Endoscopy-assisted dacryocystorhinostomy in a dog.

Objective: To describe the use of an endoscope to assist in performing minimally invasive dacryocystorhinostomy in a dog to successfully manage a nasolacrimal duct cyst (dacryocyst).

Animal Studied: A 4-year-old female spayed American Staffordshire Terrier with chronic epiphora and swelling ventromedial to the nasal canthus of the right eye and reverse sneezing.

Procedures: Computed tomography revealed a fluid-filled cystic lesion of the right nasolacrimal duct with extensive nasal extension and secondary obstructive frontal sinusitis.

Caudoventral hip luxation in 160 dogs (2003-2023): A multicenter retrospective case series.

Objective: To describe patient characteristics, etiology, treatment outcomes and complications of caudoventral hip luxation (CvHL) in a large cohort of dogs and investigate factors associated with nonsurgical treatment outcomes.

Study Design: Multicenter retrospective case series.

Animal Population: A total of 160 client-owned dogs (170 limbs).

Cortical thickness adaptation to combined mechanical loading and parathyroid hormone treatments is site specific and synergistic in the mouse tibia model.

In this study, we aimed to quantify the localised effects of mechanical loading (ML), low (20 μg/kg/day), moderate (40 μg/kg/day) or high (80 μg/kg/day) dosages of parathyroid hormone (PTH), and combined (PTHML) treatments on cortical bone adaptation in healthy 19-week old female C57BL/6 mice. To this end, we utilise a previously reported image analysis algorithm on μCT data of the mouse tibia published by Sugiyama et al. (2008) to measure changes in cortical area, marrow cavity area and local cortical thickness measures (ΔCt.

Cortical bone adaptation response is region specific, but not peak load dependent: insights from CT image analysis and mechanostat simulations of the mouse tibia loading model.

The two major aims of the present study were: (i) quantify localised cortical bone adaptation at the surface level using contralateral endpoint imaging data and image analysis techniques, and (ii) investigate whether cortical bone adaptation responses are universal or region specific and dependent on the respective peak load. For this purpose, we re-analyse previously published CT data of the mouse tibia loading model that investigated bone adaptation in response to sciatic neurectomy and various peak load magnitudes (F = 0, 2, 4, 6, 8, 10, 12 N). A beam theory-based approach was developed to simulate cortical bone adaptation in different sections of the tibia, using longitudinal strains as the adaptive stimuli.

Cystoscopic-guided scissor transection of intramural ectopic ureters as a novel alternate minimally invasive treatment option to laser ablation in female dogs: 8 cases (2011-2020).

Objective: To evaluate the safety and efficacy of cystoscopic-guided scissor transection of ectopic ureters (CST-EU) in female dogs.

Animals: 8 incontinent female dogs with intramural ectopic ureters.

Procedures: For this retrospective case series, data were collected from medical records of dogs that underwent CST-EU to relocate the ectopic ureteral orifice to an anatomically normal trigonal location between June 2011 and December 2020.

Beam theory for rapid strain estimation in the mouse tibia compression model.

The mouse tibia compression model is a leading model for studying bone's mechanoadaptive response to load. In studying this mechanoadaptive response, (FE) modelling is often used to determine the stress/strain within the tibia. The development of such models can be challenging and computationally expensive.

Cortical Thickness Adaptive Response to Mechanical Loading Depends on Periosteal Position and Varies Linearly With Loading Magnitude.

The aim of the current study was to quantify the local effect of mechanical loading on cortical bone formation response at the periosteal surface using previously obtained μCT data from a mouse tibia mechanical loading study. A novel image analysis algorithm was developed to quantify local cortical thickness changes (ΔCt.Th) along the periosteal surface due to different peak loads (0N ≤ F ≤ 12N) applied to right-neurectomised mature female C57BL/6 mice.

Estimation of load conditions and strain distribution for in vivo murine tibia compression loading using experimentally informed finite element models.

The murine tibia compression model, is the gold standard for studying bone adaptation due to mechanical loading in vivo. Currently, a key limitation of the experimental protocol and associated finite element (FE) models is that the exact load transfer, and consequently the loading conditions on the tibial plateau, is unknown. Often in FE models, load is applied to the tibial plateau based on inferences from micro-computed tomography (μCT).

Mapping Regional Cortical Bone Responses to Local Changes in Loading and Systemic Stimuli.

Quantification of cortical bone mass and architecture using μCT is commonplace in osteoporosis and osteoarthritis research. Different groups often report substantially divergent mouse cortical bone responses to nominally comparable interventions. In the case of studies assessing bones' responses to externally applied loading, these differences are commonly associated with methodological differences in the loading regime.

Outcome after surgical management of canine insulinoma in 49 cases.

Canine insulinoma has historically been associated with a poor prognosis; however, prolonged survival times have recently been reported. Prognostic indicators that are available preoperatively are of limited predictive accuracy, and consensus on post-operative treatment recommendations is lacking. The objectives of this study were to describe outcomes in dogs with insulinoma treated surgically, and to assess whether selected potential risk factors are strongly associated with outcomes after surgery.

Urinary catheterisation of female dogs: a comparison between three techniques for catheter placement.

The objective of this study was to describe a new technique for urinary catheterisation of female dogs using a novel catheterisation device (NCD) and to compare the time taken to place a catheter using this technique with traditional techniques. A secondary objective was to survey participants on which of the techniques they preferred. Female canine cadavers of varying sizes were utilised and veterinary students who had not previously placed a urinary catheter were enrolled.

Bone gain following loading is site-specifically enhanced by prior and concurrent disuse in aged male mice.

The primary aim of osteoanabolic therapies is to strategically increase bone mass in skeletal regions likely to experience high strains. In the young healthy skeleton, this is primarily achieved by bone's adaptation to loading. This adaptation appears to fail with age, resulting in osteoporosis and fractures.

Student Perceptions of Sectional CT/MRI Use in Teaching Veterinary Anatomy and the Correlation with Visual Spatial Ability: A Student Survey and Mental Rotations Test.

Diagnostic imaging technology is becoming more advanced and widely available to veterinary patients with the growing popularity of veterinary-specific computed tomography (CT) and magnetic resonance imaging (MRI). Veterinary students must, therefore, be familiar with these technologies and understand the importance of sound anatomic knowledge for interpretation of the resultant images. Anatomy teaching relies heavily on visual perception of structures and their function.

Parathyroid hormone's enhancement of bones' osteogenic response to loading is affected by ageing in a dose- and time-dependent manner.

Decreased effectiveness of bones' adaptive response to mechanical loading contributes to age-related bone loss. In young mice, intermittent administration of parathyroid hormone (iPTH) at 20-80μg/kg/day interacts synergistically with artificially applied loading to increase bone mass. Here we report investigations on the effect of different doses and duration of iPTH treatment on mice whose osteogenic response to artificial loading is impaired by age.

Old age and the associated impairment of bones' adaptation to loading are associated with transcriptomic changes in cellular metabolism, cell-matrix interactions and the cell cycle.

In old animals, bone's ability to adapt its mass and architecture to functional load-bearing requirements is diminished, resulting in bone loss characteristic of osteoporosis. Here we investigate transcriptomic changes associated with this impaired adaptive response. Young adult (19-week-old) and aged (19-month-old) female mice were subjected to unilateral axial tibial loading and their cortical shells harvested for microarray analysis between 1h and 24h following loading (36 mice per age group, 6 mice per loading group at 6 time points).

Wnt16 Is Associated with Age-Related Bone Loss and Estrogen Withdrawal in Murine Bone.

Genome Wide Association Studies suggest that Wnt16 is an important contributor to the mechanisms controlling bone mineral density, cortical thickness, bone strength and ultimately fracture risk. Wnt16 acts on osteoblasts and osteoclasts and, in cortical bone, is predominantly derived from osteoblasts. This led us to hypothesize that low bone mass would be associated with low levels of Wnt16 expression and that Wnt16 expression would be increased by anabolic factors, including mechanical loading.

Quantification of Alterations in Cortical Bone Geometry Using Site Specificity Software in Mouse models of Aging and the Responses to Ovariectomy and Altered Loading.

Investigations into the effect of (re)modeling stimuli on cortical bone in rodents normally rely on analysis of changes in bone mass and architecture at a narrow cross-sectional site. However, it is well established that the effects of axial loading produce site-specific changes throughout bones' structure. Non-mechanical influences (e.

Disuse rescues the age-impaired adaptive response to external loading in mice.

Unlabelled: We aimed to determine whether aged bone's diminished response to mechanical loading could be rescued by modulating habitual activity. By reducing background loading, aged bone's response to loading increased to a level no different to young mice. This suggests, given the right stimulus, that ageing bone can respond to mechanical loading.

Androgens inhibit the osteogenic response to mechanical loading in adult male mice.

Androgens are well known to enhance exercise-induced muscle hypertrophy; however, whether androgens also influence bone's adaptive response to mechanical loading remains unclear. We studied the adaptive osteogenic response to unilateral in vivo mechanical loading of tibia in adult male mice in both a long- and a short-term experimental set-up. Mice were divided into four groups: sham operated, orchidectomized (ORX), T (ORX+T), or nonaromatizable dihydrotestosterone (ORX+DHT) replacement.

Planar cell polarity aligns osteoblast division in response to substrate strain.

Exposure of bone to dynamic strain increases the rate of division of osteoblasts and also influences the directional organization of the cellular and molecular structure of the bone tissue that they produce. Here, we report that brief exposure to dynamic substrate strain (sufficient to rapidly stimulate cell division) influences the orientation of osteoblastic cell division. The initial proliferative response to strain involves canonical Wnt signaling and can be blocked by sclerostin.

Sleep loss and the inflammatory response in mice under chronic environmental circadian disruption.

Shift work and trans-time zone travel lead to insufficient sleep and numerous pathologies. Here, we examined sleep/wake dynamics during chronic exposure to environmental circadian disruption (ECD), and if chronic partial sleep loss associated with ECD influences the induction of shift-related inflammatory disorder. Sleep and wakefulness were telemetrically recorded across three months of ECD, in which the dark-phase of a light-dark cycle was advanced weekly by 6 h.

Temporally separated bilateral anal sac gland carcinomas in four dogs.

Anal sac gland carcinoma arising from the apocrine secretory epithelium in the anal sac wall, is locally invasive and highly metastatic. The majority of anal sac gland carcinomas are unilateral on presentation, but bilateral tumours have been identified. This case series presents the outcome of four unique cases of unilateral anal sac gland carcinoma which subsequently developed contralateral anal sac gland carcinoma 50 to 390 days after removal of the initial tumour.

Ex vivo evaluation of the biomechanical effect of varying monocortical screw numbers on a plate-rod canine femoral gap model.

Objective: To compare the biomechanical behaviour of plate-rod constructs with varying numbers of monocortical screws applied to an ex vivo canine femoral-gap ostectomy model.

Sample Population: Twenty Greyhound dog cadaveric femurs.

Methods: Bone mineral density (BMD) was assessed with dual x-ray absorptiometry.

Aging differentially affects the re-entrainment response of central and peripheral circadian oscillators.

Aging produces a decline in the amplitude and precision of 24 h behavioral, endocrine, and metabolic rhythms, which are regulated in mammals by a central circadian pacemaker within the suprachiasmatic nucleus (SCN) and local oscillators in peripheral tissues. Disruption of the circadian system, as experienced during transmeridian travel, can lead to adverse health consequences, particularly in the elderly. To test the hypothesis that age-related changes in the response to simulated jet lag will reflect altered circadian function, we examined re-entrainment of central and peripheral oscillators from young and old PER2::luciferase mice.

A survey of surgical draping practices in small-animal practice in the UK.

Veterinary practices in the United Kingdom were surveyed to compare their surgical draping practices with Royal College of Veterinary Surgeons (RCVS) accreditation tier and other surgery-related factors. Using descriptive statistics and logistic or ordinal regression analysis (where appropriate), the relationships between draping material and accreditation tier and other surgery-related factors were assessed. Procedures were categorised as short or long.