Surgical excision of primary canine rectal tumors by an anal approach in twenty-three dogs.

Objective: To describe an anal approach for excision of primary rectal tumors in dogs and to report outcome.

Study Design: Retrospective study.

Animals: Dogs (n=23) with primary rectal tumors.

Collagenolytic protease expression in cranial cruciate ligament and stifle synovial fluid in dogs with cranial cruciate ligament rupture.

Objective: To determine expression of collagenolytic genes and collagen degradation in stifle tissues of dogs with ruptured cranial cruciate ligament (CCL).

Animals: Six dogs with CCL rupture and 11 dogs with intact CCL.

Procedures: Gene expression in CCL tissue and synovial fluid cells was studied using reverse transcriptase-polymerase chain reaction (RT-PCR).

Response of the osteocyte syncytium adjacent to and distant from linear microcracks during adaptation to cyclic fatigue loading.

Cyclic loading induces fatigue in bone and initiates a complex, functionally adaptive response. We investigated the effect of a single period of fatigue on the histologic structure and biomechanical properties of bone. The ulnae of 40 rats were subjected to cyclic fatigue (-6000 microepsilon) unilaterally until 40% loss of stiffness developed, followed by 14 days of adaptation.

Degradation of bone structural properties by accumulation and coalescence of microcracks.

Failure of bone adaptation to protect the skeleton from fatigue fracture is common, and site-specific accumulation and coalescence of microcracking in regions of high strain during cyclic loading is considered a key factor that decreases the resistance of whole bones to fracture. We investigated the effect of cyclic fatigue loading on the monotonic structural properties of the rat ulna during accumulation and coalescence of microcracks. Cyclic end-loading of the ulna was performed at 4 Hz ex vivo at an initial peak strain of -6000 muepsilon to 20% loss of stiffness (n = 7) or 40% loss of stiffness (n = 7) bilaterally.

Macroscopic changes in the distal ends of the third metacarpal and metatarsal bones of Thoroughbred racehorses with condylar fractures.

Objective: To determine changes in the distal ends of the third metacarpal and metatarsal bones (MCIII and MTIII) of Thoroughbred racehorses that had sustained a catastrophic condylar fracture during high-speed exercise.

Sample Population: Fractured and contralateral MCIIIs and MTIIIs from 11 Thoroughbred racehorses that sustained a displaced condylar fracture during racing, both MCIIIs from 5 Thoroughbred racehorses euthanatized because of a catastrophic injury other than a condylar fracture, and both MCIIIs from 5 horses of other breeds that had not been professionally trained or raced.

Procedure: Macroscopic observations were made of the distal ends of the bones before and after digestion of the articular cartilage with NaOH.