Retrospective analysis of liver lobe torsion in pet rabbits: 40 cases (2016–2021)

Abstract

Background: Liver lobe torsion (LLT) in rabbits can be under-recognised and potentially fatal. The clinical features of cases presented to an exotic animal veterinary service in Australia were retrospectively reviewed. Method: Medical records of confirmed rabbit LLT cases between 2016 and 2021 were reviewed for signalment, clinical signs and findings, diagnostic imaging results, management strategies and outcomes. Variables of interest were analysed for statistical association with outcome. Results: A total of 40 rabbits were included. The mean presenting age was 56.2 months (SD 30.5). Neutered males (23/40, 57.5%) were over-represented. Common clinical signs and findings included reduced appetite (40/40, 100%), lethargy (32/40, 80.0%), reduced faecal production (16/40, 40.0%), a doughy distended stomach (20/40, 50.0%), pale mucous membranes (19/40, 47.5%) and hypothermia (17/40, 42.5%). Anaemia and elevated plasma alanine aminotransferase and blood urea nitrogen were common clinicopathologic findings. Computed tomography (CT) was performed in 34 of 40 rabbits, confirming the presence and position of LLT (34/34, 100%), stenosis of the caudal vena cava or portal system (28/34, 82.4%) and increased free peritoneal fluid (29/34, 85.3%). Fifteen (15/40, 37.5%) rabbits were medically managed, and surgical intervention was performed in 23 of 40 (57.5%) rabbits. Overall, 30 of 40 (75.0%) rabbits survived. Surgical intervention did not confer a significant difference in outcome compared to medical management (odds ratio 0.77, 95% confidence interval 0.15-4.10, p = 0.761). Conclusion:CT can be an invaluable diagnostic modality for rabbit LLT. Favourable outcomes can be achieved in selected cases with medical management alone.

Left medial liver lobe torsion and postoperative acute gastric rupture in a 2.5‐year‐old male‐castrated Flemish Giant rabbit (Oryctolagus cuniculus)

“…An alternative differential is increased vascular permeability, for example, secondary to SIRS or thromboembolic disease. 4 Reported less common perioperative complications include fatal hemorrhage, cardiopulmonary arrest, hypotension, hypothermia, and arrhythmias. 8 No cases of acute gastric rupture have been recorded as a perioperative complication associated with hepatic lobectomy in rabbits.…”

“…Hepatic lobectomy with appropriate perioperative supportive care has been widely described as the treatment of choice for LLT with good prognosis, infrequent postoperative complications, and a longer survival time versus medical management alone 2–9 . However, in several studies, there was no statistically significant difference in overall outcome between surgical and medical management of LLT in rabbits 4,8 . The most common complication of LLT is recurrent episodes of RGIS, 2,6 which is reported more frequently in medically managed cases than surgically 6 .…”

“…[2][3][4][5][6][7][8]10 Right lateral, right medial, left lateral, and LLT affecting multiple liver lobes (right lateral/left lateral, right lateral/caudate) have been described as occurring more infrequently. [2][3][4][5][6][7][8]10 However, no cases of left medial LLT have been described within the literature.…”

“…Acute LLT is a medical emergency, with death reported to occur as rapidly as 12-72 h from onset of clinical signs in some cases, 3 with common complications including hemoabdomen, systemic inflammatory response syndrome (SIRS), disseminated intravascular coagulopathy (DIC) and acute-death. 2,4,7 Chronic LLT have also been reported, often discovered incidentally at necropsy, with clinically affected individuals being asymptomatic or showing nonspecific low-grade signs of RGIS and/or abdominal pain. 3,6 Common clinical signs and clinical examination findings reported with LLT include lethargy, 2,3,5,9,10 altered mentation, 3,5,7 symptoms of RGIS 3,4,6 (e.g., hypo-/anorexia, 2,3,5,7,9,10 decreased fecal output, 2,5 doughy distended stomach, 4 diarrhea 5 ), cranial abdominal pain, 2-7,9,10 cranial abdominal mass effect, 2,6,7 jaundice, 9,10 pale mucous membranes, 3,4,7,10 tachycardia, 7 tachypnoea, 7 decreased skin turgor, 4 and hypothermia.…”

“…2,3,5,10 Ultrasonography is considered the gold standard imaging modality for diagnosing LLT in rabbits. 2 Commonly described findings include hyperechoic falciform fat, 2,[4][5][6] focal lobar/generalized hepatomegaly, 2,3,5,6 rounded hepatic lobar margins, 2,3,4,6 and decreased/mixed hepatic parenchymal echogenicity. 2-6,9,10 Disruption of the vasculature of the affected liver lobe can also be identified sonographically, with decreased blood flow on Colour Doppler.…”