The most frequently used mixture for wildlife immobilization is ketamine/xylazine (also known as ketamine/rompun). See dose below. Ketamine causes severe muscle stiffness which will lessen the animal's ventilation. Ketamine will also cause seizures in some animals. Xylazine is a potent cardiac depressant. This cardiac depression is more serious in aggitated or excited animals becasue of the presence of epinephrine (adrenaline) in their blood. Since most of the wildlife being immobilized it aggitated or excited, this drug will cause serious problems. I do not suggest the use of ketamine/xylazine. I much prefer ketamine/midazolam or telazol over any cocktail with xylazine.
Most frequently used drugs
Atropine is used at a dose of 0.02 mg/kg if mixed with an immobilizing agent or given later intramuscularly, and 0.01mg/kg if given intravenously. It will speed up the heart in a xylazine-immobilized animal that you don't want to get light by reversing the xylazine. It will decrease the secretions of the oral cavity and respiratory system. Use it if you get a lot of salivation or if you hear fluid in the airway. It is very safe at these doses so if you are in question, give it.
Atropine comes in two strengths. Small animal, often has an SA after it on the label and Large animal with LA. They have to make it pretty easy for us vets. SA is 0.5 mg/cc and LA is 15 mg/cc. So to save on the math use these guidelines.
|Small Animal||Large Animal|
|IV DOSE||1 mL/100 lbs.||0.1mL/300 lbs.|
|IM DOSE||1mL/50 lbs.||0.1mL/150 lbs.|
Acetylpromazine "Acepromazine", "Ace", is a tranquilizer frequently mixed with ketamine. It will be of little use alone. I usually mix 0.5mL into a bottle of ketamine.
Carfentanil is one of the powerful narcotics used in hoofed animals like moose, elk, deer, bison. It is not recommended for use in canine or feline species. Narcotics, like this and etorphine (M-99) will depress the animal's ventilation. Be aware of this and monitor the color of the gums and use that as a measure of how well the animal is oxygenating its blood. Carfentanil can be reversed with Naltrexone.
Midazolam "Versed" is a very good tranquilizer to mix with ketamine. It eliminates the seizures seen in other ketamine cocktails and is very sparing on the cardiovascular system. It is mixed in equal parts with ketamine. Use 1 mL of this mixture for each 5 - 10 lbs body weight. Telazol is a mixture of two drugs that are very similar to ketamine and midazolam. Midazolam alone will be of little use in immobilization.
Ketamine is the most commonly used drug in wildlife immobilization. Like any drug it
has some drawback but it can and has been used safely in a very wide variety of species.
It should always be mixed with a tranqulizer, acepromazine, midazolam, medetomidine, or xylazine. Calculate the dose based on the amount of ketamine you want to give. Ketamine
is usually dosed at 5 - 10 mg per pound.
The most common cocktails are:
Ketamine/Xylazine: Mix 2 mL of Xylazine (100mg/mL) with 10 ml of ketamine. I would strongly suggest adding atropine (0.25 mL of Large Animal Atropine) to this cocktail to lessen the cardiac depressing effects of the xylazine. You then give this mixture at a dose of 1 mL per 8 - 16 lbs. This will give a dose of ketamine that is 5 - 10 mg/lb as mentioned above. In larger species, you will use the 1 mL/16 lbs and in smaller species or highly aggiated animals you will use the 1 mL/8lbs.
The xylazine portion of the cocktail can be reversed with yohimbine(0.15 mg/kg IV), or tolazoline
(3 mg/kg IV.) It is important to remember that when you reverse the xylazine portion of a
ketamine/xylazine cocktail the animal will be under the full influence of the ketamine. If
you are within the first 45 minutes of the immobilization, you may well see the severe
muscle stiffness and seizures due to the ketamine.
Ketamine/Acepromazine: Mix 0.5 mL Acepromazine with 10 mL of ketamine.
Ketamine/Midazolam: Mix equal parts of ketamine and midazolam.
Ketamine causes severe muscle stiffness and will precipitate seizures in many species. Acepromazine may even increase the likelihood of seizures in canine species. Xylazine will help lessen the frequency and severity of seizures. Midazolam will greatly decrease the likelihood of seizures.
Xylazine although frequently used, has some serious drawbacks. It is VERY depressing to the heart. If the animal is excited, and so many are, the deprssing effects are even greater. These effects can range from slowing of the heart, to skipping beats, to stopping the heart entirely. NEVER use xylazine alone to immobilize an animal. ALWAYS use atropine if you are using xylazine. Xylazine can be reversed with yohimbine(0.15 mg/kg IV), or telazoline (3 mg/kg IV.) It is important to remember that when you reverse the xylazine portion of a ketamine/xylazine cocktail the animal will be under the full influence of the ketamine. If you are within the first 45 minutes of the immobilization, you may well see the severe muscle stiffness and seizures due to the ketamine.
Here is an ECG from an animal immobilized with Ketamine/xylazine. Note the cardiac depression resulting in missed beats shown by the red arrows.
Medetomidine "Dormitor" Is a new sedative that is very similar in its actions to xylazine. It has many of the same cardiac depressing effects. It is safer to use on highly aggitated or excited animals because it is affected less by the presence of epinephrine. Use atropine here as you would with xylazine. This drug constricts the peripheral blood vessels, so it will make it much more difficult to find a vein for drawing blood or injecting a reversing agent. Medetomidine can be reversed with atipamazole (follow label dosages), or yohimbine (0.20mg/kg IV>.
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