Determination of a safe sedative combination of dexmedetomidine, ketamine and butorphanol for minor procedures in dogs by use of a stepwise optimization method.

BACKGROUND: In veterinary practice, most minor procedures such as radiographs, skin biopsies, and wound treatments require sedation. The combination of butorphanol, ketamine, and dexmedetomidine is commonly used, but the ideal dosages for this combination have not been defined. This randomized prospective clinical 3-phases trial initially tested eight clinically relevant combinations of intramuscular administration in 50 dogs (phase 1). The quality of each combination was rated using a purposefully developed negative score (NS; 0-21.5, the lower the NS the better the quality of sedation) to judge the quality of sedation, the occurrence of side effects, and the need for additional anaesthetics. Based on the results of the NS, the eight combinations were divided into "promising" and "unsatisfactory" subgroups. In phase 2, a new combination (N) was calculated and tested in six dogs replacing the worst of the eight initial combinations. This procedure was repeated until the NS could not be improved any further. In phase 3, the best combination was tested in 100 adult dogs undergoing diagnostic or therapeutic procedures. RESULTS: The optimal combination established was dexmedetomidine 0.005 mg/kg, ketamine 1 mg/kg, and butorphanol 0.3 mg/kg with a median NS of 1.5 (interquartile range 1.5-2.4). In all 112 dogs receiving this combination, the quality of sedation was satisfactory and no severe side effects were detected. CONCLUSIONS: The application of this optimization method allowed the calculation of an optimal drug combination to sedate cardiovascularly healthy dogs. After having being tested in 112 animals, this combination can consequently be considered safe. Therefore, this combination can now be used in daily clinical practice for cardiovascularly healthy adult dogs undergoing minor procedures.

Comparison of the biomechanical properties of a ventral cervical intervertebral anchored fusion device with locking plate fixation applied to cadaveric canine cervical spines.

OBJECTIVE: To evaluate fixation properties of a new intervertebral anchored fusion device and compare these with ventral locking plate fixation. STUDY DESIGN: In vitro biomechanical evaluation. ANIMALS: Cadaveric canine C4-C7 cervical spines (n = 9). METHODS: Cervical spines were nondestructively loaded with pure moments in a nonconstraining testing apparatus to induce flexion/extension while angular motion was measured. Range of motion (ROM) and neutral zone (NZ) were calculated for (1) intact specimens, (2) specimens after discectomy and fixation with a purpose-built intervertebral fusion cage with integrated ventral fixation, and (3) after removal of the device and fixation with a ventral locking plate. RESULTS: Both fixation techniques resulted in a decrease in ROM and NZ (P < .001) compared with the intact segments. There were no significant differences between the anchored spacer and locking plate fixation. CONCLUSION: An anchored spacer appears to provide similar biomechanical stability to that of locking plate fixation.