Doses - XYLAZINE HCL
Dogs: 
a) 1.1 mg/kg IV, 1.1 - 2.2 mg/kg IM or SQ (Package Insert; Rompun® - Miles) b) 0.6 mg/kg IV IM as a sedative (Morgan 1988)
c) To treat a hypoglycemic crises (with IV dextrose): 1.1 mg/kg IM (Schall 1985)
d) 0.5 - 1.0 mg/kg IV or 1 - 2 mg/kg IM (Davis 1985b)
e) 0.55 mg/kg IM (Mandsager 1988)
Cats: 
a) 1.1 mg/kg IV, 1.1 - 2.2 mg/kg IM or SQ (Package Insert; Rompun®¯Miles) b) As an emetic: 0.44 mg/kg IM (Morgan 1988), (Riviere 1985)
c) 0.5 - 1.0 mg/kg IV or 1 - 2 mg/kg IM (Davis 1985b)
d) 0.55 mg/kg IM (Mandsager 1988)
Rabbits/Rodents/Pocket Pets:
Rabbits: For minimally invasive procedures lasting less than 30-45 minutes: 5 mg/kg once
SubQ or IM in combination with ketamine (35 mg/kg)
Mice/Rats: General anesthesia 13 mg/kg once IP in combination with ketamine (87 mg/kg)
Hamsters/Guinea pigs: General anesthesia 8 - 10 mg/kg once IP in combination with ketamine (200 mg/kg for hamsters & 60 mg/kg for Guinea pigs) (Huerkamp 1995)
Cattle: 
Caution: Cattle are extremely sensitive to xylazine's effects; be certain of dose and dosageform. Pretreatment with atropine can decrease the bradycardia and hypersalivation seen. a) 0.05 - 0.15 mg/kg IV; 0.10 - 0.33 mg/kg IM. If administering IM use an 18 or 20gauge needle at least 1.5 inches long. Intravenous route may stress cardiovascularfunction. (Thurmon and Benson 1986)
b) 0.044 - 0.11 mg/kg IV; 0.22 mg/kg IM (Mandsager 1988)
Horses: 
a) 1.1 mg/kg IV; 2.2 mg/kg IM. Allow animal to rest quietly until full effect is reached.(Package Insert; Rompun® - Miles) b) Sedative/analgesic for colic: 0.3 - 0.5 mg/kg IV; repeat as necessary (Muir 1987)
c) Prior to guaifenesin/thiobarbiturate anesthesia: 0.55 mg/kg IV; Prior to ketamine induction: 1.1 mg/kg IV; In combination with opioid/tranquilizers (all IV doses):
Note: the manufacturers state that xylazine should not be used in conjunction with tranquilizers (Thurmon and Benson 1987)
Sheep & Goats: Note: Use xyalazine with extreme caution in these species.
a) 0.05 - 0.10 mg/kg IV; 0.10 - 0. 22 IM (Thurmon and Benson 1986)
b) 0.044 - 0.11 mg/kg IV; 0.22 mg/kg IM (Mandsager 1988)
Exotics:
a) An excellent list of suggested dosages can be found on page 359 of Veterinary
Pharmacology and Therapeutics, 6th Ed., Booth, NH & McDonald, LE, Eds.; 1988;
Iowa State University Press; Ames, Iowa
Monitoring Parameters - 1) Level of anesthesia/analgesia; 2) Respiratory function; cardiovascularstatus (rate, rhythm, BP if possible); 3) Hydration status if polyuria present
Client Information - Xylazine should only be used by individuals familiar with its use.
Dosage Forms/Preparations/FDA Approval Status/Withholding Times - Veterinary-Approved Products:
Rompun® (Bayer) Gemini® (Butler); AnaSed® (Lloyd);Sedazine® (Fort Dodge) (Rx)
Approved for use (depending on strength) in dogs, cats, horses, deer, and elk.
While xyalzine is not approved for use in cat le in the USA, at labeled doses in Canada it reportedly has been assigned withdrawal times of 3 days for meat and 48 hours for milk.
FARAD has reportedly suggested a withdrawal of 7 days for meat and 72 hours for milk forextra-label use in the USA.
Human-Approved Products: None