kg) + xilazina (10 mg / kg). Os ratos do grupo Valores Basais (controle - BV) não receberam nenhum tratamento adicional. Os acupontos equivalentes aos humanos E-36 (Zusanli) e VC-12 (Zhongwan) foram escolhidos para inserção de agulhas e estimulação elétrica. Os ratos do grupo AC foram estimulados com agulhas esterilizadas descartáveis, de aço inoxidável, nos acupontos E-36 direito e VC12. As agulhas foram mantidas por 30 minutos. Nos ratos do grupo EAC10, após agulhamento, como descrito, eletrodos foram conectados às agulhas e ao eletro-estimulador modelo NKL EL-608 e aplicadas ondas quadradas pulsantes, 10 Hz, 10 mA, por 30 minutos. Os ratos do grupo EAC100 foram submetidos à EA como descrito. No entanto, uma maior freqüência (100 Hz) foi utilizada. RESULTADOS: Trinta e sete ratos permaneceram no nível anestésico adequado durante o experimento. No entanto, a manutenção da anestesia foi se fez necessária em 11 animais. Nos ratos do grupo EAC100 a necessidade de anestesia complementar diminuiu para 9,1 por cento em comparação com ratos do grupo BV (36,3 por cento). CONCLUSÃO: Tanto a AC como a EAC10/100 prolongam o efeito anestésico da combinação ketamina-xilazina em ratos, permitindo maior duração da anestesia com menor dose de anestésico, reduzindo assim a ocorrência de complicações.

Physiologic effects of electroacupuncture combined with intramuscular administration of xylazine to provide analgesia in goats.

OBJECTIVE: To investigate physiologic effects of electroacupuncture (EA) combined with xylazine administration in goats. ANIMALS: 48 healthy crossbred goats. PROCEDURES: Goats were randomly allotted to 8 groups of 3 (nonpregnant and nonlactating) female goats and 3 male goats each. The 8 treatment groups were as follows: 1 EA group, 3 xylazine (0.1, 0.2, and 0.4 mg/kg, IM) groups, 3 EA plus xylazine (0.1, 0.2, and 0.4 mg/kg, IM) groups, and 1 control group. Electroacupuncture was performed for 90 minutes. Xylazine was administered 20 minutes after EA was performed. Pain threshold, heart rate, mean arterial pressure (MAP), respiration rate, and rectal temperature were observed at 0, 5, 25, 45, 65, and 85 minutes after xylazine administration. RESULTS: Xylazine administered at 0.4 mg/kg increased the pain threshold and reduced MAP. Xylazine administered at 0.1, 0.2, or 0.4 mg/kg reduced heart rate, respiration rate, and temperature. Electroacupuncture increased the pain threshold but had no effect on heart rate, MAP, respiratory rate, or rectal temperature. Pain threshold in goats that underwent EA plus xylazine administration was higher than in goats that received EA or xylazine alone. Electroacupuncture combined with xylazine at 0.1 mg/kg did not affect heart rate, MAP, respiratory rate, or rectal temperature. Pain threshold in goats that underwent EA plus xylazine administration at 0.1 mg/kg was higher than in goats given xylazine at 0.4 mg/kg alone. CONCLUSIONS AND CLINICAL RELEVANCE: Electroacupuncture combined with xylazine, even at 0.1 mg/kg, provided analgesia without significantly affecting cardiorespiratory parameters or rectal temperature in goats.

Antagonistic effects of yohimbine in pigs anaesthetised with tiletamine/zolazepam and xylazine.

Twelve healthy two-month-old Landrace x Yorkshire pigs of both sexes were randomly assigned to receive either tiletamine and xylazine (zx) or zolazepam and xylazine followed 20 minutes later by yohimbine (zxy). The pigs' scores for immobilisation and analgesia, and their rectal temperature, heart rate, respiration rate, pO(2), pCO(2), alkaline phosphatase, aspartate aminotransferase, glucose and total plasma proteins were determined before and five, 25, 45, 65 and 85 minutes after the administration of the tiletamine/zolazepam and xylazine. The mean total scores for immobilisation and analgesia of the zxy pigs were significantly lower than those of the zx pigs after 85 minutes. The mean rectal temperatures of the zxy pigs were significantly lower than those of zx pigs after 25, 45 and 65 minutes. The mean respiratory rates of the zx pigs were significantly lower than those of zxy pigs after five minutes. The mean pCO(2) of the zxy pigs were significantly lower than those of zx pigs five minutes after the administration of yohimbine. The mean glucose concentration of the zxy pigs were significantly lower than those of zx pigs after 65 and 85 minutes. The mean concentration total protein of the zxy pigs were significantly lower than those of zx pigs throughout the period of anaesthesia. Both groups became laterally recumbent within three minutes. When recovering from anaesthesia, the pigs treated with yohimbine took significantly less time to achieve sternal recumbency (mean [sd] 52.2 [8.9] v 76.2 [20.6] minutes) and less time to be able to stand (mean [sd] 77.0 [9.8] v 98.7 [15.8] minutes), and walk (mean [sd] 81.3 [11.3] v 110.8 [18.6] minutes).

Continuous infusion in adult females dogs submitted to ovariohysterectomy with midazolam-xylazine and/or medetomidine pre-treated with methotrimeprazine and buprenorphine

PURPOSE: To compare, by continuous infusion of ketamine or medetomidine combined to methotrimeprazine and buprenorphine, ketamine and midazolam, the degree of hypnosis, myorelaxation, anesthetic quality and surgical feasibility through evaluation of possible parametric alterations and recovery quality. METHODS: 20 healthy adult females dogs, aged 3 to 5 years, body weight between 7 and 15 kg, were assigned randomly and homogenously to 2 groups of 10 animals each (n=10), group 1 (G1) and group 2 (G2), respectively. Animals of G1 were subjected to a pre-treatment with intravenous 1.0 mg/kg methotrimeprazine and or 3ì/kg. After 15 minutes, a 5.0 mg/kg ketamine and 0.2 mg/kg midazolam were intravenously injected. Immediately after induction, an anesthetic combination of 0.4 mg/kg/h midazolam, 20 mg/kg/h ketamine and 1.0 mg/kg/h xylazine, was continuously and intravenously administered for 30 minutes. The same techniques were used in G2 except for the substitution of xylazine for 30ìg/kg/h medetomidine. RESULTS: In G1 there was a 1st and 2nd degree atrioventricular heart block, a longer recovery period and lower quality. In G2 a 1st degree atrioventricular heart block occurred but isolated and ephemeral. CONCLUSIONS: The continuous infusion method, besides reducing drugs utilization, prevented collateral effects allowing a more tranquil recovery with no excitations, both protocols permitted the surgical procedure (ovary-hysterectomy) bringing about a reduction in hypnosis and an accentuated myorelaxation. Xylazine and medetomidine showed a similar pharmacodynamic behavior but with different clinical aspects. The electrocardiographic alterations observed in G2 and in a lower degree in G1 must be well studied. Describers: dogs, ketamine, methotrimeprazine, medetomidine, midazolam and xylazine.

OBJETIVO: Comparar através de infusão contínua de xilazina ou medetomidina associada à metotrimeprazina e buprenorfina, cetamina e midazolam, o grau de hipnose, miorrelaxamento e qualidade anestésica e a viabilidade cirúrgica, avaliando eventuais alterações paramétricas e qualidade de recuperação. MÉTODOS: Foram utilizados 20 cães fêmeas, adultas, hígidas (3 a 5 anos de idade) com peso corporal entre 7 e 15 quilos, escolhidas e distribuídas aleatoriamente de forma homogênea em 2 grupos de 10 animais cada, (n=10) sendo estes designados por Grupo 1 (G1), e Grupo 2 (G 2). Em G1, os animais foram submetidos a um pré-tratamento com metotrimeprazina na dose de 1,0 mg/kg e buprenorfina na dose de 0,003mg/kg ou 3 µg/kg intravenoso. Decorridos 15 minutos, administrou-se cetamina na dose de 5,0 mg/kg e midazolam na dose de 0,2 mg/kg intravenoso. Imediatamente após a indução iniciou-se administração contínua, por um período de 30 minutos, da associação anestésica de midazolam 0,4 mg/kg/h, cetamina 20mg/kg/h e xilazina 1,0 mg/kg/h IV. Em G 2 utilizou-se a mesma técnica empregada em G1 substituindo-se, a xilazina pela medetomidina na dose de 30µg/kg/h. RESULTADOS: Verificou-se em G1 bloqueio átrio-ventricular de primeiro e segundo grau, período de recuperação mais longo além de menor qualidade. Em G 2 observou-se bloqueio átrio-ventricular de primeiro grau isolado e de ação fugaz. CONCLUSÕES: Ao se aplicar o método de infusão contínua, além da redução dos fármacos aplicados, evitaram-se efeitos colaterais permitindo uma recuperação mais tranqüila e isenta de excitações, ambos os protocolos permitiram a realização do ato cirúrgico (ovário-salpingo-histerectomia), causando uma redução da hipnose e um miorrelaxamento acentuado. A xilazina e a medetomidina apresentam um comportamento farmacodinâmico semelhante, porém com aspectos clínicos diferentes, as alterações eletrocardiográficas observadas em G 2 e em menor grau em G1 devem ser melhor estudadas.

Continuous infusion in adult females dogs submitted to ovariohysterectomy with midazolam-xylazine and/or medetomidine pre-treated with methotrimeprazine and buprenorphine.

PURPOSE: To compare, by continuous infusion of ketamine or medetomidine combined to methotrimeprazine and buprenorphine, ketamine and midazolam, the degree of hypnosis, myorelaxation, anesthetic quality and surgical feasibility through evaluation of possible parametric alterations and recovery quality. METHODS: 20 healthy adult females dogs, aged 3 to 5 years, body weight between 7 and 15 kg, were assigned randomly and homogenously to 2 groups of 10 animals each (n=10), group 1 (G1) and group 2 (G2), respectively. Animals of G1 were subjected to a pre-treatment with intravenous 1.0 mg/kg methotrimeprazine and or 3ì/kg. After 15 minutes, a 5.0 mg/kg ketamine and 0.2 mg/kg midazolam were intravenously injected. Immediately after induction, an anesthetic combination of 0.4 mg/kg/h midazolam, 20 mg/kg/h ketamine and 1.0 mg/kg/h xylazine, was continuously and intravenously administered for 30 minutes. The same techniques were used in G2 except for the substitution of xylazine for 30ìg/kg/h medetomidine. RESULTS: In G1 there was a 1st and 2nd degree atrioventricular heart block, a longer recovery period and lower quality. In G2 a 1st degree atrioventricular heart block occurred but isolated and ephemeral. CONCLUSIONS: The continuous infusion method, besides reducing drugs utilization, prevented collateral effects allowing a more tranquil recovery with no excitations, both protocols permitted the surgical procedure (ovary-hysterectomy) bringing about a reduction in hypnosis and an accentuated myorelaxation. Xylazine and medetomidine showed a similar pharmacodynamic behavior but with different clinical aspects. The electrocardiographic alterations observed in G2 and in a lower degree in G1 must be well studied. Describers: dogs, ketamine, methotrimeprazine, medetomidine, midazolam and xylazine.

Anti-emetic effect of oculo-acupuncture on dogs with xylazine induced vomiting.

The present study was conducted in order to clarify the anti-emetic effect of oculo-acupuncture (OA) on dogs with xylazine-induced vomiting, and also to compare the anti-emetic effect of OA and body acupuncture (AP). Twelve dogs induced to vomit by xylazine were selected from total 29 mongrel dogs in preliminary experiment and were used as subjects in this study. This study was comprised of two experiments. In experiment 1, the anti-emetic effects of OA on dogs were examined in the stomach/spleen region (experimental group I), the zhongjiao region (experimental group II), and the stomach/spleen region plus the zhongjiao region (experimental group III) using 12 dogs induced to vomit for one week interval repeatedly. On the other hand, needle acupuncture (AP) (BL20 + BL21, experimental group A) and OA (stomach/spleen and zhong jiao regions) combined with needle AP (BL20 + BL21) (experimental group B) were examined using 6 vomiting dogs, for one week interval repeatedly in experiment 2. As a result, the vomiting rates of experimental group I (50%, p < 0.05), experimental group II (58.3%) and experimental group III (41.6%, p < 0.01) were lower than that of control (100%), respectively in experiment 1. The vomiting rates of both experimental group A (50%, p < 0.05) and experimental group B (50%, p < 0.05) were lower than that of control (100%) in experiment 2. The starting vomiting time in experimental groups was similar to that of the control groups in experiment 1 and 2. This study demonstrated that OA had anti-emetic effects on dogs with xylazine-induced vomiting and OA in the stomach/spleen region plus the zhongjiao region was the most effective in anti-emesis among the experimental groups. In addition, body AP and OA combined with body AP had a similar anti-emetic effect on dogs with xylazine-induced vomiting.

Ischemic brain damage after ketamine and xylazine treatment in a young laboratory monkey (Macaca fascicularis).

After a 4-year-old female laboratory cynomolgus monkey manifested neurological abnormalities, including tetanic spasm, after intramuscular injection of 20 mg/kg ketamine, we administered 2 mg/kg xylazine in an attempt to control the seizure. However, the animal continued to display opisthotonus, nystagmus, and symptomatic epilepsia. Analysis of blood chemistry revealed a dramatically increased creatine phosphokinase level. Abnormal histopathological findings included acute neuronal necrosis or glial reaction or both in the cerebral cortex, nucleus lentiformis, hippocampus, cerebellar cortex and nucleus, and medulla oblongata; severe myocardial hemorrhagic necrosis; and hepatic subcapsular hematoma. Although the mechanism of this neuronal damage has not been clarified, it may be attributable to an ischemic condition in the brain, probably due to temporal cardiac arrest or hemorrhagic change in the liver and heart, with subsequent decreased blood pressure, after ketamine and/or xylazine treatment. Because both drugs often are used as general anesthetics in veterinary medicine, attention should be paid to this rare case with neural damage.

Efeitos hemogasométricos da xilazina e da romifidina em cabras tratadas por ioimbina / Haemogasometric effects of xylazine and romifidine in goats treated with yohimbine

Estudaram-se as alterações produzidas por doses equipotentes de xilazina e romifidina e os efeitos da administração subseqüente de ioimbina em oito cabras mestiças. Respeitou-se um intervalo de sete dias entre os seguintes tratamentos: A- 250µg/kg/IM de xilazina e 0,1ml/kg/IV de solução fisiológica, B- 250µg/kg/IM de xilazina e 250µg/kg/IV de ioimbina, C- 25µg/kg/IM de romifidina e 0,1ml/kg/IV de solução fisiológica, D- 25µg/kg/IM de romifidina e 250µg/kg/IV de ioimbina. Foram mensurados a freqüência respiratória, o pH, as pressões parciais de oxigênio e dióxido de carbono, a concentração de íon bicarbonato, o excesso de bases e a saturação de oxigênio no sangue arterial. Utilizou-se um delineamento experimental crossover, e as médias foram comparadas pelo teste Duncan (Pmenor ou igual a 0,05). Xilazina e romifidina reduziram a pressão arterial de oxigênio e aumentaram a pressão arterial de dióxido de carbono. A ioimbina reverteu os efeitos da xilazina e da romifidina sobre as pressões parciais de oxigênio e dióxido de carbono no sangue arterial.