Outcome of limb fracture repair in rabbits: 139 cases (2007-2015).

OBJECTIVE To evaluate outcome of limb fracture repair in rabbits. DESIGN Retrospective case series. ANIMALS 139 client-owned rabbits with limb fractures treated between 2007 and 2015. PROCEDURES Medical records were reviewed for information on fracture location, fracture treatment, and time to fracture healing. RESULTS 25 rabbits had fractures involving the distal aspects of the limbs (ie, metacarpal or metatarsal bones, phalanges, and calcaneus or talus). Fractures were treated in 23 of these 25 rabbits (external coaptation, n = 17; external skeletal fixation, 4; and intramedullary pinning, 2) and healed in all 23, with a median healing time of 28 days (range, 20 to 45 days). One hundred ten rabbits had long bone fractures, and fractures were treated in 100 of the 110 (external skeletal fixation, n = 89; bone plating, 1; intramedullary pinning, 3; and external coaptation, 7). The percentage of fractures that healed was significantly lower for open (14/18) than for closed (26/26) tibial fractures and was significantly lower for femoral (19/26) and treated humeral (4/6) fractures than for radial (23/24) or closed tibial (26/26) fractures. Micro-CT was used to assess fracture realignment during external skeletal fixator application and to evaluate fracture healing. CONCLUSIONS AND CLINICAL RELEVANCE The prognosis for rabbits with limb fractures was good, with fractures healing in most rabbits following fracture repair (109/123). Micro-CT was useful in assessing fracture realignment and evaluating fracture healing.

Characteristics of bone fractures and usefulness of micro-computed tomography for fracture detection in rabbits: 210 cases (2007-2013).

OBJECTIVE: To characterize bone fractures and the usefulness of micro-CT for imaging fractures in pet rabbits. DESIGN: Retrospective case series. ANIMALS: 210 client-owned rabbits with bone fractures. PROCEDURES: Medical records of rabbits evaluated for bone fractures from 2007 through 2013 were examined. Information was collected on signalment and nature of fractures, and radiographic and micro-CT images of fractures were reviewed. RESULTS: Almost half (n = 95 [47.7%]) of fractures were in rabbits < 3 years old. Accidental fall was the most common cause. Vertebral fracture was the most common type of fracture with a nonneoplastic cause (n = 46 [23.2%]) and was most common in the L4-L7 region. The tibia was the most common site for limb fracture among all fractures with a nonneoplastic cause (45 [22.7%]). Twelve (5.7%) fractures had a neoplastic cause, and 7 of these were associated with metastatic uterine adenocarcinoma. Females were significantly more likely to have a fracture caused by neoplasia than were males. Compared with radiography, micro-CT provided more detailed fracture information, particularly for complicated fractures or structures (eg, skull, pelvic, vertebral, and comminuted limb fractures). CONCLUSIONS AND CLINICAL RELEVANCE: Findings were useful for understanding the nature of fractures in pet rabbits and supported the use of micro-CT versus radiography for fracture detection and evaluation.

A collision tumor consisting of granular cell tumor and adenocarcinoma in the uterus of an aged djungarian hamster.

A neoplastic nodular lesion consisting of an admixture of granular cell tumor and adenocarcinoma was found in the uterus of a 26-month-old Djungarian hamster. Neoplastic cells of the uterine adenocarcinoma showed an epithelial nature in their growth patterns and by cytokeratin-immunopositive reaction, exhibiting nuclear pleomorphism. The granular cells had an abundant amount of fine granular eosinophilic cytoplasm and eccentric or central nuclei with no nuclear atypia; the granular structures were positive for periodic acid-Schiff with diastase resistance and were confirmed as lysosomes/autophagosomes by electron microscopy; immunohistochemically, the cells reacted to desmin, vimentin and α-smooth muscle actin and negatively for neurogenic, histiocyte/macrophage or epithelial markers, indicating smooth muscle origin. Because these tumors were generated from different cell origins, a diagnosis of collision tumor was made.

Neuritogenic effects of T cell-derived IL-3 on mouse splenic sympathetic neurons in vivo.

To determine the role played by lymphocytes and cytokines in the growth of sympathetic neurons in vivo, the innervation and cytokine levels were examined in the spleens of SCID mice that lack T and B cells. Splenic noradrenaline, nerve growth factor (NGF), and IL-1beta levels were elevated in SCID mice. Immunohistochemical examination revealed that the density of tyrosine hydroxylase-positive (TH(+)) fibers of splenic central arteries in SCID mice was increased compared with wild-type C.B-17 mice, while SCID mice had significantly fewer TH(+) fibers in their periarteriolar lymphatic sheaths (PALS). Two weeks after SCID mice were injected with C.B-17 splenic T cells, their TH(+) fiber staining increased in the PALS. IL-3 levels increased significantly in SCID mice following T cell reconstitution, and the administration of anti-IL-3 Ab blocked the above T cell-induced increase in innervation in the PALS. Anti-IL-3 treatment also inhibited the regeneration of splenic sympathetic neurons in C.B-17 mice after they were chemically sympathetomized with 6-hydroxydopamine. Depletion of NK cells by anti-asialo GM1 promoted the splenic innervation in SCID mice, while there were no significant changes in the innervation between CD8(+) T cell-deficient beta(2)-microglobulin knockout mice and their wild type. Our results suggest that T cells (probably CD4(+) Th cells but not CD8(+) CTLs) play a role in regulating the sympathetic innervation of the spleen; this effect appeared to be mediated, at least in part, by IL-3. On the contrary, NK cells may exert an inhibitory effect on the sympathetic innervation.