Einleitung Fibro-ossäre Neoplasien stellen benigne Tumoren dar, die aus variablen Anteilen von Binde- und Knochengewebe bestehen. Hierbei muss zwischen Osteomen, ossifizierenden Fibromen und fibrösen Dysplasien unterschieden werden.

SummaryA 7‐year‐old plains zebra(Equus quagga)mare was presented to the Clinic for Horses, University of Veterinary Medicine Hannover, Foundation, Germany as an emergency. The owner reported that the mare was unable to stand after a suspected traumatic episode at the home yard. The mare was transported in lateral recumbency in a trailer. Clinical examination revealed tachycardia (up to 102 beats/min), tachypnoea (28 breaths/min), mild fever (38.7°C) and clinical dehydration with elastic skin and dry and red mucous membranes. Neurological examination showed paraplegia with complete loss of nociception of the mid‐thoracic region and caudal to it. In contrast, examination of the thoracic limbs revealed marked extensor rigidity and hyperaesthesia resulting in an enhanced acute response to minimal touch of the neck and shoulder region. Lateral radiographs of the thoracic vertebral column led to the diagnosis of a complete fracture of the vertebral body of the 7th thoracic (T) vertebra with suspected traumatic compression of the spinal cord. Post‐mortem examination confirmed the diagnosis. Gross pathology revealed a complete comminuted fracture of T7 with marked compression of the spinal cord. This is the first report describing the clinical, radiological and pathological findings of a fracture of a thoracic vertebra leading to aSchiff‐Sherrington syndromein a zebra(Equus quagga).

Objective: Coughing and dysphagia have been described following prosthetic laryngoplasty (LP) with or without ventriculectomy/ventriculocordectomy (VENCE) for the treatment of recurrent laryngeal neuropathy. All previous case descriptions include patients with acute onset of clinical signs after surgery that persisted. The authors observed a late-onset of dysphagia and coughing months to years after LP VENCE. The condition was always associated with an abnormality of the aryepiglottic fold (AEF). Treatment options for those patients are limited. We suggest augmentation of the AEF as treatment for affected horses. The goal of the study was two-fold: Firstly, to describe a new condition of late-onset dysphagia in horses following LP VENCE associated with an abnormal appearance of the AEF, and secondly, to offer a minimally invasive and successful treatment for those patients. Material and methods: Six horses were presented because of dysphagia and coughing with an onset of months to years after LP VENCE. Endoscopically, the AEF always appeared thinner and more flaccid to a varying degree. The food path was traceable along the AEF into the trachea using dyed molasses. An initial injection of hyaluronic acid (HA) into the AEF led to immediate improvement of the dysphagia. The procedure was performed in the standing sedated horse. The needle was placed through the cricothyroid ligament and the injection performed under endoscopic guidance. Results: All horses tolerated the injection well. Injection of HA was successful only in the short term in all cases and repeated injections were needed for permanent resolution using either cross-linked HA, polyacrylamide hydrogel or platelet rich plasma. Conclusion and clinical relevance: Horses may develop dysphagia and coughing months to years after LP VENCE as a late-onset complication. The condition seems to be associated with an abnormal appearance and function of the AEF. Successful treatment is possible by augmenting the AEF. However, careful patient selection is mandatory.

Complications associated with intravenous catheters have been reported frequently and are not only limited to thrombophlebitis of the respective vessel. There are some reports of air embolism in small and large animals described in the literature. The source of air aspiration can be traumatic, iatrogenic during surgeries and also related to venous catheters. Not only the reason for air aspiration, but also the consequences differ between human, small animals and horses. This present article describes the clinical signs, treatment and short-term outcome of two horses with suspected venous air embolism but with different underlying diseases. Both horses exhibited a sudden onset of cardiovascular shock and periods of neurological disorder during their hospitalization. One horse also showed colic symptoms. In both horses an inadvertently opened venous catheter was found at the onset of unexpected symptoms. Therefore, air embolism due to air aspiration by the open venous access might be possible. In air embolism, a decreased perfusion and reduced oxygen delivery are potential sequelae. An impairment of the cardiovascular system with subsequent cerebellar hypoperfusion and embolism might be an explanation for the observed clinical signs. These were tachycardia, delayed capillary refill time and excitement. Furthermore, ataxia, seizures and blindness was observed. Intensity and duration of clinical signs differed between both horses. Following supportive treatment, both horses were discharged from hospital in a good condition. The exact amount of air leading to clinical signs is not exactly known despite different studies aiming at finding a lethal dose. However, rate and amount of air aspiration, as well as body weight and health status of the patient may also have an effect on occurrence of overt clinical signs of venous air embolism. Due to the lack of specific treatment options, symptomatic therapy has been performed. This includes intravenous fluid administration for cardiovascular stabilization and anti-inflammatory treatment. Additionally, nasal oxygen insufflations may increase tissue oxygenation. Furthermore, neuroprotectiv treatment, like dexamethason, might also be advantageous regarding the pathophysiology of venous and cerebellar air embolism. Antithrombotic treatment can be initiated in order to avoid formation of thrombus following capillary perfusion disturbances in the circulation. Diagnostic proof is lacking in both cases, however, presence of an open venous catheter and the observed clinical signs lead to the suspected diagnosis of venous air embolism. Venous air embolism seems to have a low incidence in equine medicine, and the exact dimension of clinical signs may not always be obvious. Close attention should be paid at infusion lines, air within syringes, disconnection of catheters and their extensions and catheter caps. Problems may occur due to manipulations by the horse itself or due to improper handling by the attending veterinarian. Several medical devices aim at reducing the risk of air aspiration into the venous circulation during handling. These are for example separate clips, infusion filters and needleless connectors with valves. A close monitoring of the correct placement and appropriate use of intravenous fluids and infusion hardware is mandatory. The aim of this article is to increase the awareness for venous air embolism in veterinary medicine as a possible complication of intravenous catheters.

OBJECTIVE:The aim of the present study was to verify the diagnostic validity of low-field magnetic-resonance-imaging (MRI) findings in septic diseases of the foot region following penetrating sole injuries caused by nails.MATERIALS AND METHODS:MRI examinations were performed in 10 horses with injuries in the foot region. The diagnostic findings were validated by conventional methods (clinical, surgical, radiological, sonographic, and computed tomographic findings and/or post-mortem histological examination).RESULTS:Navicular bone involvement was revealed most accurately, with a high degree of predictability, and was best detected by fat-suppressed T2 or short-TI inversion recovery (STIR) sequences. MRI examinations of defects in the deep digital flexor tendon showed a high level of sensitivity, but these findings were less specific than changes to the navicular bone. They could be best reproduced in transverse T2-weighted fast spin echo sequences (T2w FSE). The penetration tract was recognisable in all cases and in all planes, and the T2w FSE proved to be very suitable for diagnosis. Septic bursitis was revealed least accurately by MRI. Bursal disease was best recognised in the sagittal plane.CONCLUSION AND CLINICAL RELEVANCE:MRI is a reliable method for confirming the diagnosis of diseases in the foot region after injuries caused by foreign bodies, particularly nails. A transverse T2w FSE is best suited for demonstrating a penetration tract and tendon damage. Visualisation of the penetration tract and secondary reactions of the navicular bone are crucial for diagnosing bursitis. Fat-suppressed sequences can clearly show bone involvement when the penetration tract has not reached the bone. The cases described illustrate that MRI is an appropriate method for evaluating puncture wounds in the foot region. Only MRI allows for intravital assessment of various structures within the hoof capsule. This information is essential for deciding upon targeted therapy while avoiding unnecessary therapies.

Background. Mesenchymal stromal cells (MSCs) are increasingly used for clinical applications in equine patients. For MSC isolation and expansion, a laboratory step is mandatory, after which the cells are sent back to the attending veterinarian. Preserving the biological properties of MSCs during this transport is paramount. The goal of the study was to compare transport-related parameters (transport container, media, temperature, time, cell concentration) that potentially influence characteristics of culture expanded equine MSCs. Methods. The study was arranged in three parts comparing (I) five different transport containers (cryotube, two types of plastic syringes, glass syringe, CellSeal), (II) seven different transport media, four temperatures (4 °C vs. room temperature; −20 °C vs. −80 °C), four time frames (24 h vs. 48 h; 48 h vs. 72 h), and (III) three MSC concentrations (5 × 106, 10 × 106, 20 × 106 MSC/ml). Cell viability (Trypan Blue exclusion; percent and total number viable cell), proliferation and trilineage differentiation capacity were assessed for each test condition. Further, the recovered volume of the suspension was determined in part I. Each condition was evaluated using samples of six horses (n = 6) and differentiation protocols were performed in duplicates. Results. In part I of the study, no significant differences in any of the parameters were found when comparing transport containers at room temperature. The glass syringe was selected for all subsequent evaluations (highest recoverable volume of cell suspension and cell viability). In part II, media, temperatures, or time frames had also no significant influence on cell viability, likely due to the large number of comparisons and small sample size. Highest cell viability was observed using autologous bone marrow supernatant as transport medium, and “transport” at 4 °C for 24 h (70.6% vs. control group 75.3%); this was not significant. Contrary, viability was unacceptably low (<40%) for all freezing protocols at −20 °C or −80 °C, particularly with bone marrow supernatant or plasma and DMSO. In part III, various cell concentrations also had no significant influence on any of the evaluated parameters. Chondrogenic differentiation showed a trend towards being decreased for all transport conditions, compared to control cells. Discussion. In this study, transport conditions were not found to impact viability, proliferation or ability for trilineage differentiation of MSCs, most likely due to the small sample size and large number of comparisons. The unusual low viability after all freezing protocols is in contrast to previous equine studies. Potential causes are differences in the freezing, but also in thawing method. Also, the selected container (glass syringe) may have impacted viability. Future research may be warranted into the possibly negative effect of transport on chondrogenic differentiation.

In this study, superparamagnetic iron oxide (SPIO) particle-labeled mesenchymal stromal cells (MSCs) were injected intra-articularly into osteoarthritic knee joints. Their fate and distribution were evaluated using magnetic resonance imaging (MRI) and macroscopic and histologic postmortem examination. Osteoarthritis was induced in 12 sheep by bilateral meniscectomy. After 6 weeks, one knee joint received 10 × 106 SPIO-labeled MSCs (Molday Ion Rhodamine B). Contralateral knees received a control injection of a) PBS, b) SPIO in PBS, c) 10 × 106 nonvital SPIO-labeled MSCs in PBS, or d) no injection. MR images were acquired immediately after injection and 1, 4, 8, and 12 weeks thereafter using a 0.5-T unit and a T2* sequence. Signal intensity of synovial fluid and synovial lining was assessed semiquantitatively using a scoring system. Viable SPIO-labeled MSCs produced a strong hypointense signal in the synovial fluid immediately after injection, but normal signal intensity of the synovial fluid was observed 1 week later. Synovial lining maintained its hypointensity throughout the study period. Nonvital SPIO-labeled MSCs induced hypointense signals of the synovial fluid; synovial lining appeared weak and inconsistently hypointense in the following weeks. Pure SPIO produced a strong hyperintense signal in the synovial fluid at the time of injection only. Histologically, in all knee joints receiving viable SPIO-labeled MSCs, SPIO particles were detected (Prussian blue) within the synovial lining, dorsal fat pad, and neomeniscus tissue, but not in osteochondral samples. Few SPIO particles were detected in joints injected with nonvital SPIO-labeled MSCs. Immunohistologically, no increased cell death (TUNEL) was observed in the area of detected SPIO particles, but we did observe potential chondrogenic cell differentiation (Safranin O or S100β). We conclude that viable SPIO-labeled MSCs remain detectable within the joint for 12 weeks and attach themselves to some but not all diseased joint structures.

In this study, the therapeutic effect of intra-articularly injected autologous mesenchymal stromal cells (MSCs) was evaluated in an ovine osteoarthritis (OA) model using consecutive magnetic resonance imaging (MRI), radiography, and macroscopic and histologic postmortem examination. In 12 sheep, OA was induced by bilateral, lateral meniscectomy. After 6 weeks, 20 × 10 6 bone marrow-derived MSCs (50% MSCs were superparamagnetic iron oxide particle labeled) were injected intra-articularly into one knee joint. The contralateral knee served as negative control. MR images were acquired before OA induction, immediately before and after MSC injection, and 1, 4, 8, and 12 weeks thereafter using a 0.5T unit and a T2* gradient echo sequence. Radiographs were obtained before OA induction, at MSC injection, and 12 weeks thereafter. The MRI scoring system included articular cartilage, bone, joint capsule, and synovial fluid evaluation. The radiographic scoring system included the joint space and bone. Postmortem evaluation entailed macroscopic and histologic assessment. Longitudinal MRI revealed a significant deceleration of OA progression in MSC-treated joints. However, at the conclusion of the study, there was no significant difference in the degree of OA detected by MRI, radiography, and postmortem evaluation between the treatment and control group. The degree of OA on MRI varied among the 12 animals at the time of injection, but there was no difference between the left and right limb. In conclusion, intra-articular MSCs decreased OA progression. However, no significant treatment effects were seen at the conclusion of the study at 12 weeks. This somewhat contradicts previously published results. Nevertheless, the choice of OA model, outcome measures, or lack of additional medication might explain the differences. Our results indicate that OA might benefit from intra-articular MSC injection, but further studies are needed to refine patient selection and injection parameters for a more substantially improved outcome.

Stem cells in the form of mesenchymal stromal cells derived from various sources have been identified to have the potential of supporting the therapy of joint disease in the horse, and preliminary data has been published about the clinical application of stem cells in horses suffering from clinical joint disease. Furthermore, the horse is recognized to be the ideal large animal model for the preclinical study of cell therapy in joints. The advantage of this species in this respect is the size of the joints, which makes surgical applications practically feasible in analogy to human surgery. Additionally, the horse is the only model species with a cartilage thickness in the knee joint comparable to that of humans. Especially the fact that horses develop clinical joint disease discerns this species from other large animal models like small ruminants. The therapy of clinical disease in model animal species represents the ideal situation for preclinical studies of novel therapeutic strategies. Here, we describe the experimental and clinical approaches to joint disease in the horse.

The purpose of this study was to evaluate the use of three different superparamagnetic iron oxide (SPIO) particles for labeling of ovine and equine bone marrow (BM)-derived multipotent stromal cells (MSCs) in vitro. MSCs were obtained from five adult sheep and horses, respectively. After three passages (p3), cells were labeled with either 1) Molday ION Rhodamine B, 2) Endorem, 3) Resovist, or 4) remained unlabeled as control. Labeling efficiency, marker retention, and long-term detectability in MRI until p7 were evaluated. Further, proliferation capacity and trilineage differentiation as indicators for potential impact on stromal cell characteristics were assessed. MSCs of both species were successfully labeled with all three SPIO products. A high, exclusively intracellular, iron uptake was achieved by Molday ION Rhodamine B only. Labeling with Resovist led to prominent extracellular iron presence; labeling with Endorem was less efficient. During MRI, all labeled cells showed strong hypointense signals, contrary to unlabeled controls. Resovist induced the largest areas of hypointense signals, followed by Molday ION Rhodamine B and Endorem. MRI signal detectability decreased from p4 to p7. Proliferation, adipogenic, and osteogenic differentiation potential were not reduced by cell labeling compared to unlabeled cells. Chondrogenic differentiation capacity decreased with increasing amount of iron associated with the cells. Among the three products, Resovist and Molday were identified as promising labeling agents. While Resovist achieved superior results in most of the assessed parameters, Molday ION Rhodamine B ensured intracellular iron uptake without extracellular SPIO complexes and consistent hypointense signals on MRI.

A retrospective analysis of 619 upper and lower cheek teeth from 62 horses was performed. Based on clinical findings, as well as radiographic and magnetic resonance (MR) imaging findings, the teeth were classified into five groups. There were 20 teeth with abnormal MR imaging signals as well as clinical alterations and 599 healthy teeth. Using MR imaging, the appearance of pulp in diseased and disease-free teeth was compared, and the appearance of abnormal pulp was studied. Subsequently, the ability of MR imaging to diagnose pulpitis and pulp necrosis in teeth with normal external appearance was investigated. In horses with clinically verified dental disease, abnormal MR imaging findings were confirmed in the pulp of all affected teeth. An enlarged blurred pulp image with a lower signal intensity was observed only in clinically diseased teeth and was a reliable criterion for diagnosing dental disease on MR imaging. On the other hand, partial or complete absence of pulp in all MR imaging sequences was observed in both diseased and nondiseased teeth. These data demonstrate that pulp changes in equine cheek teeth can be evaluated using MR imaging.

In this study, a newly-developed model for training veterinary students to inject the jugular vein in horses was evaluated as an additional tool to supplement the current method of teaching. The model was first validated by 19 experienced equine veterinarians, who judged the model to be a realistic and valuable tool for learning the technique. Subsequently, it was assessed using 24 students who were divided randomly into two groups. The injection technique was taught conventionally in a classroom lecture and a live demonstration to both groups, but only group 1 received additional training on the new model. All participants filled out self-assessment questionnaires before and after group 1 received training on the model. Finally, the proficiency of both groups was assessed using an objective structured clinical evaluation (OSCE) on live horses. Students from group 1 showed significantly improved confidence after their additional training on the model and also showed greater confidence when compared to group 2 students. In the OSCE, group 1 had a significantly better score compared to group 2: the median (with inter-quartile range) was 15 (0.7) vs. 11.5 (2.8) points out of 15, respectively. The training model proved to be a useful tool to teach veterinary students how to perform jugular vein injections in horses in a controlled environment, without time limitations or animal welfare concerns. The newly developed training model offers an inexpensive, efficient, animal-sparing way to teach this clinical skill to veterinary students.

The tarsal sheath is a relatively large structure and has an exposed position on the medial aspect of the hock in horses. Because of that, it may be affected by various diseases. The precise knowledge of anatomical location, extend and relationship to surrounding structures and diagnostic modalities is an important prerequisite to diagnose those conditions. The goal of the present study was to illustrate and document the anatomical details in cadaver limbs. Furthermore, a retrospective analysis of all cases with tarsal sheath involvement presented to the Large Animal Clinic for Surgery, Faculty of Veterinary Medicine, University of Leipzig in a seven year period (2005-2011) was performed. A detailed anatomical description of the tarsal sheath based on our own evaluation as well as literature findings is presented. It was noted that the description of the anatomical situation in the present literature is neither consistent, nor precise and partly outdated. Among patients presented to our hospital, diseases of the tarsal sheath have a low incidence (0.3 %). Based on the clinical findings, most cases could be allocated to one of four groups: 1) acute to chronic, subclinical aseptic tenosynovitis, 2) chronic, clinical apparent, aseptic tenosynovitis, 3) acute, septic tenosynovitis due to laceration, and 4) acute tenosynovitis secondary due to cellulitis. Some conditions warrant immediate and comprehensive treatment whereas other conditions have a low clinical relevance and may heal on their own. Prognoses for life, for full athletic function as well as cosmetic appearance of the hock vary considerably among the diseases affecting the tarsal sheath.

The objective of this study was to compare bone marrow (BM) aspirates from the sternum and the tuber coxae of middle-aged horses. Bone marrow was obtained from the sternum and both tubera coxae of 12 healthy, 13-year-old geldings. Two different puncture techniques were used for the tuber coxae. The 2 syringes used for sternal sampling were evaluated separately. The mononuclear cell (MNC) fraction of the BM was isolated and the mesenchymal stem cells (MSCs) were culture-expanded. At the sternum, BM aspiration was always possible. Bone marrow aspiration at the tuber coxae required straight and deep needle penetration combined with high negative pressure. With this technique a median sample amount of 11.0 mL with large individual variation was obtained. A median of 3.06 × 10(6) MNC/mL BM (1st syringe) and 2.46 × 10(6) MNC/mL BM (2nd syringe) was isolated from sternal samples. In contrast, the tuber coxae yielded a median of 0.27 × 10(6) MNC/mL BM. The first passage yielded a median of 2.19 × 10(6) MSC (1st syringe) and 1.13 × 10(6) MSC (2nd syringe) from sternal samples, compared to a significantly lower median number of MSC from tuber coxae BM (0.06 × 10(6) MSC). The number of MNC and MSC obtainable from the BM aspirates taken from the tuber coxae is significantly lower than that obtained from the sternal BM aspirates. Autologous BM for the equine athlete is particularly clinically relevant at an advanced age. Based on our findings, the tuber coxae cannot be recommended for BM aspiration in middle-aged horses.

Article Simulation system for puncture of the Vena jugularis sinistra in horses was published on September 6, 2012 in the journal Biomedical Engineering / Biomedizinische Technik (volume 57, issue SI-1-Track-O).

Regenerative medicine is one of the most intensively researched medical branches, with enormous progress every year. When it comes to translating research from bench to bedside, many of the pioneering innovations are achieved by cooperating teams of human and veterinary medical scientists. The veterinary profession has an important role to play in this new and evolving technology, holding a great scientific potential, because animals serve widely as models for human medicine and results obtained from animals may serve as preclinical results for human medicine. Regenerative veterinary medicine utilizing mesenchymal stromal cells (MSC) for the treatment of acute injuries as well as chronic disorders is gradually turning into clinical routine. As orthopaedic disorders represent a major part of all cases in veterinary clinical practice, it is not surprising that they are currently taking a leading role in MSC therapies. Therefore, the purpose of this paper is to give an overview on past and current achievements as well as future perspectives in stem cell-based tissue engineering in veterinary orthopaedics.

Stem cells have been used for the treatment of equine tendon injuries with excellent success for several years. Also for the treatment of joint disease stem cells are regarded as a promising tool. This article focuses on the implementation of stem cell therapy into clinical practice. Besides the scientific background, indications and prospects of success are discussed and practical know-how concerning sample collection and stem cell application is provided.

SummaryIn this article we report the course of disease in a mare following severe vaginal injury during natural cover. Although the genital injury healed completely, the mare developed extensive intra‐abdominal intestinal adhesions causing complete small intestinal obstruction 2 years after the incident. The adhesion was not accessible during initial emergency laparotomy and a standing, hand‐assisted laparoscopic adhesiolysis and jejuno‐jejunal end‐to‐end anastomosis were subsequently performed. The mare was subjected to euthanasia 10 weeks after surgery due to recurrence of abdominal pain. The pertaining literature is discussed in regards to this case.