Contrast radiography performed at the same time as intrathecal analgesia provides useful information regarding the presence of MF tears and DDFT tears, which can assist in the decision of whether to manage the lameness conservatively or with tenoscopic evaluation.

This study aimed to investigate immediate cell survival and distribution following different administration routes of mesenchymal stem cells (MSCs) into naturally occurring tendon injuries. Ten million MSCs, labeled with technetium-99m hexamethylpropyleneamine oxime, were implanted into 13 horses with naturally occurring tendon or ligament injuries intra-lesionally, intravenously and by regional perfusion, and traced for up to 48 h using planar gamma scintigraphy. Labeling efficiencies varied between 1.8% and 18.5% (mean 9.3%). Cells were retained in the damaged area after intra-lesional administration but only 24% of cells were still present within the tendon after 24 h. After intravenous injection, cells largely distributed to the lung fields, with no detectable cells in the tendon lesions. Significant labeling of the tendon lesions was observed in 11/12 horses following regional perfusion but at a lower level to intra-lesional injection. The highest cell numbers were retained after intra-lesional injection, although with considerable cell loss, while regional perfusion may be a viable alternative for MSC delivery. Cells did not "home" to damaged tendon in large numbers after intravenous administration. Cells were detected in the lungs most frequently after intravascular administration, although with no adverse effects. Low cell retention has important implications for designing effective clinical therapies for human clinical use. #

Sphenopalatine sinus disease should be considered a rare cause of the clinical signs described. Knowledge of the anatomical variation of the sphenopalatine sinus is vital for interpreting CT images. A combination of CT and sinoscopy provides the most comprehensive approach for diagnosis and treatment of sphenopalatine sinus disease.

Several pelvic parameters are suitable for objective quantification of changes after diagnostic analgesia in hindlimb-lame horses. A change of 9-13% per lameness grade can be expected. Upward movement of the tubera coxae is the most sensitive objective measure for quantifying a response to diagnostic analgesia. However, when assessed visually, this measure requires simultaneous focusing on pelvic and limb movements. Other parameters that show a similar response might be more easily perceived, requiring only assessment of tubera coxae range of motion or downward displacement of the sacrum without simultaneous focus on limb movement.

Summary Background Pathology of the digital flexor tendon sheath is a significant cause of lameness in the horse. Imaging is important to identify lesions and inform on prognosis prior to tenoscopic surgery. Objectives To use a large population to evaluate 1) the sensitivity and specificity of digital flexor tendon sheath (DFTS) contrast radiographs in diagnosing manica flexoria (MF) tears, deep digital flexor tendon (DDFT) tears and constriction of the palmar/plantar annular ligament (PAL) using novel criteria; 2) predisposition to pathology in signalment and limb affected. Study design Multicentre retrospective cohort study. Methods The medical records of 206 horses with lameness localised to the DFTS, contrast radiographs and subsequent tenoscopic surgery were reviewed. Breed and limb predispositions were evaluated for pathology of the DDFT, MF and PAL constriction. Contrast radiographs of the DFTS were reviewed by four masked operators and for each pathology the sensitivity, specificity and interobserver variability were calculated. Results Contrast tenography was a sensitive test for MF tears (92% confidence interval [CI] 88.4–94.4%; specificity 56%, CI 51.1–61.1%) and specific for diagnosing DDFT tears (73%, CI 68.6–76.8%; sensitivity 54%, CI 47.8–60.2%) but had a lower sensitivity (71%, CI 65.1–75.9% ) and specificity (45%, CI 39.1–52.0%) for PAL constriction. It had good to substantial interobserver agreement for MF and DDFT tears (Krippendorff's alpha 0.68 and 0.46 respectively). Ponies (57%) and cobs (58%) were significantly more likely to be affected with MF tears (other breeds 20–39%, P = 0.003) and Thoroughbreds (50%), warmbloods (45%) and draught breeds (48%) were more likely to have DDFT tears (other breeds 22–34%, P = 0.01). MF tears and PAL constriction were overrepresented in the hindlimbs compared to DDFT tears in forelimbs. Main limitations No standardisation of contrast radiographs was possible. The subjectivity of diagnosis of PAL constriction may also have led to bias. Radiographs were read as JPEGS reducing ability to manipulate images. Conclusions Contrast radiography of the DFTS is accurate in the pre‐operative diagnosis of DFTS pathologies. Different pathologies are overrepresented in certain breeds and limbs.

Gait analysis in horses has moved from the laboratory into the outside world enabling researchers and clinicians to make use of quantitative measurements to provide evidence aiding clinical decision making. In this article we explain how the two major visual signs of lameness -head nod and hip hikeare linked to the mechanics of lameness. These parameters should be regarded as well suited for incorporation into clinical decision making being easily measurable e.g. with inertial sensors under nonlaboratory conditions and representative of the underlying mechanical changes. A brief overview of the results of validation studies of the use of inertial sensors for quantification of movement symmetry shows that accuracy, precision and repeatability with current sensor generations are in the order of 3-7 mm; this is below the reported detection threshold for movement symmetries 'by eye'. Recent studies with inertial sensors have investigated conditions relevant to the clinical lameness examination: lungeing, flexion tests and diagnostic analgesia. Lungeing introduces kinematic adaptations rendering head and pelvic movement asymmetrical, even in sound horses. First guideline values are available for changes after flexion tests and diagnostic analgesia, and we understand which parameters show consistent changes. This is crucial for investigating the effects in horses with different orthopaedic deficits. In conclusion, the current inertial sensor systems, while not quantifying all the gait adaptations seen in lame horses, characterise the major mechanical changes affecting fore-and hindlimb lame horses. In order to avoid misinterpretation of the generated data, users should have a thorough understanding of the gait parameters and be aware of sensor limitations in terms of accuracy, precision and repeatability.

Odontogenic tumors present as locally invasive, slow growing, firm swellings on the face. They are rare in all species and are characterized histologically by the degree of differentiation and dental tissue of origin. Radiographic appearance is not pathognomonic for these lesions. Computed tomographic (CT) examination allows exact determination of tumor extension and aggressiveness.The objectives of this retrospective, case series study were to describe the clinical presentation, CT characteristics, and outcome in horses with histologically confirmed odontogenic tumors, and to identify imaging features suggestive of individual types of tumors. Four ameloblastomas, two ameloblastic carcinomas, three ameloblastic fibromas, and two complex odontomas were included. All but one complex odontoma presented as a single mass. All tumors were associated with maxillary or mandibular bone expansion, alveolar and cortical bone lysis, and cortical bone thinning. The majority also had cortical bone thickening and periosteal proliferation. All tumors contained some degree of mineral attenuation, although only the complex odontomas contained enamel attenuation allowing differentiation from other types of odontogenic tumors in this study.Ameloblastomas were found to have variable CT characteristics likely due to the sub-groups of ameloblastomas. Both ameloblastic carcinomas contained a mixture of mineralized and soft tissue attenuating material whereas ameloblastic fibromas were mainly composed of soft tissue attenuating material. Computed tomographic characteristics of odontogenic tumors generally indicate that they are expansile, aggressive tumors and can occur in a wide range of ages. Further investigation is needed to elucidate differences between each type of equine odontogenic tumor.

Summary Primary fungal sinusitis was identified in 5 horses displaying signs of headshaking. All 5 horses had fungal plaques adhered to the infraorbital canal (IOC). Headshaking signs were exhibited by 3 horses prior to treatment and 2 horses after treatment. Standing computed tomography (CT) identified erosion of the IOC in the 2 cases in which it was performed. Fungal culture and PCR identified 3 species of fungi, Rhizomucor pusillus, Scedosporium apiospermum and Aspergillus nidulans which have not previously been described as a cause of sinusitis in horses. Surgical debridement followed by topical antifungal therapy was used in all 5 horses. Recurrence of the fungal plaques in 4 horses necessitated further treatment. The headshaking signs and nasal discharge resolved in 3 horses allowing a return to their previous use. Two horses developed persistent headshaking signs despite multiple treatments. Primary fungal sinusitis should be considered as a cause of headshaking signs in horses, due to a suspected trigeminal neuropathy. Computed tomography is valuable in identifying erosion of the IOC which is not identified with conventional radiography. Three out of the 5 cases were treated successfully but permanent resolution of the fungal infection is difficult to achieve once the bone overlying the infraorbital nerve has been eroded.