OBJECTIVE:To report clinical, surgical, and pathological findings in client-owned rabbits with histologically confirmed appendicitis.ANIMALS:19 rabbits.PROCEDURES:Medical records for client-owned rabbits that had a histologic diagnosis of appendicitis were reviewed.RESULTS:Median age of the rabbits at presentation was 24.0 months (range, 4 to 84 months). Seventeen cases occurred during the summer and fall seasons. Decreased appetite (17/19 rabbits), abnormal rectal temperature (hyperthermia, 9/16 rabbits; hypothermia, 4/16 rabbits), hypocalcemia (8/11 rabbits), and hypoglycemia (7/15 rabbits) were common signs. Abdominal ultrasonography and CT findings were suggestive of appendicitis in 6 of 8 rabbits and in 1 of 2 rabbits, respectively. Of the 6 rabbits that received medical treatment, 3 died at 48 hours, 1 died at 24 hours after hospitalization, and 1 died at 10 days after presentation; 1 rabbit was alive at 1,030 days after presentation. Of the 8 rabbits that underwent appendectomy, 3 died before discharge from the hospital and 1 died 113 days after surgery; 4 rabbits were alive at 315, 334, 1,433, and 1,473 days after presentation. The remaining 5 rabbits either died or were euthanized before treatment could be instituted. In each of the 19 rabbits, the appendix had evidence of severe inflammation with mucosal ulceration, heterophilic inflammation, and necrotic debris.CLINICAL RELEVANCE:For rabbits with decreased appetite and an apparently painful abdomen, hyperthermia, hypocalcemia, or hypoglycemia, appendicitis should be considered as a differential diagnosis. Further comparisons of medical and surgical treatments are required to establish treatment recommendations for rabbits with appendicitis.

The objective of this investigation was to compare the pharmacokinetics of metoclopramide (MET) after intraarterial (IA), intramuscular (IM), subcutaneous (SC), and perrectal (PR) administrations to normal rabbits. In this study, 6 normal New Zealand white rabbits were used in a random crossover design (4 × 4 Latin square) with a 1-week washout period between trials. Each rabbit had been administered MET at a dose of 2mg/kg IA, IM, and SC, and 4mg/kg PR. The plasma concentrations of MET were determined by high-performance liquid chromatography. The mean plasma profiles of MET after IA, IM, and SC administrations were similar. The bioavailability of MET when administered IM and SC was 96% and 112%, respectively. The plasma concentrations within the PR group were quite variable, resulting in an extremely low and variable bioavailability with an average of 12%. IM and SC administrations of MET may be useful in treating gastrointestinal disorders in rabbits when arterial or venous access is not available, but PR administration is likely to be unreliable.

In reptiles, administration of opioid drugs has yielded unexpected results with respect to analgesia. Tapentadol (TAP) is a novel atypical opioid drug labelled for human use. The objective of this study was to evaluate the pharmacokinetics and the pharmacodynamics of this drug in yellow-bellied sliders, after a single intramuscular (IM) injection of 5mg/kg of TAP. Turtles (n = 9) were randomly assigned to 2 treatment groups, according to a single-dose, single-treatment, unpaired, 2-period crossover design. Group A (n = 5) received a single IM (proximal front limb) dose of TAP (5mg/mL) at 5mg/kg. Group B (n = 4) received a single IM injection of saline (equivalent volume to opioid volumes) of TAP at the same site. After a 1-month washout period, groups were rotated and the experiment repeated. TAP plasma concentrations were determined by a validated high-performance liquid chromatography-fluorescence method, and an infrared thermal stimuli was applied to the plantar surface of the turtles’ hind limbs to evaluate the thermal withdrawal latency (TWL). TAP plasma concentrations were detectable between 1 and 24 hour(s) (1619 and 37ng/mL, respectively). The TAP-treated group showed an increase in TWL 1 hour after drug administration (13.32 ± 6.40 seconds). Subsequently, TWL decreased with time and significant differences between treatment and control groups were apparent up to 10 hours following treatment. A linear relationship (r2 = 0.99) between TAP plasma concentration and effect was found. Given these findings, TAP appears to be an attractive option for antinociception in turtles, owing to its rapid onset and acceptable duration of effect.

Enrofloxacin (E) is a commonly used antimicrobial in reptile medicine. However, few studies have been performed in reptile species to determine therapeutic blood levels of the fluoroquinolone (FQ) class of antimicrobial agents. The aim of the present study was to evaluate the pharmacokinetics of E and its metabolite ciprofloxacin (C) in 21 yellow-bellied slider turtles (Trachemys scripta scripta). The animals were administered 10mg/kg of E via intracoelomic injection. Blood was collected at scheduled times and analyzed using a validated high-performance liquid chromatography (HPLC) fluorescence method. The turtles showed some indications of transient pain following administration. The pharmacokinetics of E and C were long lasting (196 hours and 168 hours, respectively). This could be of concern where turtles are used for food because of drug tissue residues. The administered dose seemed to be optimal for clinical application because (1) drug concentrations in blood were appropriate for treating bacterial infections without adversely affecting the patient and (2) effective maximum concentration/minimum inhibitory concentration (Cmax/MIC) and area under the simulated blood-time curve (AUC)/MIC ratios were achieved. In conclusion, the dose of 10mg/kg administered via intracoelomic injection in yellow-bellied slider turtles appeared safe and achieved optimal pharmacodynamic parameters.

This article describes the clinical applicability of a nerve stimulator–guided technique, previously described in dogs, to block the sciatic and the femoral nerves in 4 pet rabbits (Oryctolagus cuniculus) undergoing hind limb surgeries. Preanesthetic intramuscular doses of medetomidine (0.08mg/kg), ketamine (15mg/kg), and buprenorphine (0.03mg/kg) were administered to the rabbit patients. The rabbits were intubated and general anesthesia was maintained using isoflurane in oxygen. The sciatic-femoral nerve block was performed with 2% lidocaine at a volume of 0.05mL/kg/nerve. Sciatic-femoral block was feasible in rabbits, and the motoric responses following electrical stimulation of both nerves were consistent with those reported in dogs after successful nerve location. Iatrogenic complications, namely nerve damage and local anesthetic toxicity, did not occur. Based on these results, the authors conclude that the sciatic-femoral nerve block described in dogs can be safely performed in rabbits. Clinical trials are required to assess the analgesic efficacy of the combined sciatic-femoral nerve block in rabbits as a part of multimodal pain management.