Anesthesia of Nondomestic Horses With Carfentanil and Antagonism With Naltrexone
Department of Veterinary Services, San Diego Wild Animal Park, Escondido, CA, USA
Abstract
Safe and effective anesthesia of nondomestic horses is challenging. Narcotic agents (carfentanil or etorphine) alone or in combination with other drugs (e.g., xylazine, acepromazine, detomidine) have been used to anesthetize nondomestic horses.
The purpose of this report is to:
1. Summarize published carfentanil dosages for anesthesia of the Mongolian wild horse (Equus przewalskii przewalskii) and the Hartmann’s mountain zebra (Equus zebra hartmannae)
2. Summarize unpublished preliminary carfentanil dosages for anesthesia of the Persian onager (Equus hemionus onager), eastern kiang (Equus kiang holdereri), and Somali wild ass (Equus africanus somalicus)
Planning for safe and effective anesthesia includes, but is not limited to, the following:
1. Accurate bodyweight
2. Experienced support staff
3. Precise dart placement
4. Advantages/disadvantages of premedications
5. Advantages/disadvantages of supplemental drugs used to prolong anesthesia
6. Prevalence of renarcotization
|
Species
|
Carfentanil
(mg/kg)
|
Carfentanil
(mg/100 lbs)
|
|
Mongolian wild horse
|
0.020
|
1.0
|
|
Hartmann’s mountain
|
0.011
|
0.5
|
|
Persian onager
|
0.055
|
2.5
|
|
Eastern kiang
|
0.044
|
2.0
|
|
Somali wild ass
|
0.046
|
2.1
|
Naltrexone: In each case, give naltrexone all IV at a 50:1 ratio (mg naltrexone to mg carfentanil). Of the species listed above, the Somali wild ass is the most likely one to renarcotize.
Pharmaceuticals
1. Wildnil (carfentanil), Wildlife Pharmaceuticals, Fort Collins, CO, USA
2. Naltrexone, Wildlife Pharmaceuticals, Fort Collins, CO, USA
3. Ketaset (ketamine), Aveco Co., Fort Dodge, IA, USA
4. Glyceryl Guaiacolate Powder, Western Medical Supply, Arcadia, CA, USA
5. Diprivan (propofol), Stuart Pharmaceuticals, Wilmington, DE, USA
6. Dormosedan (detomidine), Pfizer Inc., West Chester, PA, USA