Evaluation of gastrointestinal activity in healthy rabbits by means of duplex Doppler ultrasonography

Point of Care Ultrasound in Exotic Animal Emergency and Critical Care

Exotic pets are presented to veterinary clinics with increasing frequency for routine, urgent, and emergency needs. With these increased visits, owners' expectations for high-quality veterinary care are also increasing. Many presenting complaints of reptiles, birds, and small mammals can benefit from the use of point of care ultrasound (POCUS) to establish a minimum database, aid in triage, and help guide further diagnostics, treatment, and prognostic discussions with the owner. Hospitalized exotic patients can also have their progress tracked and better assessed with the aid of POCUS.

Intramuscular Alfaxalone-Butorphanol-Midazolam Compared with Ketamine-Butorphanol- Midazolam in New Zealand White Rabbits

Rabbits are a common companion animal and research subject and frequently require sedation to facilitate procedures. The objective of this study was to compare the effects of intramuscular butorphanol and midazolam combined with either alfaxalone or ketamine in rabbits. In a complete crossover study, healthy New Zealand white rabbits (n = 9; age, 6 mo) randomly received midazolam (1 mg/kg IM) and butorphanol (1 mg/kg IM) combined with either alfaxalone (2 mg/kg IM; ABM) or ketamine (5 mg/kg IM; KBM). Time to first effects, recumbency, and standing (recovery) were recorded. Every 5 min during recumbency, an investigator who was blind to treatment group collected serial physiologic parameters and sedation scores. At 5 min after rabbits became recumbent, manipulations were performed to mimic 2-view radiography and a cephalic intravenous catheter was placed. At 30 min after drug injection, flumazenil (0.05 mg/kg IM) was administered for reversal. Food consumption and fecal output were measured for 3 d after each study day. Time to standing and duration of recumbency differed significantly between groups. The median (range) of the total sedation score for ABM was 10 (8 to 10) and for KBM was 10 (6 to 10). Sham radiographs were successful in all rabbits in both groups. Physiologic parameters were not significantly different between groups over time. At 24 h after drug treatment, KBM-treated rabbits showed reduced food intake and both groups showed reduced fecal output. Total sedation scores decreased significantly over time in KBM rabbits ( P < 0.001) but not in ABM rabbits (P = 1). The duration of recumbency was significantly longer in ABM rabbits than in KBM rabbits. Both protocols produced sufficient sedation for radiograph acquisition without clinically significant adverse effects.

Effects of a Single Opioid Dose on Gastrointestinal Motility in Rabbits (Oryctolagus cuniculus): Comparisons among Morphine, Butorphanol, and Tramadol

The aim of this study was to evaluate and compare the effects of single doses of butorphanol, morphine, and tramadol on gastrointestinal motility in rabbits (Oryctolagus cuniculus) using non-invasive imaging methods, such as radiographic barium follow through and ultrasonographic contraction counts. Time-lapse radiographic and ultrasound examinations were performed before and after a single intramuscular dose of 5 mg kg⁻¹ butorphanol, 10 mg kg⁻¹ morphine, or 10 mg kg⁻¹ tramadol. Pyloric and duodenal contraction counts by ultrasonography and radiographic repletion scores for the stomach and caecum were analysed using a mixed linear model. No significant effect was noted on ultrasound examinations of pyloric and duodenal contractions after administration of an opioid treatment. Morphine had a significant effect on the stomach and the caecum repletion scores, whereas butorphanol had a significant effect only on the caecum repletion score. Tramadol had no significant effect on the stomach or caecum repletion scores. The present findings suggest that a single dose of 5 mg kg⁻¹ butorphanol or 10 mg kg⁻¹ morphine temporarily slows gastrointestinal transit in healthy rabbits, preventing physiological progression of the alimentary bolus without the induction of ileus. In contrast, a single dose of 10 mg kg⁻¹ tramadol has no such effects.