title: Romifidine and low doses of tiletamine-zolazepam in dogs.
abstract: OBJECTIVE
  To evaluate clinical effects of romifidine and low doses of tiletamine-zolazepam (TZ) in dogs.
  
  
  METHODS
  Randomized "blinded" cross-over study.
  
  
  METHODS
  Six healthy beagle dogs (two males, four females).
  
  
  METHODS
  In separate preliminary experiments dogs received intravenous (IV) tiletamine-zolazepam (TZ) at 1 and 2 mg kg(-1). For the main trial, dogs received romifidine (R) followed 5 minutes later by IV at six dose regimens: R40TZ1, R60TZ1, R80TZ1 (Romifidine at 40, 60, 80 μg kg(-1) and TZ at 1 mg kg(-1)), R40TZ2, R60TZ2 and R80TZ2 (Romifidine at 40, 60, 80 μg kg(-1) and TZ at 2 mg kg(-1)). Dogs underwent endotracheal intubation, but breathed room air. Cardiorespiratory variables were measured and arterial blood analyzed. Quality of sedation, duration of anaesthesia and time to recovery (TR) were recorded. Data were analysed by anova or Friedman test as relevant.
  
  
  RESULTS
  Endotracheal intubation was possible with all romifidine/TZ combinations but not with TZ alone. Mean times (minutes) from TZ injection to return of pedal reflex were 1-3 minutes for TZ alone, and 9-17 minutes for romifidine combinations. In the main trial (romifidine combinations) mean time (minutes) to standing increased with increasing dosage (R40TZ1 13; R80TZ2 32). Five minutes after TZ administration, when compared with baseline arterial blood pressures and arterial carbon dioxide had increased, and respiratory rate, pH and arterial oxygen tensions decreased, these changes becoming statistically significant with the higher dose rates. One dog in R60TZ2 and three dogs in R80TZ2 became hypoxaemic.
  
  
  CONCLUSIONS
  Romifidine improves the quality and lengthens the duration of anaesthesia induced by TZ. The combination provides a suitable protocol for induction of or short-term anaesthesia in healthy dogs. However, the higher doses cause cardiovascular stimulation and respiratory depression, and precautions should be taken accordingly.
authors.affiliation: Department of Animal Medicine and Surgery, University of Córdoba, Córdoba, Spain.
authors.forename: Rafael J
authors.initials: RJ
authors.lastname: Gómez-Villamandos
authors.forename: Carmen
authors.initials: C
authors.lastname: Martínez
authors.forename: Rocío
authors.initials: R
authors.lastname: Navarrete
authors.forename: Juan
authors.initials: J
authors.lastname: Morgaz
authors.forename: Juan M
authors.initials: JM
authors.lastname: Domínguez
authors.forename: Ignacio
authors.initials: I
authors.lastname: López
authors.forename: Pilar
authors.initials: P
authors.lastname: Muñoz
authors.forename: Andrés
authors.initials: A
authors.lastname: Fernández
authors.forename: María M
authors.initials: MM
authors.lastname: Granados
mesh_terms: D000771:Anesthesia, Intravenous / Q000379:methods / Q000662:veterinary*; D000777:Anesthetics; D019162:Anesthetics, Combined; D000778:Anesthetics, Dissociative; D000818:Animals; D014151:Anti-Anxiety Agents; D001794:Blood Pressure / Q000187:drug effects; D016292:Procedural Sedation / Q000379:methods / Q000662:veterinary; D004285:Dogs; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D007093:Imidazoles; D008297:Male; D056152:Respiratory Rate / Q000187:drug effects; D013992:Tiletamine; D015041:Zolazepam
chemical_list: D000777:Anesthetics; D019162:Anesthetics, Combined; D000778:Anesthetics, Dissociative; D014151:Anti-Anxiety Agents; D007093:Imidazoles; D013992:Tiletamine; C076257:romifidine; D015041:Zolazepam
keywords: anaesthesia; dogs; romifidine; tiletamine; zolazepam