Rabbit Soft Tissue Surgery

Comparison between Carprofen and Meloxicam for Post-Neutering Pain Management in Pet Rabbits

Surgical neutering in pet rabbits is common practice to prevent reproduction and associated health issues. Adequate postoperative pain management is crucial for recovery, yet effective methods in clinical settings remain underexplored. This study compared the analgesic effects of carprofen and meloxicam in pet rabbits undergoing surgical neutering. Fifty rabbits of varied demographics were included, with pain assessed using the Centro Animali Non Convenzionali Rabbit Scale (CANCRS). Rabbits were allocated to receive postoperative 2 mg kg-1 carprofen or 1 mg kg-1 meloxicam by subcutaneous injection. Anesthesia was induced with an intramuscular combination of ketamine (20 mg kg-1), medetomidine (0.4 mg kg-1), and butorphanol (0.2 mg kg-1), and ovariectomy or orchiectomy were performed. The CANCRS scale was used to assess pain by evaluating the rabbit preoperatively, 6 h postoperatively, and at three time points the following day. Times of return to spontaneous feeding and fecal production were also recorded. No statistically significant difference was found between treatment groups based on CANCRS scores and resumption of food intake and fecal output. No clinically detectable adverse effects were noted. While limitations include the use of a single pain assessment scale and the absence of a placebo control group, the results suggest that both carprofen and meloxicam can be viable options in clinical practice. Further research utilizing diverse pain assessment methods is warranted to enhance understanding and optimize pain management strategies for rabbits undergoing surgical procedures.

Effects of Intratesticular Lidocaine in Pet Rabbits Undergoing Orchiectomy

The use of local anesthetics for castration is both simple and cost-effective, and it may contribute to reducing the anesthetic requirements. Despite its common use in clinical practice, the literature regarding the effects of intratesticular lidocaine in rabbits is limited. In this study, nine rabbits per group were assigned to intratesticularly receive either 2% lidocaine (0.05 mL/kg into each testicle) or an equivalent volume of saline prior to elective orchiectomy. Anesthesia was induced by intranasal administration of ketamine, medetomidine, and butorphanol. During intraoperative assessment, no significant differences in vital parameters (heart rate, respiratory rate, and peripheral saturation of oxygen) were observed between the groups. However, rabbits receiving intratesticular saline displayed a higher incidence of responses to surgical stimuli. Postoperative pain was evaluated using the composite Centro Animali Non Convenzionali Rabbit Scale (CANCRS), revealing a significantly lower score at the initial post-surgery assessment in rabbits treated with intratesticular lidocaine. All subjects exhibited rapid resumption of food intake and fecal output. While all rabbits demonstrated satisfactory perioperative performances, the use of intratesticular lidocaine was associated with a diminished response to surgical stimuli. Consequently, this practice has the potential to reduce the requirement for additional anesthetics or analgesics, promoting faster recovery.

Comparison of conventional ligatures and a vessel sealing device for haemostasis during open ovariohysterectomy in rabbits

AIMS

To compare surgical times and rates of intra-operative and post-operative complications for open ovariohysterectomy (OVH) in female rabbits using conventional ligatures or a vessel sealing device (VSD) for haemostasis.

METHODS

Female pet rabbits (n = 23) presented for OVH for either desexing or treatment of reproductive disorders were randomly assigned to a conventional ligatures (CL) group (n = 12) or a LigaSure 5-mm (LS5) group (n = 11). In the CL group, the ovarian pedicles were ligated with a single surgeon's knot. After transection of the ovarian pedicles, the broad ligament was manually broken down along the uterine horns to their respective cervices. In the LS5 group, both ovarian pedicles and the broad ligaments were sealed with a LigaSure Dolphin Tip VSD with 5-mm forceps. All the rabbits were hospitalised for 24 hours after surgery. Two weeks after discharge, a clinical recheck examination was performed. Incision length, overall surgical time (from initial incision to completion of intradermal suturing), OVH time (from identification of the first ovary to transection of the vaginal vault), and intra- and post-operative complications were recorded and compared between groups, using the Student's t-test for normally distributed continuous data, the Wilcoxon-Mann-Whitney test for non-normally distributed continuous data and Pearson's χ2 test for categorical data.

RESULTS

The mean overall surgical time was 14.1 (SD 4.4) minutes. The surgery took 15.0 (SD 4.9) minutes in the CL group and 13.1 (SD 3.8) minutes in the LS5 group (p=0.10). The OVH time was shorter in the LS5 group (mean 4.2 (SD 0.9) minutes) than in the CL group (mean 6.3 (SD 1.7) minutes; p = 0.005). No intra-operative complications were encountered in the LS5 group. Haemorrhage occurred in three rabbits in the CL group. One rabbit in the LS5 group developed steatonecrosis post-operatively. There was no evidence of a difference in the proportion of rabbits that experienced intra- and post-operative complications (p = 0.25 and p = 0.94 respectively) between groups.

CONCLUSIONS

The use of a LigaSure 5-mm VSD and conventional ligatures during open OVH were both associated with similar overall surgical times and complication rates. The OVH times were shorter in the LS5 group compared to the CL group.

CLINICAL RELEVANCE

Use of the LigaSure 5-mm VSD allows efficient haemostasis while performing open OVH in female pet rabbits.

Paracostal versus ventral midline approach for caudate liver lobectomy in the rabbit

Objective

To describe the paracostal approach to caudate liver lobectomy in rabbits and compare the outcome of paracostal versus ventral midline approach for caudate liver lobectomy in rabbits with caudate liver lobe torsion (LLT).

Study design

Cadaveric and retrospective study.

Animals

Normal rabbit cadavers (n = 5) and rabbits with caudate LLT (n = 22).

Methods

Cadavers – a right paracostal or ventral midline approach was made. Accessibility of the caudate liver lobe and relationship to the gastrointestinal (GI) tract were assessed. Clinical LLT cases – 9 cases were treated via the paracostal approach and 13 were treated via the ventral midline approach. Medical records (January, 2018 to October, 2021) were reviewed. Anesthesia and surgical times, mortality rate, and relevant clinical data were compared between groups.

Results

In cadavers, caudate liver lobectomy was feasible through a paracostal approach without retraction of the GI tract. In clinical cases, there was no difference in anesthesia time (P = 0.1397) or surgical time (P = 0.9462) between groups. All rabbits that underwent paracostal approach survived to discharge. Mortality was lower (P = .053) and postoperative time until eating was shorter (P = .0238) for patients undergoing paracostal approach.

Conclusion

Rabbits experienced lower mortality and shorter time until eating when treated through a right paracostal approach compared to the ventral midline approach. The paracostal approach resulted in minimal to no manipulation of the GI tract.

Clinical significance

A right paracostal approach for caudate liver lobectomy in rabbits provides good exposure while avoiding GI tract manipulation. This approach may result in improved survival and earlier eating in rabbits with caudate LLT.

Computed tomography with Hounsfield unit assessment is useful in the diagnosis of liver lobe torsion in pet rabbits (Oryctolagus cuniculus)

Clinical signs of liver lobe torsion in rabbits are often nonspecific and mimic those that are also generally detected with gastrointestinal stasis. Nonspecific clinical signs may result in pursuit of full-body imaging such as computed tomography (CT). The aim of this multicenter, retrospective, case series study was to describe CT findings of liver lobe torsion in a group of rabbits. Computed tomography studies of six rabbits with confirmed liver lobe torsion by surgery or necropsy were evaluated. The caudate liver lobe was affected in six out of six rabbits and was enlarged, rounded, hypoattenuating, heterogeneous, and minimally to noncontrast enhancing, with scant regional peritoneal effusion. Precontrast, mean Hounsfield units (HU) of the torsed liver lobe (39.3 HU [range, 24.4-48.1 HU]) were lower than mean HU of normal liver (55.1 HU [range, 49.6-60.8 HU]), with a mean torsed:normal HU ratio of 0.71 (range, 0.49-0.91). Postcontrast, mean HU of the torsed liver lobe (38.4 HU [range, 19.7-48.9 HU]) were also lower than mean HU of normal liver (108.4 HU [range, 84.5-142.0 HU]), with a lower postcontrast mean torsed:normal HU ratio of 0.35 (range, 0.14-0.48) compared to precontrast. Mean HU of torsed liver lobes had little difference pre- and postcontrast (postcontrast HU 1.0 times the average precontrast HU [range, 0.81-1.1]), and contrast enhancement of the torsed liver lobes was on average 50% lower than in normal liver. Liver lobe torsion should be considered in rabbits with an enlarged, hypoattenuating, heterogeneous, minimally to noncontrast enhancing liver lobe, particularly the caudate lobe, and scant regional peritoneal effusion.

A Robotic Biopsy Endoscope with Magnetic 5-DOF Locomotion and a Retractable Biopsy Punch

Capsule endoscopes (CEs) have emerged as an advanced diagnostic technology for gastrointestinal diseases in recent decades. However, with regard to robotic motions, they require active movability and multi-functionalities for extensive, untethered, and precise clinical utilization. Herein, we present a novel wireless biopsy CE employing active five degree-of-freedom locomotion and a biopsy needle punching mechanism for the histological analysis of the intestinal tract. A medical biopsy punch is attached to a screw mechanism, which can be magnetically actuated to extrude and retract the biopsy tool, for tissue extraction. The external magnetic field from an electromagnetic actuation (EMA) system is utilized to actuate the screw mechanism and harvest biopsy tissue; therefore, the proposed system consumes no onboard energy of the CE. This design enables observation of the biopsy process through the capsule's camera. A prototype with a diameter of 12 mm and length of 30 mm was fabricated with a medical biopsy punch having a diameter of 1.5 mm. Its performance was verified through numerical analysis, as well as in-vitro and ex-vivo experiments on porcine intestine. The CE could be moved to target lesions and obtain sufficient tissue samples for histological examination. The proposed biopsy CE mechanism utilizing punch biopsy and its wireless extraction-retraction technique can advance untethered intestinal endoscopic capsule technology at clinical sites.

Rabbit Neutering in Primary-Care Education: Insights from a Surgical Clinic

Involvement in canine and feline surgical neutering clinics is generally considered to be a key element of primary-care veterinary education, yet opportunities for veterinary students to develop their surgical skills with rabbit patients are uncommon. This is despite the fact that rabbits are currently estimated to be the third most popular companion animal species and the fact that the British Small Animal Veterinary Association (BSAVA) recommends that all non-breeding rabbits be neutered soon after they attain sexual maturity. We describe a pilot rabbit-neutering clinic designed to provide high-quality care for rabbit patients while offering opportunities for undergraduate surgical and case-management skills development. We report on the clinical outcomes for patients. Rates of morbidity (n=18) and mortality (n=1) were low. Of complications reported, the majority (n=16) were considered minor. Challenges included ensuring that staff and students were trained in the specific features of rabbit anesthesia and recovery behavior. We conclude that rabbit surgical clinics offer excellent learning opportunities for undergraduate veterinary students. With prior training in handling and close individual supervision, it is possible to achieve good clinical outcomes and to have a positive impact on the welfare of companion animal populations.