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Farmed cervids are of growing economic importance in the midwestern United States. Although diseases of wild and captive cervids have been examined in more northerly climates, little information exists on the health challenges of deer in the Midwest. We characterized and summarized the causes of mortality in farmed white-tailed deer (Odocoileus virginianus) submitted to the University of Missouri Veterinary Medical Diagnostic Laboratory (Columbia, MO, USA) over a 19-y period (2004–2023). Of 388 cases examined, 253 (65%) were carcasses submitted for autopsy, and 135 (35%) cases were tissue samples harvested by field veterinarians. Infectious disease was the most common cause of mortality (n = 335; 86.3%). Of infectious causes, primary pneumonia was most common (n = 140; 41.7%), followed by septicemia (n = 68; 20.1%), and primary enteritis (n = 64; 19.1%). Viruses were detected in 18% of pneumonia cases. The most common non-infectious diagnoses were emaciation and trauma (both 4 each; 1%). Thirteen animals (3.4%) died of unknown causes. Forty-nine percent of cases were juvenile deer <1-y-old. Most cases were received in the summer (212; 54.6%). Infectious diseases, particularly bacteria and viruses, pose a significant health challenge to farmed deer in the midwestern United States. [ABSTRACT FROM AUTHOR]

Background/objectiveWhole organ in vitro intervertebral disc models have been associated with poor maintenance of cell viability. No previous studies have used a rotating wall vessel bioreactor for intervertebral disc explants culture. The purpose of this study was to develop and validate an in vitro model for the assessment of biological and biomechanical measures of intervertebral disc health and disease.MethodsTo this end, endplate-intervertebral disc-endplate whole organ explants were harvested from the tails of rats. For the injured group, the annulus fibrosus was penetrated with a 20G needle to the nucleus pulposus and aspirated. Explants were cultured in a rotating wall vessel bioreactor for 14 days.ResultsCell viability and histologic assessments were performed at Day 0, Day 1, Day 7, and Day 14. Compressive mechanical properties of the intervertebral disc were assessed at Day 0 and Day 14. In the annulus fibrosus and nucleus pulposus cells, the uninjured group maintained high viability through 14 days of culture, whereas cell viability in annulus fibrosus and nucleus pulposus of the injured intervertebral discs was markedly lower at Day 7 and Day 14. Histologically, the uninjured intervertebral discs maintained cell viability and tissue morphology and architecture through 14 days, whereas the injured intervertebral discs showed areas of cell death, loss of extracellular matrix integrity, and architecture by Day 14. Stiffness values for uninjured intervertebral discs were similar at Day 0 and Day 14, whereas the stiffness for the injured intervertebral discs was approximately 2.5 times greater at Day 14.ConclusionThese results suggest that whole organ intervertebral discs explants can be successfully cultured in a rotating wall vessel bioreactor to maintain cell viability and tissue architecture in both annulus fibrosus and nucleus pulposus for at least 14 days. In addition, the injury used produced pathologic changes consistent with those seen in degenerative intervertebral disc disease in humans. This model will permit further study into potential future treatments and other mechanisms of addressing intervertebral disc disease.

Background: Large meniscal defects are a common problem for which current treatment options are limited. Hypothesis: Treatment of posterior medial meniscal defects in dogs with small intestinal submucosa is superior to partial meniscectomy in terms of clinical limb function, chondroprotection, and amount and type of new tissue in the defect. Study Design: Controlled laboratory study. Methods: A total of 51 mongrel dogs underwent medial arthrotomy with creation of standardized meniscal defects. The dogs were divided into groups based on defect treatment: small intestinal submucosa meniscal implant (n = 29) or meniscectomy (n = 22). The dogs were assessed for lameness by subjective scoring after surgery and sacrificed at 3, 6, or 12 months and assessed for articular cartilage damage, gross and histologic appearance of the operated meniscus, amount of new tissue in the defect, equilibrium compressive modulus of meniscal tissue, and relative compressive stiffness of articular cartilage. Results: Dogs in the meniscectomy groups were significantly (P < .001) more lame than dogs treated with small intestinal submucosa. Joints treated with small intestinal submucosa had significantly (P < .001) less articular cartilage damage, based on india ink staining, than did those treated with meniscectomy. Menisci receiving small intestinal submucosa had more tissue filling in the defects than did menisci receiving no implants, and this new tissue was more mature and meniscus-like and better integrated with remaining meniscus. Conclusion: Small intestinal submucosa scaffolds placed in large meniscal defects resulted in production of meniscus-like replacement tissue, which was consistently superior to meniscectomy in amount, type, and integration of new tissue; chondroprotection; and limb function in the long term. Clinical Relevance: Small intestinal submucosa implants might be useful for treatment of large posterior vascular meniscal defects in humans. Keywords: meniscus; small intestinal submucosa; meniscectomy; tissue engineering; dog, The meniscal-deficient knee is a common problem facing orthopaedic surgeons. Approximately 1 million meniscal surgeries are performed each year in the United States alone. (24) Although repair of meniscal lesions [...]

Surgical repair of the anterior cruciate ligament (ACL) can involve autograft or allograft materials. Allografts are typically chosen to avoid donor site morbidity associated with autografts harvest, but they can also result in a prolonged inflammatory period and delayed graft remodeling when compared to autografts. The aim of this study was to investigate the use of gold nanoparticles (AuNPs) conjugated to allografts to determine if AuNPs can reduce inflammation and enhance graft remodeling in an ovine model. Six sheep had their ACL surgically removed and replaced with a decellularized human gracilis tendon. Three of the sheep received grafts conjugated with 20 nm gold nanoparticles, while three of the sheep received grafts without the gold nanoparticles. The sheep were sacrificed 8 weeks after ACL reconstruction. Immediately following sacrifice, joint fluid was collected for cytology. Semi-quantitative histological scoring of the bone tunnel portion and the intra-articular portion of the grafts were performed independently along with descriptive analysis of histologic changes and quantitative analysis of revascularization. The results demonstrated that AuNP experimental grafts had an overall better histological scores than the non-AuNPs graft. The AuNPs grafts exhibited decreased inflammation in the bone tunnel portion of the graft, the intra-articular portion of the graft, and in the synovial fluid cell count. Overall, the results demonstrated that the grafts conjugated with nanoparticles have the potential to be influence inflammation and overall remodeling response. [ABSTRACT FROM AUTHOR]