The effect of intramuscular dexmedetomidine-butorphanol combination on tear production in dogs.

This study assessed the effects of a combination of dexmedetomidine and butorphanol on the Schirmer tear test I (STT I) values in dogs. Ninety-eight dogs were sedated with an intramuscular injection of a combination of dexmedetomidine, 5 mg/kg body weight (BW), and butorphanol, 0.2 mg/kg BW. The effects of dexmedetomidine were reversed by administering atipamezole at the end of the procedure. The combination of dexmedetomidine and butorphanol significantly decreased tear production 15 minutes after sedation. The STT I values 15 minutes after reversal of dexmedetomidine with atipamezole were significantly higher than the STT I values 15 minutes after sedation but were significantly lower than the STT I values before sedation. Gender, weight, duration of sedation, right or left eye did not affect STT I values after sedation. It is recommended that dogs sedated with a combination of dexmedetomidine and butorphanol be treated with a tear substitute to combat decreased tear production