What is Xylazine
For Use in Horses and Cervidae (Fallow Deer, Mule Deer, Sika Deer, White-Tailed Deer and Elk)
DOSAGE AND ADMINISTRATION Of Xylazine
1. Dosage: Intravenously-0.5 ml/100 lbs body weight (0.5 mg/lb)
Intramuscularly-1.0 ml/100 lbs body weight (1.0 mg/lb)
Following injection of Xylazine, the animal should be allowed to rest quietly until the full effect has been reached.
These dosages produce sedation which is usually maintained for 1 to 2 hours, and analgesia which lasts for 15 to 30 minutes.
2. Preanesthetic to Local Anesthesia: Xylazine at the recommended dosages can be used in conjunction with local anesthetics, such as procaine or lidocaine.
3. Preanesthetic to General Anesthesia: Xylazine injection at the recommended dosage rates produces an additive effect to central nervous system depressants such as pentobarbital sodium, thiopental sodium and thiamyl sodium. Therefore, the dosage of such compounds should be reduced and administered to the desired effect. In general, only 1/3 to 1/2 of the calculated dosage of the barbiturates will be needed to produce a surgical plane of anesthesia. Post-anesthetic or emergence excitement has not been observed in animals preanesthetized with Xylazine.
Xylazine has been used successfully as a preanesthetic agent for pentobarbital sodium, thiopental sodium, thiamylal sodium, nitrous oxide, ether, halothane, glyceryl guaiacolate and methoxyflurane anesthesia.
Administer intramuscularly, either by hand syringe or syringe dart, in the heavy muscles of the croup or shoulder.
Fallow Deer (Dama dama)-2.0 to 4.0 mL/100 lbs body weight (2.0 to 4.0 mg/lb).
Mule Deer (Odocoileus hemionus)-1.0 to 2.0 mL/100 lbs body weight (1.0 to 2.0 mg/lb).
Sika Deer (Cervus nippon)-1.0 to 2.0 mL/100 lbs body weight (1.0 to 2.0 mg/lb).
White-Tailed Deer (Odocoileus virginianus)-1.0 to 2.0 mL/100 lbs body weight (1.0 to 2.0 mg/lb).
Elk (Cervus canadensis)-0.25 to 0.5 mL/100 lbs body weight (0.25 to 0.5 mg/lb).
Following injection of Xylazine, the animal should be allowed to rest quietly until the full effect has been reached. These dosages produce sedation which is usually maintained for 1 to 2 hours and analgesia which lasts for 15 to 30 minutes.
XYLAZINE INJECTION SIDE EFFECTS
Xylazine in horses and Cervidae, used at recommended dosage levels may occasionally cause slight muscle tremors, bradycardia with partial A-V heart block and a reduced respiratory rate. Movement in response to sharp auditory stimuli may be observed.
In horses, sweating, rarely profuse, has been reported following administration. In Cervidae, salivation, various vocalizations (bellowing, bleating, groaning, grunting, snoring) on expiration, audible grinding of molar teeth, protruding tongue and elevated temperatures have also been noted in some cases.
Xylazine Injection Precautions
Careful consideration should be given before administering to horses and Cervidae with significantly depressed respiration, severe pathologic heart disease, advanced liver or kidney disease, severe endotoxic or traumatic shock and stress conditions such as extreme heat, cold, high altitude or fatigue.
Do not use Xylazine in conjunction with tranquilizers.
Analgesic effect is variable, and depth should be carefully assayed prior to surgical/clinical procedures. Variability of analgesia occurs most frequently at the distal extremities of horses and Cervidae. In spite of sedation, the practitioner and handlers should proceed with caution since defense reactions may not be diminished.
Since an additive effect results from the use of Xylazine and the barbiturate compounds, it should be used with caution with these central nervous system depressants. Products known to produce respiratory depression or apnea, such as thiamylal sodium, should be given at a reduced dosage and, when injected intravenously, should be administered slowly. When intravenous administration of Xylazine is desired, avoid perivascular injection in order to achieve the desired effect. Studies have shown negligible evidence of tissue irritation, however, following perivascular injection of xylazine.
Intracarotid Arterial Injection Should Be Avoided. As with many compounds, including tranquilizers, immediate violent seizures followed by collapse may result from inadvertent administration into the carotid artery. Although the reaction with Xylazine is usually transient and recovery may be rapid and complete, special care should be taken to assure that the needle is in the jugular vein rather than the carotid artery.
Bradycardia and arrhythmia in the form of incomplete atrioventricular block have been reported following xylazine administration. Although clinically the importance of this effect is questioned, a standard dose of atropine given prior to or following xylazine will greatly decrease the incidence.
Sedation for transport is most successful if actual transportation is begun after the full effect of the drug has been reached and the animal’s stability is maintained while standing. In addition, it should be noted that animals under the influence of xylazine can be aroused by noise or other stimuli and this may increase the risk of injury.
As in all ruminants, it is preferable to administer Xylazine to fasted Cervidae as a safeguard against aspiration of food material into the lungs and/or bloat during deep sedation.
Care should be taken to administer Xylazine in the heavy muscles of the croup or shoulder. Injections given subcutaneously, intraperitoneally or into fat deposits will give unpredictable results.
Intra-arterial injection should be avoided, as with many compounds, including tranquilizers, immediate violent seizures followed by collapse may result from inadvertent administration into an artery.
The animal should not be disturbed during induction or until the full effect of the drug has been reached which is usually 10 to 15 minutes following injection.
The usual time to initial effect of the drug is 2 to 5 minutes. The administrator of the drug should be fully cognizant of this interval prior to administration of drug to free-ranging deer or elk, especially at night or in heavily wooded areas.
If the animal has been underdosed (faulty injection or miscalculation on weight) it is advisable to wait one hour before administering a second dose.
Adequate ventilation- especially in cages or crates- is mandatory; keep head and neck in position to insure patient air passage and to prevent aspiration of stomach contents.
During sedation, animals should be prevented from assuming lateral recumbency. A sternal recumbent position is desirable.
While under the effects of Xylazine, the animal should be protected from extreme hot or cold environments.
Efforts should be made to prevent patient from rising until almost complete recovery is attained.
The transportation of Cervidae given Xylazine should be carefully monitored to prevent excessive struggling, injury or death.
Hyperthermic reactions may occur, especially if the subject is in a highly excited state when the drug is administered. Hosing the head and entire body with cold water has usually proven to be an effective deterrent.
The safety of Xylazine has not been demonstrated in pregnant Cervidae. Avoid use during the breeding season.
Cervidae should be observed closely until all of the sedative effects of Xylazine are gone.
Care should be taken at all times when administering Xylazine to Cervidae. This is due to the method of administration (usually darting), the difficulty in estimating body weights and the accepted theory that wild animals are more unpredictable in their response to sedatives and analgesics than the domesticated species.