OBJECTIVE: To document clinicopathologic findings in domestic rabbits with liver lobe torsion and identify prognostic factors. ANIMALS: 82 rabbits. PROCEDURE: Medical records of 4 institutions were reviewed to identify rabbits with an antemortem diagnosis of liver lobe torsion that were examined between 2010 and 2020. RESULTS: The prevalence of liver lobe torsion was 0.7% (82/11,402). In all 82 rabbits, the diagnosis was made by means of abdominal ultrasonography. Fifty (60.1%) rabbits underwent liver lobectomy, 23 (28%) received medical treatment alone, and 9 (10.9%) were euthanized or died on presentation. Overall, 32 (39%) rabbits died within 7 days of initial presentation and 50 (61%) survived. Seven-day survival rate did not differ significantly between medical treatment alone and surgical treatment. However, median survival time following medical treatment (530 days) was shorter than that following surgical treatment (1,452 days). Six of 14 rabbits had evidence of systemic inflammatory disease on necropsy. Rabbits with right liver lobe torsion were less likely to survive for 7 days than were those with caudate torsions (P = 0.046; OR, 3.27; 95% CI, 1.04 to 11.3). Rabbits with moderate to severe anemia were less likely to survive for 7 days than were rabbits that were not anemic or had mild anemia (P = 0.006; OR, 4.41; 95% CI, 1.55 to 12.51). Other factors associated with a decreased 7-day survival rate were high heart rate at admission (P = 0.013) and additional days without defecation after admission (P < 0.001). Use of tramadol was associated with an increased survival rate (P = 0.018). CLINICAL RELEVANCE: The prognosis for rabbits with liver lobe torsions was more guarded than previously described. Rabbits that underwent liver lobectomy had a longer median survival time than did rabbits that only received medical treatment.

One of the most common presenting complaints in rabbits is decreased food intake and/or fecal output. This can occur as a clinical consequence of pain, anesthesia and systemic or gastrointestinal disease. In conjunction with diagnosing and treating the underlying condition, veterinary care should aim to normalize food intake and fecal output. Mirtazapine is a tetracyclic antidepressant that has appetite stimulating effects in other species. However, studies in rabbits are currently lacking. Nine six-month old, intact (4 male, 5 female) New Zealand White rabbits (Oryctolagus cuniculus) were used in a randomized, blinded, controlled, complete cross-over experiment. Each rabbit received a low-dose of mirtazapine (1 mg/kg), high-dose (3 mg/kg) and control treatment orally once a day for a total of 2 sequential days with a 5- day washout period between treatment groups. Fecal output, food intake and body weight were measured before, during and after treatment. Fecal output was 25% higher (95% CI: 6.3%–46.9%, P= 0.01) on treatment days following high-dose mirtazapine treatment. Body weight was 1.5% higher (95% CI: 0. 5% to 2.6%, P= 0.006) for all groups on the 2 days following treatment compared to baseline. Body weight was reduced by 2.1% (95% CI: -3.6% to -0.6%, P= 0.011) the week following high-dose mirtazapine treatment. Mirtazapine did not have a statistically significant effect on food intake. Oral administration of mirtazapine at 3 mg/kg once a day resulted in increased fecal output but not a concurrent increase in food intake. Overall, mirtazapine is well tolerated and may be a useful treatment to increase fecal output in rabbits. However, due to a mild reduction in weight following treatment, clinical monitoring is warranted.

OBJECTIVE: To describe the clinical features, histopathologic lesions, and outcome of cardiovascular disease in central bearded dragons. ANIMALS: 54 bearded dragons. METHODS: Retrospective evaluation of captive bearded dragons with antemortem imaging or postmortem diagnosis of cardiovascular disease from 2007 to 2022 from 6 hospitals. RESULTS: The total prevalence of cardiovascular disease was 3.3% (54/1,655). Physical examination findings were available in 46 cases with change in mentation being the most common finding (n = 28/46 [60.9%]), followed by dehydration (17/46 [37%]), palpable coelomic mass (13/46 [28.3%]), dyspnea (10/46 [21.7%]), and sunken eyes (10/46 [21.7%)]. Doppler auscultation revealed an arrhythmia in 5/34 (14.7%) animals. Diagnostic imaging was only performed on 21 animals, and 10 (47.6%) had cardiovascular abnormalities described. In total, 84 cardiovascular diagnoses were found in 54 animals. The most common diagnosis was myocarditis (n = 14) followed by aneurysms (11), pericardial effusion (9), atherosclerosis (7), epicarditis (7), and myocardial degeneration/necrosis (7). Overall, 62 causes of death were identified in 52 cases, with cardiovascular disease being the most common (n = 18/52 [34.5%]). Only 3/54 animals were diagnosed with congestive heart failure. Animals with aneurysms were more likely to die to due cardiovascular disease compared to other types of cardiovascular diagnoses (OR, 43.75; 95% CI, 4.88 to 392.65; P < .001). CLINICAL RELEVANCE: Diagnosis of cardiovascular disease in bearded dragons is challenging given the inconsistent clinical presentation; however, it should remain a differential in animals with nonspecific signs of illness. Antemortem diagnostics are recommended in suspected cases, including diagnostic imaging. Of the cardiovascular diseases described, aneurysms most often contributed to clinical demise.

Objective: To evaluate the major crossmatch compatibility between rabbit recipients, rabbit donors, and the major canine and feline blood types.Design: Prospective in vitro study in December 2021.Setting: Academic veterinary teaching hospital.Animals: Whole blood samples were collected from 11 healthy New Zealand White rabbits (Oryctolagus cuniculus) with no previous transfusion history. Three pigtail segments were acquired from dog erythrocyte antigen (DEA)‐1‐positive, DEA‐1‐negative, and feline type A blood units. Whole blood was collected from a healthy type B blood donor cat.Interventions: Blood from each rabbit recipient underwent a major crossmatch using standard tube crossmatch methodology with itself and the following donor blood types: rabbit, DEA‐1‐positive, DEA‐1‐negative, feline type A, and feline type B.Measurements and Main Results: Self‐crossmatches and crossmatches between rabbit recipients and conspecific donors were negative for hemolysis and agglutination. Crossmatches between rabbit recipients and canine and feline donors yielded no hemolysis but produced varying degrees of macroscopic and microscopic agglutination. Rabbit recipients had 1.4 (95% confidence interval: 1.1–1.8) times the risk of macroscopic agglutination when major crossmatched with canine blood compared to feline blood. No significant difference in agglutination was found between DEA‐1‐positive and DEA‐1‐negative or feline type A and type B donors.Conclusions: These findings support allogeneic blood transfusions between rabbits being highly compatible and suggest rabbits have naturally occurring alloantibodies against both canine and feline red blood cells. However, feline red blood cells had a lower rate of in vitro incompatibility on major crossmatch, suggesting potentially higher in vivo compatibility if an emergency xenotransfusion is needed. Further prospective research is needed to determine if xenotransfusion is associated with a higher incidence of acute and delayed transfusion reactions in rabbits than allogeneic transfusions.