Ovine pulmonary adenocarcinoma (OPA) is an infectious, neoplastic lung disease of sheep that causes significant animal welfare and economic issues throughout the world. Understanding OPA pathogenesis is key to developing tools to control its impact. Central to this need is the availability of model systems that can monitor and track events after Jaagsiekte sheep retrovirus (JSRV) infection. Here, we report the development of an experimentally induced OPA model intended for this purpose. Using three different viral dose groups (low, intermediate and high), localised OPA tumour development was induced by bronchoscopic JSRV instillation into the segmental bronchus of the right cardiac lung lobe. Pre-clinical OPA diagnosis and tumour progression were monitored by monthly computed tomography (CT) imaging and trans-thoracic ultrasound scanning. Post mortem examination and immunohistochemistry confirmed OPA development in 89% of the JSRV-instilled animals. All three viral doses produced a range of OPA lesion types, including microscopic disease and gross tumours; however, larger lesions were more frequently identified in the low and intermediate viral groups. Overall, 31% of JSRV-infected sheep developed localised advanced lesions. Of the sheep that developed localised advanced lesions, tumour volume doubling times (calculated using thoracic CT 3D reconstructions) were 14.8 ± 2.1 days. The ability of ultrasound to track tumour development was compared against CT; the results indicated a strong significant association between paired CT and ultrasound measurements at each time point (R² = 0.799, p < 0.0001). We believe that the range of OPA lesion types induced by this model replicates aspects of naturally occurring disease and will improve OPA research by providing novel insights into JSRV infectivity and OPA disease progression.

Middle ear disease occurs frequently in dogs. CT has proven to be an excellent diagnostic tool for detecting middle ear structures, helping to achieve rapid and accurate diagnoses. Deep learning techniques are now widely used in CT scan‐based human medical image analysis, providing decision support and diagnostics. However, such techniques are currently underutilized in veterinary radiology. The focus of this study was to develop a deep learning model capable of diagnosing middle ear disease in dogs using CT images. To achieve this with a relatively small dataset, transfer learning and data augmentation techniques were applied. During the experimental phase of the study, we tested 10 binary classification models based on the ResNet architecture, combined with data augmentation and transfer learning, on a dataset consisting of a total of 535 canine CT images. We achieved a classification accuracy of up to 84.7%. The developed classifier, trained on relatively few CT images, can detect normal middle ears and middle ear disease in dogs with over 80% accuracy.

Fatigue-related subchondral bone injuries of the third metacarpal/metatarsal (McIII/MtIII) bones are common causes of wastage, and they are welfare concerns in racehorses. A better understanding of bone health and strength would improve animal welfare and be of benefit for the racing industry. The porosity index (PI) is an indirect measure of osseous pore size and number in bones, and it is therefore an interesting indicator of bone strength. MRI of compact bone using traditional methods, even with short echo times, fail to generate enough signal to assess bone architecture as water protons are tightly bound. Ultra-short echo time (UTE) sequences aim to increase the amount of signal detected in equine McIII/MtIII condyles. Cadaver specimens were imaged using a novel dual-echo UTE MRI technique, and PI was calculated and validated against quantitative CT-derived bone mineral density (BMD) measures. BMD and PI are inversely correlated in equine distal Mc/MtIII bone, with a weak mean r value of −0.29. There is a statistically significant difference in r values between the forelimbs and hindlimbs. Further work is needed to assess how correlation patterns behave in different areas of bone and to evaluate PI in horses with and without clinically relevant stress injuries.

Background: Fractures of the paracondylar process of the occipital bone may cause headshaking, neck pain and neurologic deficits. The condition is being recognised more frequently with increasing availability of computed tomography. However, to date only limited information is available as to presentation, treatment, surgical approach and outcome. Objectives: To describe the clinical signs, imaging findings, treatment, surgical approach and outcome in three horses diagnosed with paracondylar process fracture. Study design: Retrospective case series. Methods: Clinical records and diagnostic images of affected cases were reviewed. Results: Two cases had ventral nonunion fractures—one of these presented with neck pain, headshaking and behavioural changes, while in the other the fracture was a suspected incidental finding in a case of poor performance. A third case with a more dorsal fracture presented with acute facial nerve paralysis. Diagnosis was by computed tomography in all cases, although imaging of ventral fractures by radiography was found to be feasible. Where clinical signs could be associated confidently with the fracture, conservative management resulted in improvement but not complete resolution. Repeated recurrence of clinical signs after prolonged periods of remission necessitated surgical removal in one case, which was readily accomplished with the aid of ultrasound guidance, and led to rapid resolution of clinical signs without significant post‐operative complications. The surgical approach is described. Main limitations: Limited follow‐up was available. Conclusions: Paracondylar process fracture should be considered as a differential diagnosis for headshaking, neck pain, poor performance and facial paresis, and is a justification for performing computed tomography in such cases. A multi‐disciplinary approach is beneficial due to the potential for orthopaedic, neurologic, ophthalmologic and behavioural clinical signs, with additional need for expertise in diagnostic imaging and pain management. Surgical fragment removal should be considered for ventral fractures.

A 10-month-old pygmy goat was examined at the Royal (Dick) School of Veterinary Studies at the University of Edinburgh in January 2022, having been referred with a suspected diagnosis of a disorder of sexual development (DSD). The animal displayed a predominantly female phenotype (vulva with enlarged clitoris and vagina) but some male external characteristics such as a beard, larger body size, and larger horns. It also typically exhibits male behaviours such as mounting, aggression, and flehmen response. Computed tomography (CT) detected a bicornuated tubular fluid-filled structure connected to bulbous soft tissue masses. Subsequent exploratory laparotomy and reproductive tract removal identified underdeveloped uterine horns connected to ductus deferens and gonads, which were confirmed as testicles by histological examination. No spermatogenesis was detected, and no ovarian tissue was apparent. Blood levels of testosterone showed a marked decrease post-surgery (2.10 nmol/L to <0.03 nmol/L). Whole genome sequencing suggested that the patient may have an XY male karyotype, although cytological analysis was not possible to confirm the XY karyotype.