Young Female Beagle Dogs Research Articles

Histiocytic typhlocolitis in two colony Beagle dogs

Two young female Beagle dogs in a laboratory colony with clinical signs of loose stools and fecal blood were confirmed to have histiocytic ulcerative colitis by histologic evaluation. This syndrome is well recognized in other dog breeds such as Boxers and related French Bulldogs, Mastiffs, Alaskan malamutes and Doberman Pinschers. Formalin-fixed paraffin sections of large intestine from one dog demonstrated the presence of Escherichia coli strain LF82 by immunohistochemistry and 16S ribosomal RNA gene sequencing. E coli strain LF82 has been implicated in the pathogenesis of Crohn's disease and similar bacteria have been cultured from cases of histiocytic ulcerative colitis in Boxer dogs. Spontaneous histiocytic ulcerative colitis must be differentiated from test article-related findings in nonclinical toxicity studies in Beagle dogs.

Relative bioavailability of danazol in dogs from liquid-filled hard gelatin capsules

Danazol was dissolved in non-aqueous mixtures containing either polyethylene glycol 400 or polysorbate 80, and filled into hard gelatin capsules at 50 mg concentrations. The bioavailability of these formulations was compared with commercial danazol capsules in a two-way crossover study using young female beagle dogs. Both formulations showed greater oral bioavailability when compared with either the 100 or 200 mg commercial brand of danazol. The bioavailability of the polyethylene glycol 400 and polysorbate 80 formulations was enhanced 3.7 and 15.8 times, respectively, when compared at the 100 mg dose level.

Subchondral bone remodeling increases in early experimental osteoarthrosis in young beagle dogs.

We evaluated subchondral bone remodeling and structure in the condyles of the femur and the patellar surface of the femur in early experimental osteoarthrosis of young female beagle dogs. 14 littermate (twin) dogs were divided into operation (n 7) and control groups (n 7). The dogs in the operation group underwent surgically a 30 degrees valgus angulation of the right tibia to induce osteoarthrotic articular cartilage lesions in the knee (stifle) joint. 7 months postoperatively, bone samples were harvested from both condyles and the patellar surface of the femur and evaluated by histomorphometry of subchondral bone. Cartilage samples from the same areas were taken for histology. In the operated dogs, subchondral bone remodeling increased strikingly in the patellar surface of the femur; osteoid thickness and osteoblast surface/bone surface increased up to 42% and 94% (p < 0.05), as compared to controls. Total and active erosion depths increased by 14% and 30% in the same area (p < 0.05). However, in bone structural parameters no significant difference could be observed between the groups. In the medial condyle of the femur, the trabecular number decreased in operated dogs, as compared to controls (p < 0.05). The lateral condyle of the femur in operated animals did not differ from controls in the parameters tested. In the operated dogs, histology from cartilage samples showed initial osteoarthrotic changes in the patellar surface and the medial condyle of the femur. Histologic changes were greatest in the patellar surface of the femur, as assessed by the Mankin scores. At the very onset of osteoarthrosis, subchondral bone remodeling increases, but the bone structural changes are indistinct. It seems that in this osteoarthrosis model, cartilage lesions precede major subchondral changes in the structure of the bone.