Elephant Formulary

© 2003-17 Susan K. Mikota DVM and Donald C. Plumb, Pharm.D. Published by
Elephant Care International

Disclaimer: the information on this page is used entirely at the reader's discretion, and is made available on the express condition that no liability, expressed or implied, is accepted by the authors or publisher for the accuracy, content, or use thereof.



Elephant specific information, if available, is in blue.

Hyaluronidase is an enzyme that facilitates drug absorption.



a) 3000-7500IU/dart (Raath, 1999).


b) Thirty-seven wild African elephants were immobilized as follows:  Calves (4-6 years; n=4) were immobilized with 1 mg carfentanil and adults with 3 mg carfentanil mixed with 1500 IU of hyaluronidase.  All animals were reversed with naltrexone at a rate of 100 mg for every mg of carfentanil used.  For 15 elephants, mean minutes elapsed for initial effect of standing still, recumbency, and recovery following reversal were 5.0 ± 1.6, 10.7 ± 3.9, and 5.9 ± 3.9 respectively (Karesh et.al. 1997).


c,e) Twenty free-ranging adult wild African elephants in northern Botswana were immobilized with a mean (±SD) of 9.5 ± 0.5 mg etorphine hydrochloride and 2000 IU hyaluronidase by i.m. dart (Osofsky, 1997).


d) Azaperone (60-100 mg) was combined with etorphine (7-15 mg) and hyaluronidase 1500-3000 IU) in a translocation operation of 26 elephants in central Kenya.  Induction time was 7-15 minutes.  Five elephants died from metabolic changes unrelated to drugs administered.  (Njumbi et.al. 1996).  (Author’s (Mikota) note: hyaluronidase (hyalase) is incorrectly described as a tranquilizer in this article).


f,g) 4500 IU (Kock et.al. 1993).


Elephant References:

a) Raath,J.P., 1999. Relocation of African elephants. In: Fowler,M.E. and Miller,R.E. (Editors), Zoo and Wild Animal Medicine: Current Therapy 4. W.B. Saunders, Philadelphia, PA, USA pp. 525-533

b) Karesh,W.B., Smith,K.H., Smith,F., Atalia,M., Morkel,P., Torres,A., House,C., Braselton,W.E., and Dierenfeld,E.S.  1997. Elephants, buffalo, kob, and rhinoceros:  immobilization, telemetry, and health evaluations.  Proceedings American Association of Zoo Veterinarians. Pages: 296-230

c) Osofsky,S.A. 1997. A practical anesthesia monitoring protocol for free-ranging adult African elephants (Loxodonta africana). Journal of Wildlife Diseases 33:(1):72-77  
Abstract: Twenty free-ranging adult African elephants in northern Botswana were immobilized with a mean (± SD) of 9.5 ± 0.5 mg etorphine hydrochloride and 2000 IU hyaluronidase by i.m. dart. The mean time to recumbency was 8.7 ± 2.4 min. All animals were maintained in lateral recumbency. The anaesthesia monitoring protocol included cardiothoracic auscultation; palpation of auricular pulse for quality and regularity; checking of rectal temperature, and monitoring of respiratory and heart rates. Results of basic physiological measurements were similar to those of previous field studies of African elephants immobilized with etorphine or etorphine-hyaluronidase. In addition, continuous real-time pulse rate and percent oxygen saturation of haemoglobin (SpO2) readings were obtained on 16 elephants with a portable pulse oxygen meter. Duration of pulse oximetry monitoring ranged from 3 to 24 min (mean ±SD = 8.2 ± 4.8 min). Differences between minimum and maximum SpO2 values for any given elephant ranged from 1 to 6 percentage points, evidence for relatively stable trends. The SpO2 readings ranged from 70% to 96% among the 16 elephants, with a mean of 87.3 ± 2.8%. 15 of 16 elephants monitored with a pulse oximeter had mean SpO2 values 
≥ 81 ± 2.4%, with 11 having mean SpO2 values ≥ 85 ± 1.5%. All 20 animals recovered uneventfully following reversal: diprenorphine at 23.3 ± 1.5 mg (IV) with 11.7 ± 0.5 mg IM, or 24 mg diprenorphine given all IV.

d) Njumbi,S.T., Waithaka,J., Gachago,S., Sakwa,J., Mwathe,K., Mungai,P., Mulama,M., Mutinda,H., Omondi,P., and Litoroh,M. 1996. Translocation of elephants: the Kenyan experience. Pachyderm 22:61-65

e) Osofsky,S.A.  1995. Pulse oximetry monitoring of free-ranging African elephants (Loxodonta africana) immobilized with an etorphine/hyaluronidase combination antagonized with diprenorphine. Joint Conference AAZV/WDA/AAWV. Pages: 237-277

f) Kock,M.D., Martin,R.B., and Kock,N. 1993. Chemical immobilization of free-ranging African elephants (Loxodonta africana) in Zimbabwe, using etorphine (M99) mixed with hyaluronidase, and evaluation of biological data collected soon after immobilization. Journal of Zoo and Wildlife Medicine 24:(1):1-10  Abstract:Sixteen adult female free-ranging elephants were immobilized in July 1990, using a mean (±SE) dose per animal of 11.6 ± 0.3 mg of etorphine (M99) mixed with a standard dose of hyaluronidase (4500 IU), at the Sengwa Wildlife Research Area, Zimbabwe, to attach telemetry and infrasound detection collars. The 16 elephants were reimmobilized in December 1990, using higher doses of etorphine (standardized at 15 mg total dose) with hyaluronidase (4500 IU), to remove the collars. The higher doses of etorphine produced more rapid inductions. Biological data were collected on both occasions. Significant differences in selected measures indicative of stress, including lactic dehydrogenase and aspartate transaminase, were seen between immobilizations. Comparisons were made of selected health measures between samples collected in the early winter and late winter/early spring season. Significant differences were seen with total protein, albumin, urea nitrogen, creatinine, calcium, magnesium, inorganic phosphorus, chloride, and alanine transaminase. 

g) Kock,R.A., Morkel,P., and Kock,M.D., 1993. Current immobilization procedures used in elephants. In: Fowler,M.E. (Editor), Zoo and Wild Animal Medicine Current Therapy 3. W.B. Saunders Company, Philadelphia, PA, USA pp. 436-441

See also:


Hoare,R. 1999. Reducing drug immobilization time in the field immobilization of elephants. Pachyderm 27:(Jan-Dec):49-54   Note: doses not specified.

Morton,D.J. and Kock,M.D. 1991. Stability of hyaluronidase in solution with etorphine and xylazine. J.Zoo and Wildlife Medicine 22:(3):345-347  Abstract: During capture of free-living wildlife, stress is potentially the greatest problem encountered. For this reason, reduction in induction time during immobilization is of paramount importance. Hyaluronidase reduces induction times, although no reports have assessed stability of the enzyme in drug mixtures used for chemical capture. This report presents information on the stability of hyaluronidase in combination with etorphine and xylazine, one of the most common drug mixtures used in chemical immobilization of wildlife. Hyaluronidase activity remains high for at least 48 hr, provided storage temperatures can be maintained at less than or equal to 30º C. Storage at greater than or equal to 40ºC is associated with rapid loss of enzyme activity in the mixture.

Dosage Forms/Preparations

Hyalase, CP Pharmaceuticals

Hyalase, 1500 IU/ampule, Fisons Pharmaceuticals, 1624 Chloorkop, South Africa

Hyalase, Zimethicals, Harara, Zimbabwe

Hyaluronidase, Sigma, St.Louis, Missouri, 61378, USA

Hyaluronidase, 5000 IU/vial, Kyron Labs, South Africa