Kinetics and kinematics of dog walk exercise in agility dogs of different experiences

The injury rate in agility dogs is relatively high compared to the general population. No study to date has considered the biomechanical effects of the dog walk obstacle in agility trials, highlighting a research need. The aim of this study was to assess forelimb joint kinematics and peak ground reaction forces (PVF) over a dog walk agility obstacle and correlate with experience. Dogs were filmed running across a Kennel Club (KC) standard dog walk for kinematics analysis. Two pressure sensors were secured to the (1)  dog walk contact area at exit and (2) ground at the end of the dog walk  (landing area) for kinetics analysis. Forelimb joints angles and  PVF at the contact zone at the walk exit and landing  were analysed. A key finding is that the way a dog will move across the obstacle changes depending on their level of experience, with experienced dogs showing faster obstacle negotiation and increased flexion of the elbow joint compared to inexperienced competitors. Higher speeds over the dog walk also resulted in significantly increased elbow joint flexion. Another important finding is that PVF at landing are higher is dogs  that are faster and also in dogs performing running technique in comparison to  stopped technique,. Overall, dog walk obstacle created more forelimbs joint flexion and similar PVF in comparison with previously studied agility contact obstacles which leads us to conclude that further research is required to ascertain the long term health implications for dogs used in agility trials

Optimising soft tissue in-growth in vivo in additive layer manufactured osseointegrated transcutaneous implants

Osseointegrated transcutaneous implants could provide an alternative and improved means of attaching artificial limbs for amputees, however epithelial down growth, inflammation, and infections are common failure modalities associated with their use. To overcome these problems, a tight seal associated with the epidermal and dermal adhesion to the implant is crucial. This could be achieved with specific biomaterials (that mimic the surrounding tissue), or a tissue–specific design to enhance the proliferation and attachment of dermal fibroblasts and keratinocytes. The intraosseous transcutaneous amputation prosthesis is a new device with a pylon and a flange, which is specifically designed for optimising soft tissue attachment. Previously the flange has been fabricated using traditional machining techniques, however, the advent of additive layer manufacturing (ALM) has enabled 3–dimensional porous flanges with specific pore sizes to be used to optimise soft tissue integration and reduce failure of osseointegrated transcutaneous implants. The study aimed to investigate the effect of ALM–manufactured porous flanges on soft tissue ingrowth and attachment in an in vivo ovine model that replicates an osseointegrated percutaneous implant. At 12 and 24 weeks, epithelial downgrowth, dermal attachment and revascularisation into ALM–manufactured flanges with three different pore sizes were compared with machined controls where the pores were made using conventional drilling. The pore sizes of the ALM flanges were 700, 1000 and 1250 μm. We hypothesised that ALM porous flanges would reduce downgrowth, improve soft tissue integration and revascularisation compared with machined controls. The results supported our hypothesis with significantly greater soft tissue integration and revascularisation in ALM porous flanges compared with machined controls

Erythrocytometry and seric proteinogram of umbilical cord and jugular of foals at birth and respective mothers

Colheram-se amostras de sangue do cordão umbilical (SCU) e do sangue circulante de cinco eqüinos neonatos, imediatamente após o nascimento, e o sangue da própria mãe, utilizando-se um sistema a vácuo. O material foi submetido à contagem global de hemácias e leucócitos e à determinação do volume globular e da concentração de hemoglobina; à contagem diferencial de leucócitos em esfregaços sangüíneos; e ao cálculo dos índices eritrocitométricos. Foram realizadas a dosagem de proteínas séricas totais e a eletroforese das proteínas séricas em gel de agarose. Não houve diferenças significativas entre os parâmetros do SCU e do sangue da jugular dos potros. No SCU dos potros observaram-se valores mais elevados para contagem global de hemácias (9,75x106/µl), dosagem de hemoglobina (14,65g/dl) e concentração de hemoglobina corpuscular média (37,23g/dl); e valores menores para volume corpuscular médio (40,50fl), proteína total (4,37g/dl), a-globulinas (0,65g/dl), b-globulinas (1,10g/dl), g-globulinas (0g/dl) e contagens global (5,40 x 103/µl) e diferencial de leucócitos, exceto contagem de neutrófilos bastonetes e monócitos, quando comparados com os valores obtidos no sangue de suas mães. _________________________________________________________________________________________________________ ABSTRACTUmbilical cord blood (UCB) and systemic blood samples were collected from five equine neonates, immediately after birth. Systemic blood samples from their mothers were also collected at the same time, using a vacuum system. The samples were submitted to the following analyses: red blood cell and total white blood cell counts; determinations of packed cell volume and hemoglobin concentration; differential white cell count in blood smears; and determination of erythrocytometric values. Total serum proteins quantification and serum proteins electrophoresis in agarose gel were done. No significant difference (P<0.05) was noted between averages in neonate jugular blood and equine UCB. Equine UCB showed higher values of red blood cell count (9.75x106/µ), hemoglobin determination (14.65g/dl), and mean corpuscular hemoglobin concentration (37.23g/dl); but lower values of mean corpuscular volume (40.50fl), total protein (4.37g/dl), a-globulin (0.65 g/dl), b-globulin (1.10g/dl), g-globulin (0g/dl), total (5.40x103/µl), and differential leukocytes count, except for band neutrophils and monocytes counts, when compared to the blood of the mares

Physical, biochemical and cytological characteristics of the equine digital flexor tendon sheath synovial fluid

Foram estudadas as características físico-químicas e citológicas do líquido sinovial da bainha tendínea digital de nove eqüinos hígidos. Verificou-se que o líquido é viscoso, amarelo claro, límpido, livre de partículas e que não coagula à temperatura ambiente. Sua concentração média de ácido hialurônico foi 60,20mg/dl, a taxa de glicose, similar à plasmática e sua concentração protéica não ultrapassou 1,74g/dl, com relação média albumina:globulina de 0,94. O número médio de células nucleadas foi de 313 células/µl, com predominância de grandes células mononucleares e linfócitos. Houve correlação significativa (r = - 0,649, P<0,01) entre o aumento da concentração de ácido hialurônico e a diminuição percentual de linfócitos. As mensurações das características pesquisadas no líquido sinovial da bainha tendínea digital de eqüinos são de execução simples e passíveis de implantação na rotina de atendimentos clínico-cirúrgicos. _________________________________________________________________________________________________________ ABSTRACTPhysical, biochemical and cytological characteristics of the digital flexor tendon sheath synovial fluid were studied in nine clinically normal horses. It is a viscous, pale yellow, clear fluid, without flocculent material and does not clot at room temperature. Its hyaluronic acid mean concentration was 60.20mg/dL, glucose levels were similar to the plasmatic levels, and its protein concentration was up to 1.74g/dL, with mean albumin:globulin ratio of 0.94. Nucleated cells mean number was 313 cells/µL, with predominating large mononuclear cells and lymphocytes. There was a significant correlation (r= -0.649, P<0.01) between increasing hyaluronic acid concentration and decreasing lymphocyte counts. Equine digital tendon sheath synovial fluids can be easily evaluated, being feasible in clinical and surgical routine, and the information may be useful to the diagnosis, treatment and prognosis of animals with tendon sheath associated lesions

Comparative study of two techniques of digital palmar neurorrhaphy in horses

Foram comparadas duas técnicas de neurorrafia em seis eqüinos, divididos em três grupos (G), conforme o tempo para a biópsia. Os animais foram submetidos a neurectomia dos nervos digitais palmares (NDP) e aplicaram-se duas suturas epineurais (SE) e suturas com tubos de silicone (STS) em cada animal. Avaliaram-se os animais mensalmente pelo teste de sensibilidade e exame do aparelho locomotor até a realização das biópsias dos NDP. Aos 30 dias pós-cirurgia foi realizada biópsia no GI, aos 60 dias no GII e aos 180 dias no GIII. Macroscopicamente, o NDP encontrou-se envolvido por tecido conjuntivo fibroso. Microscopicamente, constataram-se proliferação axonal em uma amostra do GI e neuromas nas amostras dos GI, GII e GIII. Houve proliferação de tecido conjuntivo em todos os grupos no local de reparação para SE e adentrando no interior do tubo na STS. Visibilizaram-se infiltrado de células inflamatórias, alterações no coto proximal e degeneração no coto distal na SE e na STS. As técnicas não apresentaram resultados satisfatórios quanto ao grau de regeneração do coto proximal até o coto distal. _________________________________________________________________________________________________________ ABSTRACTTwo neurorrhaphy techniques were compared using six horses divided in three groups (G), based on the biopsy time. After neurectomy of the palmar digital nerves (DPN), two epineural sutures (ES) and two sutures with silicone tube (STS) were applied in each animal. All animals were evaluated monthly by sensitivity test and locomotor apparatus examination until collection of the suture sites by biopsy. Biopsy procedure was performed at 30 days post surgery in G1, 60 days in G2 and 180 days in G3. Grossly, the digital palmar nerve was involved by fibrous connective tissue. Microscopically, axonal growth in one sample from G1 and neuroma in samples from G1, G2 and G3 were observed. Proliferation of connective tissue occurred in all groups in repaired areas of ES and penetrated in the interior of STS tubes. Inflammatory cells, alterations of the proximal stump and degeneration of distal stump in ES and in STS were observed. Both techniques showed no satisfactory results regarding the degree of regeneration from proximal to distal stump

Augmentation and repair of tendons using demineralised cortical bone

BACKGROUND: In severe injuries with loss of tendon substance a tendon graft or a synthetic substitute is usually used to restore functional length. This is usually associated with donor site morbidity, host tissue reactions and lack of remodelling of the synthetic substitutes, which may result in suboptimal outcome. A biocompatible graft with mechanical and structural properties that replicate those of normal tendon and ligament has so far not been identified. The use of demineralised bone for tendon reattachment onto bone has been shown to be effective in promoting the regeneration of a normal enthesis. Because of its properties, we proposed that Demineralised Cortical Bone (DCB) could be used in repair of a large tendon defect. METHODS: Allogenic DCB grafts in strip form were prepared from sheep cortical bone by acid decalcification and used to replace the enthesis and distal 1 cm of the ovine patellar tendon adjacent to the tibial tuberosity. In 6 animals the DCB strip was used to bridge the gap between the resected end of the tendon and was attached with bone anchors. Force plate analysis was done for each animal preoperatively and at weeks 3, 9, and 12 post operatively. At week 12, after euthanasia x-rays were taken and range of movements were recorded for hind limbs of each animal. Patella, patellar tendon - DCB and proximal tibia were harvested as a block and pQCT scan was done prior to histological analysis. RESULTS: Over time functional weight bearing significantly increased from 44% at 3 weeks post surgery to 79% at week 12. On retrieval none of the specimens showed any evidence of ossification of the DCB. Histological analysis proved formation of neo-enthesis with presence of fibrocartilage and mineralised fibrocartilage in all the specimens. DCB grafts contained host cells and showed evidence of vascularisation. Remodelling of the collagen leading to ligamentisation of the DCB was proved by the presence of crimp in the DCB graft on polarized microscopy. CONCLUSION: Combined with the appropriate surgical techniques, DCB can be used to achieve early mobilization and regeneration of a tendon defect which may be applicable to the repair of chronic rotator cuff injury in humans