Measuring the Effects of Detomidine and Medetomidine Alone and in Combination with Ketamine on Tear Production and Intraocular Pressure in Common Buzzards (Buteo buteo).

The purpose of this study was to measure the effects of detomidine and medetomidine alone or in combination with ketamine on Schirmer tear test I (STT I) results and intraocular pressures (IOPs) in the common buzzard (Buteo buteo). Fourteen ophthalmologically healthy common buzzards were randomly assigned to 1 of 2 α-2 adrenoreceptor agonist groups: a detomidine group (group 1) and a medetomidine group (group 2). The detomidine group had 2 subgroups, detomidine alone or in combination with ketamine. Similarly, the medetomidine group had 2 subgroups, medetomidine alone or in combination with ketamine. Five minutes after α-2 adrenoreceptor agonist administration, the first measurements of STT I and IOP were collected. Ketamine was injected intramuscularly immediately after the first measurements were recorded. Schirmer tear test I and IOP measurements were repeated 5 minutes after ketamine administration. Measurements were obtained for 3 subgroups per agonist grouping: baseline 1, detomidine alone and detomidine with ketamine for group 1, and baseline 2, medetomidine alone and medetomidine with ketamine for group 2. Both IOP and STT I decreased significantly after sedation, anesthesia, or both. Intraocular pressure was significantly lower in the detomidine-ketamine group compared with the detomidine alone group. The IOP and STT I significantly decreased in both the medetomidine alone and medetomidine-ketamine groups when compared with those for all 14 unanesthetized animals before administering the α-2 adrenoreceptor agonist and ketamine. When α-2 adrenoreceptor agonists were considered as a single group (groups 1 and 2 combined), IOP also showed a significant decrease in the α-2 adrenoreceptor agonist-ketamine groups compared with the α-2 adrenoreceptor agonists alone, but STT I did not. According to the results obtained from these common buzzards, no statistical differences were found between the detomidine and medetomidine (alone) groups or detomidine-ketamine and medetomidine-ketamine groups in terms of STT I and IOP.

Influence of Anesthesia on Grading of Canine Hip Dysplasia.

This study aimed to evaluate the effect of anesthesia on grading of canine hip dysplasia. For this purpose, 20 middle-sized healthy dogs from different breeds were used. Radiographs were taken using 4 different imaging methods, including the hip-extended, subluxation, distraction, and compression. This procedure was repeated 4 times for each dog, while the dogs were unanesthetized and anesthetized with 3 different anesthetic protocols at 15-day intervals (propofol [5 mg/kg, IV]; diazepam [0.5 mg/kg, IV] / ketamine [20 mg/kg, IV]; medetomidine [0.05 µg/kg, IM] / ketamine [20 mg/kg, IM]). The radiographs were taken and evaluated by the same investigator to prevent interobserver variation. Because of the radiographic positioning difficulty, unanesthetized radiographic imaging revealed higher repetition number than the anesthetized; therefore, radiation safety decreased. The administration of diazepam/ketamine and medetomidine/ketamine was sufficient in terms of both muscle relaxation and duration of the anesthesia; however, some dogs under propofol anesthesia were required maintenance doses to complete radiographic imaging procedure. Unanesthetized radiographic images of the dogs had significantly lower (P < .001) hip score, distraction index (DI), subluxation index (SI), and higher compression index (CI) (P< .001), when compared with anesthetized radiographic images. When compared the anesthetic protocols, propofol revealed lower (P< 0.001) hip score, DI, SI, and higher (P < .001) CI than medetomidine/ketamine. Medetomidine/ketamine is the most appropriate anesthetic protocol for detailed radiographic evaluation of CHD considering both muscle relaxation and duration of action.