Prevalence and WGS-based characteristics of Staphylococcus aureus in the nasal mucosa and pastern of horses with equine pastern dermatitis.

BACKGROUND: Many contributing factors are involved in the development of equine pastern dermatitis (EPD). Among the most frequently suspected is Staphylococcus aureus, known for its pathogenic potential in skin and soft tissue infections. We therefore investigated the association between S. aureus carriage and EPD. RESULTS: One hundred five EPD-affected horses and 95 unaffected controls were examined for the presence of methicillin-resistant and -susceptible Staphylococcus aureus (MRSA and MSSA) on the pastern skin and in the nostrils. S. aureus isolates were cultivated from swab samples on selective MSSA and MRSA chromogenic agar and identified using MALDI-TOF MS. Isolates were analysed by Illumina whole genome sequencing for genetic relatedness (cgMLST, spa typing), and for the presence of antimicrobial resistance and virulence determinants. A markedly higher proportion of samples from EPD-affected horses proved positive for S. aureus, both from the pastern (59.0 % vs. 6.3 % in unaffected horses; P<0.001), and from the nose (59.0 % vs. 8.4 %; P<0.001). Isolates belonged to 20 sequence types (ST) with lineages ST15-t084 (spa) (18 %), ST1-t127 (13 %), and ST1-t1508 (12 %) being predominant. Eight S. aureus were MRSA ST398-t011 and ST6239-t1456, and contained the staphylococcal cassette chromosome SCCmecIVa. Antimicrobial resistance genes were almost equally frequent in pastern and in nasal samples, whereas some virulence factors such as the beta-hemolysin, ESAT-6 secretion system, and some enterotoxins were more abundant in isolates from pastern samples, possibly enhancing their pathogenic potential. CONCLUSIONS: The markedly higher prevalence of S. aureus containing specific virulence factors in affected skin suggests their contribution in the development and course of EPD.

RADIOGRAPHIC MEASUREMENTS OF HOOF BALANCE ARE SIGNIFICANTLY INFLUENCED BY A HORSE'S STANCE.

Hoof balance radiographs are commonly used as the basis for corrective farriery decision-making in horses, however there are limited published data quantifying effects of the stance of the horse or the horizontal radiographic beam angle. In this analytical study, the influence of variation of the horse's stance in the craniocaudal and lateromodial plane on hoof balance measurements as well as the influence of variation of the horizontal radiographic beam angle on dorsopalmar hoof balance measurements was examined. Distal left thoracic limb lateromedial radiographs were acquired using a standardized protocol while varying the craniocaudal stance of five horses, each selected to be sound and conformationally normal. Dorsopalmar foot radiographs were acquired while varying the lateromedial stance; and variable angle horizontal beam dorsopalmar foot radiographs were acquired while keeping the limb position constant. Analyses of measurements demonstrated that hoof pastern angle had a linear relationship (R2 = 0.89, P < 0.001) with craniocaudal stance of the horse. The relationship of joint angle and stance was greater for the distal interphalangeal joint angle (R2 = 0.89, P < 0.001) than the proximal interphalangeal joint angle (R2 = 0.65, P = 0.001). The distal phalanx angle did not change with craniocaudal stance variation. The proximal interphalangeal joint width, distal interphalangeal joint width, or distal phalanx height did not change with lateromedial stance variation, nor within a 15 degree dorsolateral to caudomedial and dorsomedial to caudolateral variation from the dorsopalmar axis. Findings indicated that positioning of the thoracic limb needs to be considered during radiographic interpretation and decision-making for corrective farriery.

Does the proximal screw type affect stress and strain in pastern arthrodesis with locking plate in horses?

The implantation of unicortical cortex screws in the proximal hole of locking compression plates (LCP) has been recommended for proximal interphalangeal (PIP) arthrodesis in horses to prevent fractures resulting from stress risers in the proximal phalanx (P1). However, this cortex screw fixation technique may limit efficient dorsal compression of the PIP joint by the plate, potentially affecting the stability of the construct. In this study, we aimed to measure stress and strain in P1 and the plate using an ex vivo model of PIP arthrodesis in horses. We employed various implantation methods and proximal screw types in conjunction with two 5.5 mm transarticular cortex screws. Ten pairs of equine forelimbs were divided into four groups based on proximal screw placement: GUC (unicortically placed cortex screw), GBC (bicortically placed cortex screw), GUL (unicortically placed locking screw), and GBL (bicortically placed locking screw). We calculated the magnitude and direction of strain, strain ratio, and stress using strain gauges during an axial compression mechanical testing. The palmar surface of P1 exhibited higher stress and strains than the dorsal surface, with the plate part located at the articular level suffered more stress than the proximal part. Both the implantation method and proximal screw type significantly influenced the analyzed parameters. The GUC promoted greater changes in strain direction in the proximal portion of the P1. Bicortical placement of a cortex screw appears to be the most suitable option for filling the proximal hole of the LCP, because it allows effective dynamic compression via the plate and prevents abrupt shifts in the direction of the forces acting on the proximal part of P1 during loading.

Investigating Associations between Horse Hoof Conformation and Presence of Lameness.

Hoof trimming and shoeing determine the horse's hoof shape and balance. Hoof conformation plays a crucial role in limb biomechanics and can consequently prevent or predispose to injury. This study investigated the relationship between the morphometric characteristics of the horse's hoof, specifically, the dorsal hoof wall angle (DHWA), the coronet band circumference (CBC), and lameness in 73 horses categorised as undertaking either show jumping, dressage, or riding school activities. Results from logistic regression indicated that horses with either a combination of acute DHWA with large CBC, or more upright feet with larger DHWA and smaller CBC have higher probabilities of lameness. Show jumping and dressage horses showed a higher prevalence of lameness. Hoof morphometry should be monitored, and podiatric interventions should be regularly scheduled for the maintenance of correct hoof conformation to prevent injury. This study suggests that an aligned hoof-pastern axis managed by a DHWA of around 50 degrees may prevent lameness, with special emphasis on horses in dressage and show jumping activities. On the other hand, we can also speculate that the disturbed axis alignment of DHWA may be a cause of lameness.

Equine Pastern Dermatitis.

Equine Pastern Dermatitis (EPD) is not a single disease, but a cutaneous reaction pattern of the horse. EPD should be considered a syndrome, rather than a diagnosis. Uncovering the underlying etiology prior to treatment is key to minimizing treatment failures and frustration. To achieve a positive therapeutic outcome, treating the predisposing and perpetuating factors is just as important as addressing the primary cause of EPD. This article reviews clinical signs, differential diagnoses, diagnosis, and treatment of EPD.

Proximal Interphalangeal Arthrodesis in Horses: A Meta-Analysis of Retrospective Studies.

The aim of this study was to determine the clinical outcomes reported in retrospective studies of proximal interphalangeal arthrodesis (PIA) in horses through a meta-analysis of retrospective studies. CAB Abstracts, PubMed, ScienceDirect, Web of Science, and Scopus were searched. The primary outcomes included survival and surgical site infection (SSI) rates, return to activities, and time of hospital stay and casting. Subgroups were formed for fractures and other conditions. Meta-analyses were performed with fixed and random effects models to estimate proportions, mean values, and effect size by odds ratio (OR) with 95% confidence intervals (CI). Twenty-one full articles were included, totaling 458 horses. The survival rate was 90% (95% CI [86%-93%]), return to activities was 65% (95% CI [61%-70%]), and SSI was 12% (95% CI [8%-16%]). The mean hospitalization was 25 days (95% CI [18-35 days]) and time of casting was 29 days (95% CI [21-42 days]). The OR of survival (P = .769), return to activities (P = .576), and SSI (P = .467) were similar between cases of fractures and other conditions. PIA is an efficient and safe method to treat injuries in the pastern region, with a high survival rate and low SSI. However, the rate of return to soundness for intended use was modest, being potentially lower for fracture cases. Thus, investigations of more efficient interventions are needed to improve this outcome.

Perivascular wall tumour presenting as pastern mass in a Standardbred gelding.

A 2-year-old Standardbred gelding was referred for a mass on the palmaromedial right front pastern which was accompanied by progressively worsening lameness. The mass was firm to palpation and covered by normal skin. Ultrasonographically, a smooth encapsulated mass was present, medial to the flexor tendons and palmar to the neurovascular bundle. Because of a poor prognosis for future athletic performance without surgical or chemotherapeutic intervention and economic constraints preventing further diagnostics and treatment, the horse was euthanised. Post-mortem magnetic resonance imaging, histopathology and immunohistochemistry revealed the mass to be a perivascular wall tumour, the first record of such a neoplasia in the horse.

Evaluation of factors associated with surgical site infection in equine proximal interphalangeal joint arthrodesis: 54 cases (2010-2019).

BACKGROUND: The frequency of surgical site infection (SSI) following orthopaedic implant placement in horses has been reported but not compared with respect to specific antibiotic protocols administered. OBJECTIVES: To determine factors associated with SSI in horses undergoing proximal interphalangeal joint (PIPJ) arthrodesis including perioperative antibiotic protocols. METHODS: Records were evaluated (2010-2019), and horses undergoing PIPJ arthrodesis were identified. Patient signalment, supervising surgeon, reason for surgery, limb, implants placed, anaesthetic time, duration casting/coaptation postoperatively, antibiotic regimen and incidence/onset SSI were recorded. Bayesian and frequentist logistic regressions were used to estimate the contribution of covariates to infection occurrence. RESULTS: Fifty-four PIPJ arthrodeses were performed. SSI occurred in 2/54 (3.7%) on day 15,30. Arthrodesis was performed most commonly for osteoarthritis (33/54, 61.1%), fracture (11/54, 20.4%), and subluxation (5/54, 9.3%). Perioperative systemic antibiotics were administered 1-3 days (15/54, 27.8%) or > 3 days (39/54, 72.2%). Antibiotic protocols included cefazolin/gentamicin (20/54, 37%), cefazolin/gentamicin/doxycycline (14/54, 25.9%) and potassium penicillin/gentamicin (10/54, 18.5%). Regional limb perfusion was performed preoperatively 31/54 (57.4%) and postoperatively 7/54 (13%). Survival to dismissal was 98.1% (53/54 horses) with one horse euthanized due to support limb laminitis. No association was identified between antibiotic selection or duration (1-3 vs. > 3 days), pre-operative regional antibiotic perfusion, intraoperative antibiotic lavage or anaesthetic time (< or > 3 h) and SSI; however, modelling was complicated by quasi-complete or complete separation of the data. Bayesian analysis (but not frequentist analysis) indicated an association between post-operative regional antibiotic perfusion and SSI. Limitations include the retrospective nature of data collection and the low rate of infection overall. CONCLUSIONS: The prevalence of SSI in this population was lower than that in previous reports of equine orthopaedic internal fixation. There was no difference in SSI rate in cases administered systemic antibiotics for 1-3 days or >3 days, or for those horses that did or did not receive preoperative regional antibiotic perfusion.

Deep digital flexor tendon lesions in the pastern are associated with the presence of distal tendinopathy.

BACKGROUND: Correct diagnosis and characterisation of deep digital flexor tendon (DDFT) lesions in equine athletes allows targeted treatment and improved prognostication. OBJECTIVES: To assess the prevalence and character of pathological change within the DDFT in the pastern with concurrent tendon injury distally. It is hypothesised that tendon lesions in the pastern will be associated with tendinopathy within the hoof capsule. STUDY DESIGN: Retrospective descriptive case series. METHODS: Cases with DDFT lesions in the pastern and magnetic resonance imaging (MRI) or ultrasonography of the foot were evaluated retrospectively. Lesion location and type were recorded. Odds ratios were calculated to determine the associations between more distal tendinopathy and the presence of different DDFT lesion types in the pastern. RESULTS: Thirty-four MRI scans of 33 horses and 64 ultrasonographic exams of 58 horses were analysed. Lesion location and type were recorded. Distal DDFT lesions were found in 75% (95% CI: 66.0-84.0) of total cases of pastern DDF tendinopathy and in 97% (95% CI: 91.6-100.0) of cases with core lesions of the DDFT in the pastern. A core lesion in the pastern was significantly more likely (OR = 20.7, 95% CI: 2.2-191.0; P = .008) to be associated with injury in the foot than other types of pastern lesion. MAIN LIMITATIONS: MRIs of the foot were not obtained on all included limbs which did not allow for fully inclusive evaluation of DDFT lesions distal to the navicular bone. CONCLUSIONS: DDFT pathological change in the pastern, particularly core lesions, is associated with additional tendinopathy within the hoof capsule. When a DDFT lesion is found in the pastern, further imaging of the tendon within the foot is indicated to direct appropriate treatment and improve prognostication.

Owner reported clinical signs and -treatment decisions in equine pastern dermatitis.

INTRODUCTION: Equine pastern dermatitis has a high prevalence in the equine population, especially in draft breeds. This skin condition is difficult to treat, and it is suspected that owners often decide on a treatment without consulting a veterinarian. The objectives of this study were to describe owner-reported clinical signs, severity, and reasons to consult a veterinarian. Moreover, we inquired about preventive measures and treatments, both instituted by owners without previous consultation or prescribed by their veterinarians. A total of 123 horses (owners recruited over social media) were included in the study. All horses suffered from equine pastern dermatitis at least once in the two years preceding the study. Standardized questionnaires collecting information on management, housing conditions, clinical signs as well as preventive measures and treatments were filled out by participants. The data was recorded, and descriptive statistics were performed. Most horses (71 out of 115 available answers, 62 %) had shown clinical signs of equine pastern dermatitis at least four times in their lives. A total of 113 horses (92 % of all included horses) were affected by equine pastern dermatitis at the time of the interview. For 37 horses (32 %) out of 114 available answers the owners consulted their veterinarian only after the horse showed signs of pain or lameness. Usually, treatments that did not require a medical prescription were applied without consulting their veterinarian (e. g. only 9 % (14 out of 150 prescriptions) of topical creams promoting wound healing were prescribed by a veterinarian). A total of 31 treatment decisions (55 %) with creams containing anti-bacterial, anti-mycotic and/or anti-inflammatory agents and 100 % of systemic medications containing anti-bacterial, anti-parasitic or anti-inflammatory agents were prescribed by veterinarians. Overall, 69 % of treatment decisions were made without consulting a veterinarian, making it then more difficult to determine underlying causes for the pastern dermatitis and rendering the treatment often longer and more onerous. To raise owner awareness of possible consequences if a veterinarian is consulted too late in the disease process, specific information campaigns to improve animal welfare should be considered.

INTRODUCTION: La dermatite du paturon a une prévalence élevée dans la population équine, en particulier chez les races de trait. Cette affection cutanée est difficile à traiter et on soupçonne que les propriétaires décident souvent d'un traitement sans consulter un vétérinaire. Les objectifs de cette étude étaient de décrire les signes cliniques rapportés par les propriétaires, la sévérité et les raisons de consulter un vétérinaire. De plus, nous nous sommes renseignés sur les mesures préventives et les traitements, qu'ils soient mis en place par les propriétaires sans consultation préalable ou prescrits par leurs vétérinaires. Un total de 123 chevaux (propriétaires recrutés via les médias sociaux) ont été inclus dans l'étude. Tous les chevaux ont souffert de dermatite du paturon au moins une fois au cours des deux années précédant l'étude. Des questionnaires standardisés, recueillant des informations sur la gestion, les conditions de logement, les signes cliniques ainsi que les mesures préventives et les traitements, ont été remplis par les participants. Les données ont été enregistrées et des statistiques descriptives ont été réalisées. La plupart des chevaux (71 sur 115 réponses disponibles, 62 %) avaient présenté des signes cliniques de dermatite du paturon au moins quatre fois dans leur vie. Au total, 113 chevaux (92 % de tous les chevaux inclus) étaient atteints de dermatite du paturon équin au moment de l'entretien. Pour 37 chevaux (32%) sur les 114 réponses disponibles, les propriétaires ont consulté leur vétérinaire uniquement après que le cheval a eu montré des signes de douleur ou de boiterie. En général, les traitements qui ne nécessitaient pas de prescription médicale étaient appliqués sans consulter leur vétérinaire (par exemple, seuls 9 % [14 sur 150 prescriptions] des crèmes topiques favorisant la cicatrisation des plaies étaient prescrites par un vétérinaire). Au total, 31 décisions de traitement (55%) avec des crèmes contenant des agents antibactériens, antimycosiques et/ou anti-inflammatoires et 100% des médicaments systémiques contenant des agents antibactériens, antiparasitaires ou anti-inflammatoires ont été prescrits par des vétérinaires. Dans l'ensemble, 69 % des décisions de traitement ont été prises sans consulter un vétérinaire, ce qui rend plus difficile la détermination des causes sous-jacentes de la dermatite du paturon et rend le traitement souvent plus long et plus onéreux. Pour sensibiliser les propriétaires aux conséquences possibles d'une consultation trop tardive d'un vétérinaire dans le processus de la maladie, des campagnes d'information spécifiques visant à améliorer le bien-être des animaux devraient être envisagées.

Arthroscopic evaluation of the metacarpophalangeal and metatarsophalangeal joints in horses with parasagittal fractures of the proximal phalanx.

BACKGROUND: Fractures of the proximal phalanx are one of the most common long bone fractures of Thoroughbred racehorses. Although the degree of disruption and damage to the articular surface is generally considered a major prognostic determinant, associated arthroscopic findings have not previously been reported. OBJECTIVES: To describe the metacarpo/metatarsophalangeal (MCP/MTP) joint lesions associated with parasagittal fractures of the proximal phalanx arthroscopically identified at the time of fracture repair and compare radiographic and arthroscopic appearance of complete fractures. STUDY DESIGN: Retrospective case series. METHODS: Case records and arthroscopic images of horses with parasagittal fractures of the proximal phalanx admitted to Newmarket Equine Hospital from 2007 to 2017 were analysed. RESULTS: 81 MCP/MTP joints in 78 horses underwent arthroscopic evaluation concurrent to parasagittal fracture repair. Tears of the joint capsule and dorsal synovial plica were noted in 43 cases. Arthroscopy identified articular incongruity in three horses where fracture displacement was not predicted at all on pre-operative radiographs, and incongruity in additional plane(s) to the radiographic displacement in 14 horses. Concurrent osteochondral fragmentation and disruption of cartilage were present in some cases. MAIN LIMITATIONS: As a retrospective study, the arthroscopic data available for review were variable. Arthroscopic assessment of fracture reduction and joint congruency was evaluated in all cases but there was variation in the completeness of evaluation of the entire dorsal joint space of the fetlock joint. This may have led to the underestimation of soft tissue lesions in these cases. CONCLUSIONS: Some horses suffering from parasagittal proximal phalanx fractures have concurrent tearing of the joint capsule and/or dorsal plica, which may have relevance in the acute course of events resulting in the development of fractures. Fracture displacement and incongruency at the articular surface cannot confidently be excluded pre-operatively by radiographs alone.

Computed tomographic and radiographic morphology of the pastern and coffin joints of One-Humped Camel (Camelus dromedarius).

The objective of the current study was to describe the structures of the pastern and coffin joints in dromedary camel using x-ray, bone and soft tissue windows computed tomography (CT) and three-dimensional volume rendering (3DVR) of CT imaging. 3DVR of CT was obtained at the slight flexed dorsal view, plantar view, dorsolateral view and lateral view which explained all the surfaces and structures of the digit bony parts even the parts of the articular surface. The processed images of 3DVR of CT showed different patterns of the cortical, cancellous, subchondral bones and medullary cavity of the bones of the digits. The present study showed clearly all the hard and soft tissues in the pastern and coffin joints of the camel in CT images; however, the plantar ligaments of the pastern joint and ligaments of the navicular cartilage identified on CT images. The CT soft tissue window visualized the joint cavity and their pouches and tendon sheath of the flexor tendons better than the bone window CT. The radiographic, CT and 3D images could be used as a normal reference for the interpretation of some clinical diseases in the pastern and coffin joints of the camel.

Comparison of a 3-hole 4.5-mm Dynamic Compression Plate and a 7-hole 5.5-mm Y Locking Compression Plate for Arthrodesis of the Proximal Interphalangeal Joint in Horses-an Ex Vivo Biomechanical Study.

The objective of this study was to compare the biomechanical properties in a single cycle axial loading test and the types of failures in two constructs (a 3-hole 4.5-mm dynamic compression plate (DCP) and 7-hole 5.5-mm Y locking compression plate (Y-LCP)) in equine proximal interphalangeal joint (PIJ) arthrodesis. One limb in each pair was randomly assigned to PIJ arthrodesis using a 3-hole 4.5-mm DCP combined with two transarticular 5.5-mm cortical screws, whereas the contralateral limb was submitted to PIJ arthrodesis using a 7-hole Y-shaped 5.0-mm LCP in conjunction with one transarticular 4.5-mm cortical screw inserted through the central plate hole. Cortical screws were inserted in lag fashion. Constructs were submitted to a single axial load cycle to failure. Construct stiffness, load, and deformation were analyzed. Dynamic compression plate and Y-LCP arthrodesis constructs did not differ significantly and were equally resistant to axial loading under the conditions studied (DCP and Y-LCP group stiffness, 5685.22 N/mm and 6591.10 N/mm, respectively). Arthrodesis of the PIJ using a DCP and two transarticular 5.5-mm cortical screws or a Y-LCP yielded biomechanically equivalent outcomes under the test conditions considered. However, Y-LCP provides less impact in the palmar/plantar bone. Application of Y-LCP with unicortical screws has equivalent biomechanical characteristics of DCP and may be a safe option for PIJ arthrodesis, where potential trauma secondary to applying bicortical screws in the palmar/plantar aspect of the pastern can be avoided.

Normal anatomic reference of pastern and coffin joints in Egyptian buffalo (Bubalus bubalis): A compared atlas of cross-sectional anatomy, magnetic resonance imaging and computed tomography.

The purpose of this study was to describe normal magnetic resonance imaging and computed tomographic anatomy of pastern and coffin joints in Egyptian buffalo using cadaveric distal limbs. This study was achieved using twelve fresh cadaveric distal limbs from adult healthy buffaloes of both sexes. These cadaveric limbs were scanned using a 1 Tesla MRI scanner and CT scanner, injected with red latex, frozen at -20°C for 1 week, and then sectioned into sagittal, dorsal and transverse slices. The obtained MR and CT images were selected to be matched with their corresponding anatomical cross-sections for identification and evaluation of the clinically correlated anatomical structures of the pastern and coffin joints. The difference in signal intensities on CT and MRI scans amongst the tissues allowed clear differentiation of major bone and soft tissue structures of the pastern and coffin joints. CT provided a high spatial resolution of bone and soft tissue structures, however, MRI allowed a better and higher resolution and definition between soft tissues. The current study provided a normal CT and MRI anatomic reference which could help veterinary clinicians for interpretation and diagnosis of the clinically affected pastern and coffin joints in buffalo.

Parasagittal fractures of the proximal phalanx in Thoroughbred racehorses in the UK: Outcome of repaired fractures in 113 cases (2007-2011).

BACKGROUND: Thirty years have elapsed since the last published review of outcome following fracture of the proximal phalanx in Thoroughbred racehorses in the UK and contemporary results are needed to be able to advise of expected outcome. OBJECTIVES: Collect and analyse outcome data following repair of fractures of the proximal phalanx in Thoroughbred racehorses in the UK. STUDY DESIGN: Retrospective case series. METHODS: Case records of all Thoroughbred racehorses admitted to Newmarket Equine Hospital for evaluation of a parasagittal fracture of the proximal phalanx during a 5 years period were reviewed. Follow-up data regarding racing careers was collected for horses that underwent repair. Following exclusion of outliers, cases with incomplete data sets and comminuted fractures, mixed effect logistic regression was used to identify variables affecting returning to racing and odds ratios and confidence intervals calculated. RESULTS: Of 113 repaired cases, fracture configurations included short incomplete parasagittal (n = 12), long incomplete parasagittal (n = 86), complete parasagittal (n = 12) and comminuted (n = 3). A total of 54 (48%) cases raced after surgery. Horses that fractured at 2 years of age had increased odds of racing following surgery than those older than 2 years of age (OR 1.34; 95% CI 1.13-1.59, P = 0.002). Horses sustaining short incomplete parasagittal fractures had increased odds of racing following surgery compared with those with complete parasagittal fractures (OR 2.62; 95% CI 1.36-5.07, P = 0.006). No horses with comminuted fractures returned to racing. MAIN LIMITATIONS: Data are relevant only to Thoroughbred racehorses in the UK. CONCLUSIONS: Approximately half of the cases in this series raced following surgical repair. More 2-year-old horses raced following surgery, but this likely reflects horses, specifically older horses, passing out of training from unrelated factors. Fracture configuration affects odds of racing, which is relevant to owners when deciding on treatment.

Proximal interphalangeal arthrodesis in seven horses: A retrospective study in Brazil (2011-2019) / Artrodese interfalangeana proximal em sete equinos: um estudo retrospectivo no Brasil (2011-2019)

ABSTRACT: This study discussed several cases of proximal interphalangeal arthrodesis in horses at a veterinary hospital in Brazil. The medical records of seven horses that underwent proximal interphalangeal arthrodesis between 2011 and 2019 were analyzed for indication, technique, and complications. Short- and long-term outcomes were obtained from both the medical records and telephone interviews with the owners. A dynamic compression plate (DCP) was used in one of the seven horses that underwent surgical arthrodesis, and locking compression plates (LCP) were used in the others. Hospital discharge was recorded in 71.4% (5/7) of the horses, with an average hospital stay of 79 ± 45 days. Casting was maintained for 59 ± 26 days. Contact with owners was possible in four cases, two of which regained their prior level of function. The proximal interphalangeal arthrodesis may improve a horse's well-being, especially when it is considered an early intervention, minimizing the chances of immediate postoperative complications. Additional cases of surgical arthrodesis should be evaluated in long term to better characterize the outcomes of this procedure in Brazil.

RESUMO: Este estudo teve como objetivo apresentar e discutir casos de artrodese interfalangeana proximal em equinos atendidos em um Hospital Veterinário no Brasil. Os prontuários de sete equinos submetidos à artrodese interfalangeana proximal foram analisados quanto à indicação, técnica e complicações, entre 2011 e 2019. As informações sobre os desfechos de curto e longo prazo foram obtidas pela avaliação dos prontuário e entrevista telefônica com os proprietários. Em um dos sete cavalos submetidos à artrodese cirúrgica foi utilizado implantes DCP, e nos demais, LCP. A alta hospitalar foi registrada em 71,4% (5/7), com média de permanência hospitalar de 79±45 dias. A imobilização externa durou 59±26 dias. O contato com os proprietários foi possível em quatro casos, dos quais, em dois, os animais voltaram às suas funções. A artrodese interfalangeana proximal pode melhorar a qualidade de vida dos equinos, principalmente quando se considera a intervenção precoce, minimizando as chances de complicações pós-operatórias imediatas. Casos adicionais devem ser avaliados ao longo prazo para melhor caracterizar os resultados desse procedimento no Brasil.

Proximal interphalangeal joint arthrodesis in horses: concepts, indications, and techniques / Artrodese interfalangeana proximal em equinos: conceitos, indicações e técnicas

Surgical arthrodesis is effective for treating proximal interphalangeal joint (PIJ) injuries in horses. Despite several techniques described so far, the use of a 3-hole, 4.5mm-locking compression plate, associated with two 5.5-mm transarticular cortex screws, is currently considered the "gold standard." This review describes the anatomy of the pastern, as well as causes, indications, and possibilities for arthrodesis in the equine PIJ. A description of the current surgical technique for joint fixation is also presented.(AU)

A artrodese cirúrgica é efetiva para o tratamento de condições da articulação interfalangeana proximal (AIP) em equinos. Diversas técnicas são descritas, e o uso de uma placa de compressão bloqueada de três orifícios e 4,5 mm associada com dois parafusos corticais transarticulares de 5,5 mm é atualmente o padrão ouro. Esta revisão tem por objetivo descrever a anatomia da região da quartela, bem como as causas, indicações e possibilidades para a artrodese da AIP nos equinos. É apresentada também a descrição da técnica cirúrgica atualmente utilizada para realização da fixação da articulação.(AU)

Alopecia in the horse - an overview.

Dr Stannard explains different forms of alopecia in the horse with emphasis on the hair follicle and its function in the production of hairs. Both normal and abnormal patterns of hair growth and shedding in the horse are reviewed. Overviews of several specific hair follicle abnormalities, both inflammatory and noninflammatory, are discussed in detail with their clinical relevance. Some of the clinical entities covered in this section (linear alopecia and alopecia areata) are caused by immunological attack against normal structures and could have been placed in Immunologic diseases. However, because the clinical presentation for these entities is alopecia, Dr Stannard chose to include them in his notes on alopecia. Other inclusions in this section include cutaneous bacterial infections (e.g. pastern folliculitis and dermatophilosis) as well as fungal infections of the hair (dermatophytosis).

Miscellaneous.

This section includes clinical conditions which have unique characteristics which make them unsuitable for inclusion in the first six sections. The clinical description, aetiology and histopathologic findings of the unusual ear lesion, aural plaques, are described. Dermatoses complicated by, or caused by, photosensitivity are discussed in regards to their aetiology and pathogenesis as well as clinical features. The suggestion that photosensitization plays a role in the development of the lesions seen in pastern leukocytoclastic vasculitis is made. This section ends with an in depth discussion of the various causes of the nonspecific clinical entity known as 'grease heel', a chronic and often painful condition of the equine foot.

Effects of tenectomy of the medial head of the deep digital flexor on the hindlimbs of healthy horses / Efeitos da tenectomia da cabeça medial do tendão flexor digital profundo nos membros posterior de cavalos saudáveis

The tenectomy of the medial head of the deep digital flexor (TMHDDF) is a minimally studied surgery used in cases of dorsal subluxation of the proximal interphalangeal joint of the hindlimb in horses. The TMHDDF was evaluated in six healthy horses by the degree of lameness, perimeter of the surgical site, the angle of the distal articular joints, and the linear and angular measures of the hoof. Thus, TMHDDF of the right hindlimb was performed and the contralateral limb was used as a control. Both, right and left limbs were evaluated before surgery, as well as at 15, 30, and 60 days after surgery aiming to evaluate the effects of the surgical procedure in healthy limbs. Data were compared by analysis of variance regarding days and limbs. Values below the significant level (P< 0.05) were analyzed using the Tukey's test. TMHDDF caused a mild increase of the toe length and the height of lateral heel (0.2cm in both), as well as a decrease of the angle of the proximal interphalangeal joint (2°) when comparing the left hindlimb to the right hindlimb, 30 and 60 days after surgery. Overall, TMHDDF did not cause significant changes in the evaluated variables up to the 60 days of surgery.(AU)

A tenectomia da cabeça medial do flexor digital profundo (TCMFDP) é uma técnica cirúrgica pouco estudada, indicada para equinos com subluxação dorsal da articulação interfalângica proximal do membro pélvico. A TCMFDP foi avaliada em seis equinos hígidos no grau de claudicação; na perimetria da área operada; nos ângulos articulares distais; e nas medidas lineares e angulares de parâmetros dos cascos. Nesse sentido, foi realizada a TCMFDP do membro pélvico direito, permanecendo o esquerdo como controle. Ambos os membros foram avaliados nos momentos pré-operatório (0) e 15, 30 e 60 dias após a cirurgia, sendo objetivo avaliar os efeitos do procedimento cirúrgico em membros hígidos. Para comparação dos dados entre momentos e membros, foi realizada análise de variância. Os valores inferiores ao de significância (P<0,050) foram submetidos ao teste de Tukey. A TCMFDP provocou discreto aumento (0,2cm, em ambos) do comprimento de pinça e da altura do talão lateral e redução no ângulo da articulação interfalângica proximal (2°) na comparação com o membro pélvico esquerdo aos 30 e 60 dias após a cirurgia no contralateral. Em geral, a TCMFDP não causou alterações influentes nos aspectos avaliados até 60 dias do experimento.(AU)