Yohimbine antagonizes the anaesthetic effects of ketamine-xylazine in captive Indian wild felids

Objective: To determine the effectiveness of yohimbine as an antagonist of ketamine-xylazine anaesthesia in captive Asiatic lions (Panthera leo persica), tigers (Panthera tigris) and leopards (Panthera pardus). Study design: Prospective clinical trial. Animals: Fifty-two healthy adult lions, 55 adult leopards and 16 adult male tigers. Methods: Captive wild felids in Indian zoos were anaesthetized with a combination of ketamine (2.2-2.6 mg kg−1) and xylazine (1.1-1.3 mg kg−1) using a dart propelled from a blowpipe. Time to onset of anaesthesia, lateral recumbency and induction time were measured, and physiological variables (respiration, heart rate and rectal temperature) were recorded once after the onset of complete anaesthesia. Anaesthesia was antagonized at various time periods with an intravenous administration of either 0.1 or 0.15 mg kg−1 yohimbine. Onset of arousal and time to complete anaesthetic recovery were recorded. Results: A total of 123 immobilizations were conducted between 2000 and 2005. Anaesthetic induction was achieved in 15-25 minutes in all animals. Incidents of sudden recovery or life-threatening effects associated with immobilizations were not observed. Yohimbine effectively antagonized anaesthesia in all animals within 10 minutes without any excitatory behaviour compared to control animals. No adverse reactions/side effects to yohimbine were recorded except that a few leopards exhibited seizure-like signs for a short period immediately after yohimbine administration. The duration of anaesthesia had no significant effect on the recovery time in any of the animals. Conclusion and clinical relevance: Yohimbine antagonized the xylazine portion of ketamine-xylazine anaesthesia and thereby hastened recovery from anaesthesia in Asiatic lions, tigers and leopards

Seasonal variations in semen characteristics, semen cryopreservation, estrus synchronization, and successful artificial insemination in the spotted deer (Axis axis)

Ten adult male spotted deer were monitored over a 2-year interval to determine seasonal variations in testicular size, semen characteristics and serum testosterone concentrations, and to determine if there was an association between season and type of antler. Mean (±S.E.M.) testicular volume (118.8 ± 4.6 cm3), serum testosterone concentration (1.2 ± 0.1 ng/mL), semen volume (4.1 ± 0.6 mL), sperm concentration (338.3 ± 24.9 × 106 mL−1), percentage of morphologically normal sperm (79.1 ± 2.8%), and percentage of motile sperm (66.5 ± 1.5%) were higher (P < 0.05) in hard antler deer (peaked from March to May) than in deer with velvet antlers or in deer in which the antler has been shed. Thus, March-May was considered the physiologic breeding season for these deer; at this time, all stags had hard antlers. Furthermore, a Tris-citrate-based semen extender containing 4% glycerol and 20% egg-yolk was adequate for cryopreservation of semen. Estrus was induced with an implant containing norgestomet, timed transcervical AI was done with fresh semen, and 3 of 10 females were pregnant at 60 days, with fawns born 120 (premature), 240 and 243 days after AI. These results were considered a model for the use of assisted reproductive techniques to conserve other critically endangered deer species of India

Tolazoline antagonises ketamine-xylazine anaesthesia in an endangered Black buck (Antilope cervicapra)

Seventy-seven anaesthetic events were carried out in 22 captive adult Black bucks (Antilope cervicapra) of either sex with a combination of 2 mg kg<SUP>&#8722;1</SUP> ketamine hydrochloride with 0.25 mg kg<SUP>&#8722;1</SUP> xylazine hydrochloride using a dart delivered from a blowpipe. Randomised anaesthetised animals received an intravenous injection of either yohimbine hydrochloride (0.125 or 0.25 mg kg<SUP>&#8722;1</SUP>) or tolazoline hydrochloride (1 or 2 mg kg<SUP>&#8722;1</SUP>) after 30-40 min of anaesthesia to antagonise the anaesthetic effects. Ketamine-xylazine induced smooth, rapid and reliable anaesthesia within 5-7 min of darting with no clinical adverse effects and causalities during or post-anaesthesia. Yohimbine failed to antagonise the anaesthetic effects of ketamine-xylazine in the Black buck. On the other hand, tolazoline was found to be very effective in hastening recovery in dose-dependent manner within 0.5-1.5 min. This study documents the first report of ketamine-xylazine anaesthesia and its antagonism by tolazoline in captive Black buck

Anesthesia induced by administration of xylazine hydrochloride alone or in combination with ketamine hydrochloride and reversal by administration of yohimbine hydrochloride in captive Axis deer (Axis axis)

Objective- To determine the anesthetic dose and cardiopulmonary effects of xylazine hydrochloride when used alone or in combination with ketamine hydrochloride and evaluate the efficacy of yohimbine hydrochloride to reverse anesthetic effects in captive Axis deer. Animals- 35 adult (10 males and 25 females) Axis deer (Axis axis). Procedures- All deer were anesthetized by IM administration of xylazine (3.5 mg/kg; experiment 1), a combination of ketamine and xylazine (1.25 and 1.5 mg/kg, respectively; experiment 2), or another combination of ketamine and xylazine (2.5 and 0.5 mg/kg, respectively; experiment 3). In addition, female deer were also anesthetized by IM administration of a third combination of ketamine and xylazine (1.5 and 1 mg/kg, respectively; experiment 4). Ten to 40 minutes after induction, anesthesia was reversed by IV administration of yohimbine (5, 8, or 10 mg). Results- In male deer, experiment 3 yielded the most rapid induction of anesthesia. In females, experiment 4 yielded the best induction of anesthesia without adverse effects. All doses of yohimbine reversed anesthesia. Duration of anesthesia before administration of yohimbine had no effect on recovery time. Conclusions and Clinical Relevance- A combination of ketamine and xylazine can be used to induce anesthesia in Axis deer. Furthermore, anesthetic effects can be reversed by administration of yohimbine

Ejaculate characteristics, short-term semen storage and successful artificial insemination following synchronisation of oestrus in the Indian blackbuck antelope (Antilope cervicapra)

The blackbuck (Antilope cervicapra) is a small (20-30 kg) Indian antelope that is listed on Schedule I of the Indian Wildlife Protection Act, 1972. Studies were undertaken to develop assisted reproductive technologies, such as synchronisation of oestrus and non-surgical AI, to support the conservation and genetic management of this Indian antelope. Semen characteristics, testosterone levels and the feasibility of short-term cold storage of semen were investigated. Furthermore, different oestrous synchronisation protocols (norgestomet implants and prostaglandin injections) were evaluated for successful AI, defined as the birth of live young. Norgestomet ear implants and i.m. administration of pregnant mare's serum gonadotropin (PMSG) resulted in successful pregnancies in two of five inseminated females, but both had twin pregnancies that were delivered prematurely. In contrast, two injections of prostaglandin 11 days apart were effective in synchronising oestrus in the blackbuck. Transcervical AI in oestrous-synchronised animals 72 and 96 h after the second prostaglandin injection resulted in successful pregnancies in four of six inseminated females (67%) and resulted in the delivery of three live fawns. These studies demonstrate the potential application of AI technology for the conservation of endangered ungulates. To our knowledge, this is the first report regarding the synchronisation of oestrus and successful non-surgical AI in blackbuck

Conservation of wild animals by assisted reproduction and molecular marker technology

710-723<span style="font-size:14.0pt;line-height: 115%;font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" mso-ansi-language:en-in;mso-fareast-language:en-in;mso-bidi-language:hi"="" lang="EN-IN">Wild animals are an integral component of the ecosystem. Their decimation due to abrupt natural calamities or due to gradual human intervention would be disastrous to the ecosystem and would alter the balance in nature between various biotic components. Such an imbalance could have an adverse effect on the ecosystem. Therefore, there is an urgent need to put an end to the ever increasing list of endangered species by undertaking both in situ and ex situ conservation using tools of modern biology, to ascertain the degree of genetic variation and reproductive competence in these animals. This review highlights the development and use of molecular markers such as microsatellites, minisatellites, mitochondrial control region, cytochrome b and MHC loci to assess the genetic variation in various Indian wild animals such as the lion, tiger, leopard and deer. The review also presents data on the semen profile of the big cats of India. Reproductive technologies such as cryopreservation of semen and artificial insemination in big cats are also highlighted.</span