Sedative and cardiorespiratory effects of medetomidine, medetomidine-butorphanol, and medetomidine-ketamine in dogs.
OBJECTIVE
To determine sedative and cardiorespiratory effects of i.m. administration of medetomidine alone and in combination with butorphanol or ketamine in dogs.


METHODS
Randomized, crossover study.


METHODS
6 healthy adult dogs.


METHODS
Dogs were given medetomidine alone (30 micrograms/kg [13.6 micrograms/lb] of body weight, i.m.), a combination of medetomidine (30 micrograms/kg, i.m.) and butorphanol (0.2 mg/kg [0.09 mg/lb], i.m.), or a combination of medetomidine (30 micrograms/kg, i.m.) and ketamine (3 mg/kg [1.36 mg/lb], i.m.). Treatments were administered in random order with a minimum of 1 week between treatments. Glycopyrrolate was given at the same time. Atipamezole (150 micrograms/kg [68 micrograms/lb], i.m.) was given 40 minutes after administration of medetomidine.


RESULTS
All but 1 dog (given medetomidine alone) assumed lateral recumbency within 6 minutes after drug administration. Endotracheal intubation was significantly more difficult when dogs were given medetomidine alone than when given medetomidine and butorphanol. At all evaluation times, percentages of dogs with positive responses to tail clamping or to needle pricks in the cervical region, shoulder region, abdominal region, or hindquarters were not significantly different among drug treatments. The Paco2 was significantly higher and the arterial pH and Pao2 were significantly lower when dogs were given medetomidine and butorphanol or medetomidine and ketamine than when they were given medetomidine alone. Recovery quality following atipamezole administration was unsatisfactory in 1 dog when given medetomidine and ketamine.


CONCLUSIONS
Results suggested that a combination of medetomidine with butorphanol or ketamine resulted in more reliable and uniform sedation in dogs than did medetomidine alone.
Ko
J C
JC
Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville 32608, USA.
Fox
S M
SM
Mandsager
R E
RE
D000759:Adjuvants, Anesthesia / Q000627:therapeutic use; D000316:Adrenergic alpha-Agonists / Q000627:therapeutic use; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000494:pharmacology*; D000778:Anesthetics, Dissociative / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002077:Butorphanol / Q000008:administration & dosage / Q000494:pharmacology*; D018592:Cross-Over Studies; D004285:Dogs / Q000502:physiology*; D004338:Drug Combinations; D006024:Glycopyrrolate / Q000627:therapeutic use; D006339:Heart Rate / Q000187:drug effects; D006993:Hypnotics and Sedatives / Q000008:administration & dosage / Q000494:pharmacology*; D007093:Imidazoles / Q000627:therapeutic use; D007273:Injections, Intramuscular / Q000662:veterinary; D007442:Intubation, Intratracheal / Q000662:veterinary; D007649:Ketamine / Q000008:administration & dosage / Q000494:pharmacology*; D020926:Medetomidine / Q000008:administration & dosage / Q000494:pharmacology*; D010147:Pain Measurement / Q000662:veterinary; D011897:Random Allocation; D012119:Respiration / Q000187:drug effects
D000759:Adjuvants, Anesthesia; D000316:Adrenergic alpha-Agonists; D000701:Analgesics, Opioid; D000778:Anesthetics, Dissociative; D004338:Drug Combinations; D006993:Hypnotics and Sedatives; D007093:Imidazoles; C050701:atipamezole; D007649:Ketamine; D020926:Medetomidine; D002077:Butorphanol; D006024:Glycopyrrolate