Xylazine hydrochloride-ketamine hydrochloride immobilization of free-living red foxes (Vulpes vulpes) in Spain.

A combination of xylazine hydrochloride-ketamine hydrochloride was used to immobilize 83 wild red foxes (Vulpes vulpes) (15 pups and 68 adults) at Do?ana National Park (Spain). Mean ketamine hydrochloride doses were 17.1 mg/kg (SE = 1.53) and 12.3 mg/kg (SE = 0.4) for pups and adults, respectively, and mean xylazine hydrochloride doses for the same groups were 6.2 mg/kg (SE = 0.63) and 4.7 mg/kg (SE = 0.14), respectively. Mean induction times and first reaction times were 1.6 minutes and 22.5 minutes for pups and 3.8 minutes and 39.4 minutes for adults, respectively. Recommended doses for wild adult foxes of unknown weight are 75 mg of ketamine hydrochloride and 20 mg of xylazine hydrochloride.     

Immobilization of fishers (Martes pennanti) with ketamine hydrochloride and xylazine hydrochloride

A combination of 100 mg ketamine hydrochloride (KH) and 20 mg xylazine hydrochloride (XH) was used to immobilize fishers (Martes pennanti). Four adult males were intramuscularly injected a total of five times at dosages between 22.4 to 29.0 mg/kg KH and 4.1 to 6.6 mg/kg XH. Mean (+/- SE) induction time and arousal time were 3.3 +/- 0.5 min and 76.8 +/- 12.1 min, respectively. Respiration, heart rate, and body temperature in response to sedation appeared normal. A 5:1 mixture of KH-XH appears to be a safe immobilizing agent for fishers.     

Use of Ketamine hydrochloride and xylazine hydrochloride to immobilize black bears (Ursus americanus).

Ketamine hydrochloride (KH) and xylazine hydrochloride (XH) used in combination (KH-XH) were effective immobilants for captive and wild black bears (Ursus americanus). Single intramuscular injections of 1.5-17.1 mg of KH per kg body weight combined in an approximate ratio of 2:1 with 0.9-10.0 mg of XH per kg body weight immobilized bears for 1.5-197 min. Dosages most frequently used were 4.5-9 mg KH/kg with 2-4.5 mg XH kg. Supplemental administrations maintained tractability for up to 31 h. Immobilization was characterized by smooth induction, relaxed muscles, occasional groaning and vomition, no eye closure, no defecation, and a smooth recovery phase of variable length. Male and female bears responded similarly to KH-XH. Induction times for small bears (less than or equal to 25 kg) were shorter than for larger bears.     

Immobilization of free-ranging African lions (Panthera leo) with a combination of xylazine hydrochloride and ketamine hydrochloride

The combination of 55 mg/ml xylazine hydrochloride and 200 mg/ml ketamine hydrochloride was effective for immobilizing African lions in Tanzania. Nineteen adult females were given between 55 and 110 mg xylazine hydrochloride in the first dart. Initial doses of 110 mg xylazine hydrochloride and 450 mg ketamine hydrochloride equivalent to greater than 0.9 mg/kg xylazine hydrochloride were most effective in achieving rapid immobilization. Lower doses of xylazine hydrochloride required supplementation with ketamine hydrochloride. These doses could be delivered easily in 3-ml darts. The use of lightweight darts and a blowgun was found to be useful as a supplement to longer range dart projector systems since many animals could be approached at short range.     

Antagonism of xylazine hydrochloride with yohimbine hydrochloride and 4-aminopyridine in captive wapiti

Eight captive wapiti (Cervus elaphus nelsoni) were injected with xylazine hydrochloride on two occasions during March and April 1984. Animals were grouped into a modified Latin square design and were given either successive injections of yohimbine hydrochloride and 4-aminopyridine (4-AP) to antagonize the sedative effects of xylazine hydrochloride or permitted an unantagonized recovery. Induction times ranged from 3 to 26 min with excited and wild animals requiring a supplementary dose. Time until walking was significantly (P less than 0.005) shorter in the group given successive injections (given i.v.) of the reversal drugs yohimbine hydrochloride (0.15 mg/kg) and 4-AP (0.30 mg/kg) than those animals during unantagonized recoveries. Marked increase in heart rate and respiratory rate were observed in animals within 3 min after successive injections of yohimbine hydrochloride and 4-AP. There was no occurrence of convulsions and animals did not relapse to profound sedation. Slight muscle tremors were observed in one animal which received a dose of 0.35 mg/kg of 4-AP. This drug combination can reduce markedly the duration of recovery from xylazine hydrochloride-induced sedation in wapiti.     

Capture and immobilization of wild brown palm civets in Western Ghats

A mixture of 15 mg/kg body weight ketamine hydrochloride (KE) and 1.5 mg/kg body weight xylazine hydrochloride (XY) was used to successfully immobilize free-ranging brown palm civets (Paradoxurus jerdoni). Between March 1998 and June 1999, 10 immobilizations of 7 individuals were carried out in tropical rainforests of the Kalakad-Mundanthurai Tiger Reserve (India). Five males and two females were captured in Havahart live traps, using banana as bait. The mean dosage for the animals, whose weight (mean +/- SD) was 2.4 kg +/- 0.8 was 36.0 +/- 11.0 mg KE and 3.7 +/- 1.1 mg XY, administered intramuscularly. Mean time for lateral recumbency was 6.1 +/- 3.78 min (n = 10) and the mean time taken for complete recovery was 84.9 +/- 28.8 min (n = 9). Recovery was gradual and no fatalities or injuries occurred during the operation. The drug combination used was effective and has the potential for immobilizing other viverrids.     

Evaluation of a combination of tiletamine and zolazepam as an anesthetic for laboratory rodents

A combination of equal parts of tiletamine hydrochloride and zolazepam hydrochloride was evaluated as an injectable anesthetic for rats, mice, and hamsters. The drug produced satisfactory anesthesia and analgesia in rats when given either intraperitoneally or intramuscularly at concentrations of 20 or 40 mg/kg body weight. The length of anesthesia was dose dependent and was somewhat longer in females as compared to males, and inbreds compared to outbreds. Incisions through the peritoneum of anesthetized rats evoked little or no response, whereas cervical skin incisions evoked a slight response in many rats. Anesthesia without analgesia occurred in mice at dosages of 80 mg/kg body weight and higher, however, many animals developed respiratory distress and died at dosages of 100 to 160 mg/kg body weight. In hamsters, anesthesia but not analgesia occurred at drug concentrations of 50 to 80 mg/kg body weight. It was concluded that a tiletamine and zolazepam combination was an effective anesthetic for rats, but not for mice or hamsters.     

Effect of caffeine sodium benzoate, ketamine hydrochloride, and yohimbine hydrochloride on xylazine hydrochloride-induced anorexia in white-tailed deer

Fifteen male white-tailed deer (Odocoileus virginianus) were administered xylazine hydrochloride (1 mg/kg BW i.m.), xylazine hydrochloride (1 mg/kg i.m.) followed by caffeine sodium benzoate (10 mg/kg i.m.), xylazine hydrochloride (0.5 mg/kg i.m.) and ketamine hydrochloride (4.5 mg/kg i.m.), and xylazine hydrochloride (1 mg/kg i.m.) followed by yohimbine hydrochloride (0.125 mg/kg i.m.), in a Latin Square design. Mean dry matter intake (DMI) for 4 days pre-treatment was compared to each of 4 days post-treatment. A significant (P less than 0.01) decrease in DMI was found only on the first day following treatment for each of the four drug combinations. The percent decreases in DMI on the first 24-hr period after immobilization were: xylazine hydrochloride 47%, xylazine hydrochloride/caffeine sodium benzoate 36%, xylazine hydrochloride/yohimbine hydrochloride 36%, and xylazine hydrochloride/ketamine hydrochloride 31%. The xylazine hydrochloride/ketamine hydrochloride combination was found to be insufficient to adequately sedate the deer. The use of caffeine or yohimbine hydrochloride is recommended to reduce recumbency time, but offers no improvement in xylazine hydrochloride-induced anorexia.     

Immobilization of white-tailed deer with xylazine hydrochloride and ketamine hydrochloride and antagonism by tolazoline hydrochloride

Fourteen penned and 17 free-ranging white-tailed deer (Odocoileus virginianus Rafinesque) were singularly or repeatedly immobilized with 100 mg xylazine hydrochloride (HCl) and 300 mg ketamine HCl. The mean times from intravenous injection to ambulation for 1.0, 2.0, and 4.0 mg/kg body weight doses of tolazoline HCl were 13.5, 10.5, and 9.2 min. Deer not receiving tolazoline HCl recovered in an average of 168 min. Heart rates significantly (P less than 0.001) increased from 47 to 83 beats/min after tolazoline HCl administration, representing a return to normal rate. Tolazoline HCl had no effect on respiratory rate. A total of 85 reversals with tolazoline HCl resulted in no apparent adverse reactions.     

Yohimbine reversal of ketamine-xylazine immobilization of raccoons (Procyon lotor)

Six adult raccoons (Procyon lotor) were sedated with a combination of ketamine hydrochloride (KH) at 10 mg/kg body weight and xylazine hydrochloride (XH) at 2 mg/kg body weight intramuscularly (i.m.). Twenty min after the KH-XH combination was given, yohimbine hydrochloride (YH) at either 0.1 mg/kg (Trial 1) or 0.2 mg/kg (Trial 2) body weight or a saline control (Trial 3) was administered intravenously (i.v.). The time to arousal, time to sternal recumbency and time to walking were recorded. These times were significantly shortened after YH administration [e.g., mean time to walking (MTW) at 0.2 mg/kg YH = 23.7 min] as compared to the saline controls (MTW = 108.8 min). Heart and respiratory rates both increased after YH administration, while body temperature remained constant. A fourth trial was performed using a higher ratio of KH to XH (45:1 rather than 5:1) to mimic sedation as performed in the field. The mean time to arousal (MTA) and MTW in this trial (1.3 and 23.7 min, respectively) were significantly shorter than controls and similar to YH trials performed after immobilization with 5:1 KH-XH. Yohimbine hydrochloride may be useful in field studies that require sedation of raccoons using KH-XH combinations.     

Antagonism of xylazine hydrochloride-ketamine hydrochloride immobilization in guineafowl (Numida meleagris) by yohimbine hydrochloride

The mean time to arousal (MTA), the mean time to sternal recumbency (MTSR) and the mean time to walking (MTW) were measured in 10 adult guineafowl (Numida meleagris) immobilized with a combination of xylazine hydrochloride (1 mg/kg) and ketamine hydrochloride (25 mg/kg). Yohimbine hydrochloride, given intravenously (1 mg/kg) at 40 min after the injection of the xylazine-ketamine, significantly shortened the MTA, the MTSR and the MTW compared to saline controls. Increasing the dosage of yohimbine to 2.5 mg/kg did not shorten recovery when compared to the lower dosage. No adverse effects were noted at either dosage of yohimbine. Yohimbine appeared to be a safe and effective antagonist of xylazine-ketamine immobilization in guineafowl and may prove useful in other avian species to produce more rapid recovery from xylazine-ketamine immobilization, xylazine sedation or xylazine overdosage.     

Immobilization of wild dogs (Lycaon pictus) with a tiletamine hydrochloride/zolazepam hydrochloride combination and subsequent evaluation of selected blood chemistry parameters

A tiletamine hydrochloride/zolazepam hydrochloride combination was used successfully to immobilize captive untamed wild dogs (Lycaon pictus) (n = 16) at dosage rates ranging from 2.3 to 32.3 mg/kg. Animals remained immobilized for periods ranging from 35 min to 24 hr 14 min. There was a significant positive correlation (r = 0.85, P less than 0.01) between dosage rate and the time immobilized. Profuse salivation and intermittent mild myoclonal contractions were observed in some wild dogs. Mildly reduced partial oxygen and carbon dioxide pressures as well as reduced concentrations of bicarbonate were observed in arterial blood at 10 and 20 min after administration of the drug. Serum concentrations of sodium, potassium, chloride, phosphorus, calcium, magnesium, urea, creatinine, glucose, proteins, albumin, gammaglutamyltransferase, creatinine kinase, aspartate transaminase, alkaline phosphatase, lactate dehydrogenase, insulin, cortisol and thyroxine are presented. These concentrations were found to be in agreement with values previously reported for wild dogs.     

A comparison of carfentanil/xylazine and Telazol/xylazine for immobilization of white-tailed deer

October 2001 to January 2002, captive free-ranging white-tailed deer (Odocoileus virginianus) were immobilized with a combination of carfentanil citrate and xylazine hydrochloride. From this study, we selected a dose of carfentanil/xylazine for the purpose of comparing immobilization parameters and physiologic effects with those of a combination of tiletamine and zolazepam (Telazol) and xylazine. Animals were initially given intramuscular injections of 10 mg xylazine and one of four doses of carfentanil (i.e., 0.5, 1.0, 1.5, and 2.0 mg). A carfentanil dose of 1.2 mg (x +/- SD = 23.5 +/- 3.2 microg/kg) and 10 mg xylazine (0.2 +/- 0.03 mg/kg) were selected, based on induction times and previously published reports, to compare with a combination of 230 mg of Telazol (4.5 +/- 0.6 mg/kg) and 120 mg xylazine (2.3 +/- 0.3 mg/kg). Time to first observable drug effects and to induction were significantly longer for deer treated with carfentanil/xylazine than with Telazol/xylazine (P < 0.01). Hyperthermia was common in deer immobilized with carfentanil/xylazine, but heart rate, respiration rate, and hemoglobin saturation were within acceptable levels. Degree of anesthesia of deer immobilized with Telazol/xylazine was superior to deer immobilized with carfentanil/xylazine. The combination of 120 mg of naltrexone hydrochloride and 6.5 mg of yohimbine hydrochloride provided rapid and complete reversal (1.9 +/- 1.1 min) of carfentanil/xylazine immobilization. Animals immobilized with Telazol/xylazine had long recovery times with occasional resedation after antagonism with 6.5 mg of yohimbine. The combination of carfentanil and xylazine at the doses tested did not provide reliable induction or immobilization of white-tailel (leer even though drug reversal was rapid and safe using naltrexone and yohimbine.     

Cytotoxic effects of emetine hydrochloride in the kidney of Long-Evans rats

Emetine hydrochloride has been used to study its effects in the rat kidney, Sublethal doses of the drug at 10.0 mg/kg body weight of the animal were administered at 12 and 24 h intervals. Certain morphological changes occurred within the kidney. These changes involved the formation of vacuoles, swelling of mitochondria, disruption of basal membranes, deterioration of red blood cells, production of convoluted membranes and fibril-like structures. The earliest changes were observed 12 h after treatment with the drug.     

Immobilization with a single dose of ketamine hydrochloride and a combination of xylazine hydrochloride-ketamine hydrochloride and antagonism by yohimbine hydrochloride in the Japanese monkey (Macaca fuscata)

Forty-nine free-ranging Japanese monkeys (Macaca fuscata) were immobilized with 4.3–15.6 mg/kg (mean±S.D.=10.0±2.5 mg/kg) of ketamine hydrochloride (HCl), and 27 Japanese monkeys kept in enclosures were immobilized with a combination of 0.8–1.4 mg/kg (1.0±0.2 mg/kg) of xylazine HCl and 4.0–7.1 mg/kg (5.0±0.6 mg/kg) of ketamine HCl. In the xylazine HCl-ketamine HCl combination, good myorelaxation was induced. The mean induction times for the single dosage of ketamine HCl and the xylazine HCl-ketamine HCl combination were 2.8±1.5 min and 6.9±4.4 min, respectively. The mean immobilization times with the single dosage of ketamine HCl and the xylazine HCl-ketamine HCl combination were 39.3±16.5 min and 58.8±34.2 min, respectively. A half dose of ketamine HCl in combination with xylazine HCl could also immobilize Japanese monkeys successfully. Administrations of 0.5 mg/kg i.v. and 1.0 mg/kg i.m. of yohimbine HCl as an antagonist to xylazine HCl at 30 min after the induction reduced the immobilization time to 31.4±0.5 min and 49.0±22.1 min, respectively. Yohimbine HCl appears to be an effective antagonist to combination anesthesia by xylazine HCl-ketamine HCl in the Japanese monkey.     

Use of Telazol to immobilize female northern sea lions (Eumetopias jubatus) in Alaska

Twenty-nine female northern sea lions (Eumetopias jubatus) were immobilized using Telazol in dosages ranging from 1.8 to 8.1 mg/kg. Best results were achieved with Telazol dosages ranging between 1.8 and 2.5 mg/kg which resulted in smooth induction and recovery. Optimal injection location was in the muscle mass of the lower back and hip. Dosages greater than 3.5 mg/kg resulted in a tendency toward hypothermia. Six mortalities occurred which were partially caused by the location of drug injection and perhaps the high dosage.     

Field immobilization of American martens (Martes americana) and short-tailed weasels (Mustela erminea).

Ketamine hydrochloride (KH) and a 5:1 combination of KH and xylazine hydrochloride (XH) were used successfully to immobilize short-tailed weasels (Mustela erminea) and American martens (Martes americana), respectively. Four adult male martens were intramuscularly injected with 30 to 82 mg/kg KH and 8.0 to 16.4 mg/kg XH. Three adult male short-tailed weasels were intramuscularly injected with 20.8 to 42.1 mg/kg KH. Mean (+/- SE) induction times for martens and short-tailed weasels were 1.8 +/- 0.2 min and 46 +/- 4.1 sec, respectively; recovery times were 100.4 +/- 19.3 min and 97.9 +/- 6.3 min, respectively. Heart rate was relatively constant among martens; however, respiration varied widely (21 to 122 breaths per minute). Marten body temperature decreased between 0 and 20 min post-recumbency. Short-tailed weasel heart rate and respiration decreased in response to sedation until slightly before arousal. Body temperature stabilized by 20 min post-recumbency. Two short-tailed weasels tremored slightly within 10 min of arousal. I conclude that KH and KH/XH are safe immobilizing agents for martens and short-tailed weasels, respectively.     

Effects of eflornithine hydrochloride (DFMO) on fetal development in rats and rabbits

Eflornithine hydrochloride (DFMO) is a highly selective, enzyme-activated, irreversible inhibitor of the enzyme L-ornithine decarboxylase (ODC). Because of its role in the biosynthetic pathway of polyamines, ODC is essential for the growth and development of newly implanted embryonic tissue. In order to assess its effect on embryonic growth and fetal development, at various stages of gestation, DFMO was administered in the drinking water to pregnant rats and rabbits at several concentrations (from 0.03% to 3.0%) and times (from days 7, 10, or 11 through days 18 or 19). Rats were killed on day 21 and rabbits on day 29 of pregnancy (day 1 = day of insemination), and the implantations and fetuses were examined. At a concentration of 1.0% (approximately 1,270 mg/kg/day) in rats and 3.0% (approximately 915 mg/kg/day) in rabbits, maternal food and water consumption and body weight gain were significantly reduced during the treatment period, and all implantations were aborted or resorbed. At lower doses (approximately 200-600 mg/kg/day) fetuses survived to term, though in reduced numbers, and a marked reduction in average fetal weight was seen. At levels of 60 mg/kg/day or lower, there were no deleterious effects to the dams or their offspring. Few malformations were detected at any dose level by gross teratologic examination; nor were any considered to have been drug induced because of their sporadic incidence. The embryotoxicity and severe growth retardation demonstrated by these studies verify that adequate polyamine levels are essential for normal embryonic and fetal development.     

Liposome-encapsulated oxymorphone hydrochloride provides prolonged relief of postsurgical visceral pain in rats

Adequate pain control is necessary for optimal postsurgical recovery and humane treatment of laboratory and companion animals. Opioid drugs are currently the most potent analgesic agents available in human and veterinary medicine. Long-acting formulations of opioid drugs confer several important advantages over standard pharmaceutical preparations, especially for use in animals. A long-acting formulation of oxymorphone hydrochloride was produced by encapsulation into liposomes. Liposome-encapsulated (LE) oxymorphone was tested in a rat model of visceral postoperative pain. Rats were given one subcutaneous injection of LE oxymorphone (1.2 or 1.6 mg/kg of body weight) or standard oxymorphone (0.3 mg/kg) at the time of intestinal transection or resection. A single administration of LE oxymorphone hydrochloride was as effective for relief of postoperative pain in rats (P = 0.18), as were multiple (q4 h or q8 h) injections of 0.3 mg/kg of the standard pharmaceutical preparation. The rats given LE oxymorphone prior to intestinal resection also had significantly higher body weight at three and seven days after surgery than did rats that were given standard oxymorphone. In conclusion, LE oxymorphone was effective in treating visceral pain associated with intestinal surgery in rats. On the basis of body weight gain, rats treated with LE oxymorphone had improved recovery outcome, compared with rats treated with repeated injections of standard oxymorphone.     

Ketamine hydrochloride and xylazine hydrochloride anaesthesia in the golden hamster (Mesocricetus auratus)

The combination ketamine-xylazine was assessed as a surgical anaesthetic in the golden hamster. Several dose levels and routes of injection were evaluated. It was determined that 50-200 mg/kg bodyweight of ketamine with 10 mg/kg body weight of xylazine, when given by intraperitoneal injection, was a satisfactory general anaesthetic.