Lactated Ringer’s solution (10 mL/kg IV bolus over 10 minutes) was administered, after which Victor’s systolic blood pressure measured 100 mm Hg via Doppler. IV fluid therapy was continued at 18 mL/hour (10.5 mL/hour to correct 7% dehydration over 12 hours + 4.5 mL/kg/hour for maintenance). Analgesia was provided with lidocaine (loading dose, 2 mg/kg IV, followed by 100 µg/kg/minute CRI) and buprenorphine (0.04 mg/kg IV every 8 hours). After hydration was restored (≈12 hours after admission), assisted feedings with a liquid recovery diet appropriate for rabbits were given every 6 hours. Thermal support was provided with a heated incubator.
Victor’s anorexia, lack of defecation, and lethargy were caused by inadequate postoperative pain management. The currently accepted dosage of meloxicam in rabbits is 1 mg/kg PO every 24 hours; however, this is based on pharmacokinetic studies of therapeutic plasma drug concentrations in dogs and cats.2,3 This dosage has been shown to be safe in healthy rabbits.2,3
Lidocaine CRIs are a common analgesic modality in rabbit medicine. Studies have shown that rabbits receiving lidocaine CRIs have reduced isoflurane mean alveolar concentration and superior recovery time from elective ovariohysterectomy compared with rabbits receiving buprenorphine.4,5
Treatment of RGIS depends on the patient’s overall condition (see Treatment at a Glance). Victor’s case illustrates the importance of acquiring vital signs (including blood pressure) as part of the initial assessment, as findings in this patient supported compensatory shock and guided appropriate treatment. Noninvasive blood pressure measurement in rabbits may under- or overestimate arterial blood pressure.6 Doppler systolic blood pressure <80 mm Hg taken from the dorsal carpal branch of the radial artery is a reliable indicator of arterial hypotension in young, healthy pet rabbits.7 Other studies state that hypotension is present when systolic blood pressure is <90 mm Hg.8