Assessment of biomarkers influencing treatment success on small intestinal lymphoma in dogs.

This study aimed to determine a reliable therapeutic biomarker for localized small intestinal lymphoma (SIL) in dogs based on clinical and histopathological features. We retrospectively investigated 84 dogs with localized SIL, including 36 dogs receiving surgery and 48 dogs receiving chemotherapy. The dogs receiving surgery were divided into two subgroups: 18 dogs (group 1) with overall survival (OS) <120 days (median OS) and 18 dogs (group 2) with OS ≥120 days. Correspondingly, the dogs receiving chemotherapy were divided into 24 dogs (group 3) with OS <98 days (median OS) and 24 dogs (group 4) with OS ≥98 days. Clinical, haematological, histopathological and immunohistochemical analyses were comparatively evaluated among the four subgroups. There was no significant difference in OS between the surgery and chemotherapy groups. In dogs receiving surgery, the rate of Ki67-positive cells was significantly increased in group 1 compared to group 2 and showed no significant difference between groups 3 and 4. In dogs receiving chemotherapy, the rate of O6-methylguanine-DNA methyltransferase (MGMT) was significantly higher in group 3 than in group 4 and showed no significant difference between groups 1 and 2. Additionally, our data showed that OS in dogs with higher Ki67 expression might be significantly increased by chemotherapy than by surgery, that of those with higher MGMT expression might be significantly increased by surgery than by chemotherapy, and Ki67 and MGMT were independent of each other. Indices of Ki67 and MGMT are suggested therapeutic biomarkers to determine the optimal first-line treatment for localized SIL in dogs.

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.

Boron neutron capture therapy (BNCT) as a new approach for clear cell sarcoma (CCS) treatment: Trial using a lung metastasis model of CCS.

Clear cell sarcoma (CCS) is a rare malignant tumor with a poor prognosis. In the present study, we established a lung metastasis animal model of CCS and investigated the therapeutic effect of boron neutron capture therapy (BNCT) using p-borono-L-phenylalanine (L-BPA). Biodistribution data revealed tumor-selective accumulation of (10)B. Unlike conventional gamma-ray irradiation, BNCT significantly suppressed tumor growth without damaging normal tissues, suggesting that it may be a potential new therapeutic option to treat CCS lung metastases.

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.

The use of micro-computed tomography in the diagnosis of dental and oral disease in rabbits.

BACKGROUND: The aim of this study was to investigate the use of a newly developed micro-computed tomography (micro-CT) system for the diagnosis of oral pathologies in small animals, using the rabbit as a model. The diagnosis of dental diseases in rabbits is usually based on oral endoscopy and radiographic imaging, but detailed pathological diagnosis using these methods is frequently difficult. Micro-CT was used in this study to address this challenge. RESULTS: This study was conducted using 50 privately owned rabbits, presented to our hospital due to loss of appetite or difficulty feeding. Image recording times were 18 s in normal mode and 120 s in fine mode. The animals were maintained in the required position for scanning via the administration of sedatives. Micro-CT captured with a slice thickness of 60-120 mm has excellent spatial resolution, and is suitable for the clinical diagnosis of dental diseases in rabbits weighing 1-3 kg. CONCLUSIONS: Micro-CT can yield more detailed data than radiography or conventional CT. This study determined that this novel imaging modality can be utilized for the accurate assessment of dental and oral diseases in rabbits.

Spontaneous Extraskeletal Osteosarcoma in a Rabbit (Oryctolagus cuniculus): Histopathological and Immunohistochemical Findings.

A spontaneously occurring subcutaneous mass in the left forelimb of a nine-year-old rabbit (Oryctolagus cuniculus) was examined histopathologically and immunohistochemically. Clinically, edema and hemorrhage were seen around the mass. No connection of the tumor mass to the appendicular skeleton was found. The tumor was arranged in a solid growth pattern and irregular bundles, and neoplastic cells were polygonal to spindle-shape. Osteoid (positive for osteocalcin) and multinucleated giant cells were diffusely or focally seen. Neoplastic cells were positive for vimentin, osterix and Ki-67, indicating the nature of osteoblasts with proliferating activity, but negative for α-smooth muscle actin, desmin or CD204. Based on these findings, a diagnosis of extraskeletal osteosarcoma was made, a very rare tumor both in laboratory and pet rabbits.

Combined hepatocellular-cholangiocarcinoma in a Yellow-headed Amazon (Amazona oratrix).

A 9-year-old male Yellow-headed Amazon (Amazona oratrix) with a history of anorexia and vomiting died of a liver tumor. The tumor consisted of neoplastic cells with hepatocellular and cholangiocellular differentiations and their intermingled areas. Neoplastic hepatocytes showed islands or trabecular growth with vacuolated eosinophilic cytoplasm. Cells showing biliary differentiation formed ducts or tubules lined by cytokeratin AE1/AE3-positive epithelia, accompanied by desmoplasia consisting of myofibroblasts reacting to α-smooth muscle actin and desmin. The tumor was diagnosed as a combined hepatocellular-cholangiocarcinoma, which is very rare in the avian.

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.

Successful management with CHOP for pulmonary lymphomatoid granulomatosis in a dog.

A 3-year-old, spayed female miniature dachshund was presented for vomiting and anorexia. Thoracic radiographs and CT scan revealed abnormal pulmonary opacities at bilateral caudal lobe. Cytological analysis of the pulmonary mass revealed the presence of large lymphohistiocytic cells and small lymphocytes with occasional neutrophils and plasma cells. An open lung biopsy was performed and a diagnosis of pulmonary lymphomatoid granulomatosis (LYG) was made. The dog was administered CHOP based therapy (modified UW-25), and it survived for 1,022 days after admission. Immunohistochemistry revealed pulmonary lesions consisted of many CD79a positive B cells aggregation and proliferation with prominent angiocentric pattern. This was the first case of canine pulmonary LYG managed by CHOP chemotherapy.

Neoplasitic diseases in ferrets in Japan: a questionnaire study for 2000 to 2005.

The objective of this study was to collect epidemiological data on neoplasms in pet ferrets in Japan. A questionnaire to collect information was made available to Japanese veterinary practitioners through the web site of the Japanese Society of Exotic Pet Medicine. Completed questionnaires were returned from 29 practices, and 945 neoplasms met the criteria for inclusion in the study. Neoplasms were found in every organ system except the respiratory system; the endocrine (418; 44.2%), integumentary (196; 20.7%) and hemolymphatic (184; 19.5%) systems were most commonly affected. The most common tumor types were pancreatic islet cell tumor (211: 22.3%), adrenal gland tumor (207; 21.9%) and lymphoma (152; 16.1%). The age of the affected ferrets ranged from less than 3 months to more than 7 years of age. Tumor incidence was highest in ferrets between 4 and 6 years of age. No sex predilection was found. These results were similar to those recently published in North America. Most Japanese pet ferrets are imported from North America, and their husbandry including diets is similar to that in North America, which may explain the similar tendencies in the incidence of neoplasms in this study and those of findings in North America.

Adrenal diseases in ferrets in Japan.

Adrenal diseases are quite common in Japanese pet ferrets; however, there have been no reports concerning the epidemiology of ferret adrenal disease in Japan. The purpose of this study was to collect epidemiological data on ferret adrenal disease in Japan by sending a questionnaire to veterinarians throughout Japan. Among the 521 cases that met the criteria for this study, 307 were adrenocortical carcinoma (58.9%), 117 were adrenocortical adenoma (22.5%) and 87 were adrenocortical hyperplasia (16.7%), respectively. Sex, clinical signs, concurrent diseases, age and the sites of the affected adrenal gland in these cases were similar to those reported in North America. Most pet ferrets in Japan are imported from North America, and their husbandry in Japan is similar to that in North America, which may be the cause of the similarity in ferret adrenal disease between North America and Japan. Because a difference in the incidence of ferret adrenal diseases among countries has been reported, further research is necessary to investigate the factors related to the similarities and how to decrease the incidence of adrenal diseases in ferrets in Japan.

Spontaneous adenocarcinoma immunoreactive to cyclooxygenase-2 and transforming growth factor-beta1 in the buccal salivary gland of a Richardson's ground squirrel (Spermophilus richardsonii).

The ground squirrel is used as an experimental animal because of its unique biological nature. A 3-year-old female Richardson's ground squirrel developed a mass, 1.5 cm in diameter, in the buccal mucosa. The mass consisted of neoplastic epithelial cells showing acinar, ductular, intraductal papillary, solid, and lobular growth patterns; the cells were immunoreactive to cytokeratin, cyclooxygenase-2 (a marker of malignancy) and TGF-beta1. After resection, the tumor recurred with increased area having a solid or lobular pattern with little differentiation. This tumor was diagnosed as an adenocarcinoma arising from the buccal gland, the first case reported in the ground squirrel. A prominent desmoplastic reaction was present. The interstitial cells reacted to alpha-smooth muscle actin and vimentin, indicating a myofibroblastic nature, presumably induced by epithelial TGF-beta1.

Gastric adenocarcinoma with ossification in a ferret (Mustela putorius furo).

A 6-year-old female ferret had a firm mass 2 cm in diameter in the pyloric region of the stomach. Histopathologically, the mass was composed of neoplastic proliferation of well-differentiated epithelial cells, showing tubular or glandular growth patterns. Osseous metaplastic foci were often found in the tumor. Tumor cells showed a positive reaction for immunohistochemistry against bone morphogenetic protein-6, an osteogenic factor. A diagnosis of gastric adenocarcinoma with ossification was made.