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The transmural ultrasound allows for the definition of the normal appearance of the hoof tissues and internal structures. Determining such measurements and proportions could contribute to evaluations of the normal spatial distal phalanx–hoof relationship. The objective was to describe the hoof’s dermis and epidermis measurements using the transmural technique, in comparison with DR and anatomical sections. Sixty-two healthy hooves without digital radiographic abnormalities, made up of 30 anatomical pieces (phase 1) and 32 alive horse hooves (phase 2), and 16 sagittal sections of the first ones were used. The proximal and distal planes were compared, defining the following measurements: coronary band-extensor process, distal phalanx apex–hoof wall, sole dermis, middle stratum, parietal dermis, lamellar layer, the sublamellar dermis, and ratios between them. Most of the measurements were consistent among methods. Some showed measurement differences and a minority was impossible to determine. The transmural technique allowed for the observation and replication of measurements of the hoof structures, described with other diagnostic aids. It also allowed for the implementation of new measurements that would help to determine the spatial location of the distal phalanx. Additionally, it contributes to the visualization of normal findings, which will be useful to compare variations in the different phases of laminitis.

Ultrasonography is commonly used to evaluate equine lameness-related structures, but traditional hoof approaches cannot adequately visualize internal structures such as the lamellar layer. To address this limitation, we used 62 healthy hooves without digital radiographic abnormalities, made up of thirty anatomical pieces (phase 1) and thirty-two hooves from living horses (phase 2). In both phases, half of the digits were submerged in water (group 1) and the other half in water and ice (group 2) for 24 h. Ultrasonographic views and temperature and humidity measurements were taken every two hours, and sagittal sections were obtained in phase 1. Good quality images were obtained in both phases. The transmural technique allowed the evaluation of several structures of the DEJ (tubular and lamellar strata of the hoof wall, sublamellar dermis, and solar and coronary papillae) and of the distal phalanx (extensor process, parietal surface, and apex). Our findings suggest that the transmural technique following hoof submersion can be useful for internal evaluation of hoof conditions, such as laminitis. However, further validation of the technique in natural or experimental cases is required.

Inflammation and apoptosis in the hoof lamellar interface both contribute to the early stages of sepsis-associated laminitis, but it is not clear whether apoptosis is occurring before the onset of inflammation or is being provoked by inflammation. Apoptosis and inflammation were therefore measured in lamellar tissues obtained at different time points throughout the early stages of experimentally induced laminitis. Apoptotic cells and leukocyte were enumerated in archived paraffin embedded lamellar tissue samples from previous experiments in which acute laminitis was induced using Black Walnut Extract (BWE) or starch (CHO). BWE-derived samples from 20 horses were allocated into four groups: Control (CON = 5); Early Time Point (ETP, 1.5 h after induction, n = 5); Developmental Time Point (DTP, 3-4 h after induction, n = 5); Obel Grade 1 (OG1, Onset of Lameness, n = 5). CHO-derived samples from 25 horses were allocated into four groups: CON (n = 8); DTP (10-12 h after induction, n = 6); OG 1 (n = 6); Obel 3 (OG3, lameness progression, n = 5). Apoptotic cells were enumerated using a horse validated TUNEL technique. Compared to controls, significant increases in apoptotic cell counts were not detected in lamellar epithelial cells during the developmental phase or at the onset of lameness during laminitis induction. A negative correlation between apoptosis and leukocyte infiltration was detected in the BWE model (P 0.05). In conclusion, apoptosis does not play an important role in the initial stages of sepsis-related laminitis.

Horse confinement is a common practice worldwide. However, preventing horses from grazing and denying them social interaction can compromise their welfare and lead to undesirable consequences. Considering the hypothesis that increasing the forage consumption time can lead to improved welfare, the objective of this study was to verify the effect of the implementation of a slow-feeder hay bag on the ethogram, motor activity, heart rate, and cortisol circadian rhythm (CCR) of stabled horses. Seven healthy horses were kept exclusively in individual stalls and fed pelleted feed, alfalfa hay, and Tifton hay. Horses were evaluated before the experiment and for 10 days foraging through a slow-feeder hay bag. The horses were monitored for 24 hours for ethogram and forage consumption time evaluations. The CCR was calculated by the percentage variance between the morning and afternoon serum concentration. A variation of 30% or less was indicative of poor welfare. The effect of time over the variables was verified by paired Student's t or Student-Newman-Keuls tests (P

This study evaluated the incidence of gastritis in foals subjected to different weaning management methods. Sixteen crossbreed foals [230 ± 35 kg], were enrolled in an experiment with a randomized block design. After weaning, foals were housed in either individual pens or a group pen. Gastritis in the foals was evaluated through gastroscopy. Data were submitted to analysis of variance by the non-parametric Friedman test at 0.05 significance level. Before weaning, gastritis was observed in 87.5% of the foals, and the scores for the number of gastric lesions were 2.10 and 1.56 for foals housed in group and individual pens, respectively. After weaning, the scores for the number of gastric lesions were 1.75 and 1.25 for foals housed in group and individual pens, respectively. For the intensity of gastric lesions, the average scores observed before weaning were 3.31 and 1.37 for foals housed in groups and individual pens, respectively. After weaning, the scores for the intensity of gastric lesions were 1.93 and 1.00 for foals housed in group and individual pens, respectively. The intensity of the gastric lesions decreased when comparing foals prior to weaning and after weaning, regardless of the management system (P.05). The number of lesions was not significantly different but tended to decrease after weaning. Differences in plasma cortisol concentrations were observed between samples collected on the weaning date and after weaning (P.05). No differences were detected in plasma gastrin concentration. In conclusion, gastritis in foals can be observed before weaning, which contributes to a decreased gastric lesion incidence.

The incidence of equine metabolic syndrome, a condition that results in endocrinopathic laminitis, is increasing worldwide. Although it is well known that the development of this syndrome depends on imbalances in energy metabolism and genetic traits, its pathophysiology remains unclear. Hydrogen nuclear magnetic resonance (1H NMR) is a powerful tool used to compare metabolic profiles and to discriminate metabolites in living beings. The aim was to apply this technology to detect blood biomarkers candidates in horses that were previously demonstrated to developed metabolic changes when subjected to induced obesity. Nine Mangalarga Marchador horses received a hypercaloric diet for 5 months and serum metabolomic analysis was performed before, during, and after the diet period. The 1H NMR results were subjected to multivariate analysis and NMR analysis allowed to identify six compounds (alanine, threonine, choline, α-glucose, β-glucose, and creatinine), and observe the increasing choline level over the assessment period in four animals. A hypercaloric diet altered the metabolic profile of horses, with an individual bias in the time at which these changes occurred. This study is the first to describe metabolomic compounds in Mangalarga Marchador horses subjected to a hypercaloric diet rich in non-structural carbohydrates.

Background With the hypothesis that equine dorsal lamellar tissue can be desensitized by anesthesia injection into distal interphalangeal joint (DIPJ), the objective was to assess the mechanical nociceptive threshold of hoof dorsal lamellae following intra-articular (IA) administration of lidocaine into this joint. Methods The DIPJ of the forelimbs of six adult healthy horses were injected with either 5 mL of lidocaine, or 5 mL of lactated Ringer’s solution. Treatments were randomly distributed, with each forelimb undergoing a single treatment. The hooves were evaluated pre- and post-injection at pre-selected times over 4 h, using a pressure algometry model. Mechanical nociceptive thresholds (MNTs) were recorded for the sole (dorsal, palmarolateral, and palmaromedial regions), coronary band (medial, lateral, and dorsal regions), heel bulbs (medial and lateral), and dorsal lamellar region (2 cm and 4 cm distal to the coronary band). The MNT means were compared over time using the Friedman test and between treatments using the Wilcoxon signed-rank test, with values of P Results There were no differences between treatments for any region of the hoof during the evaluation period. However, MNT values indicating analgesia were recorded in the dorsal lamellar region in 50% of hooves following adminstration of lidocaine into the DIPJ. Conclusion The administration of 5 mL of lidocaine into the DIPJ does not significantly increase the mechanical nociceptive threshold of the equine hoof.

Integration of genomic data with gene network analysis can be a relevant strategy for unraveling genetic mechanisms. It can be used to explore shared biological processes between genes, as well as highlighting transcription factors (TFs) related to phenotypes of interest. Unlike other species, gene&ndash, TF network analyses have not yet been well applied to horse traits. We aimed to (1) identify candidate genes associated with horse performance via systematic review, and (2) build biological processes and gene&ndash, TF networks from the identified genes aiming to highlight the most candidate genes for horse performance. Our systematic review considered peer-reviewed articles using 20 combinations of keywords. Nine articles were selected and placed into groups for functional analysis via gene networks. A total of 669 candidate genes were identified. From that, gene networks of biological processes from each group were constructed, highlighting processes associated with horse performance (e.g., regulation of systemic arterial blood pressure by vasopressin and regulation of actin polymerization and depolymerization). Transcription factors associated with candidate genes were also identified. Based on their biological processes and evidence from the literature, we identified the main TFs related to horse performance traits, which allowed us to construct a gene&ndash, TF network highlighting TFs and the most candidate genes for horse performance.

This study aimed to characterize and correlate physiological and metabolic changes in horses fed a hypercaloric diet (HD). Nine mature horses with a mean initial body condition score of 2.9 ± 1 (scale, 1-9) were fed a high-calorie diet for 5 months. Fasting blood samples were collected before the study and biweekly for the duration of the project to determine the concentrations of cholesterol (CHOL), very low (VLDL), low (LDL) and high-density (HDL) lipoproteins, triglycerides, non-esterified fatty acids, and fructosamine. A low-dose oral glucose tolerance test (LGTT) was conducted before, 75 and 150 days after HD introduction. Mean arterial blood pressure was measured monthly. Following HD introduction, CHOL, LDL, HDL, and fructosamine blood concentrations increased (P < 0.001). These four variables were also positively and significantly correlated with the blood insulin response to LGTT. These findings confirm the occurrence of hypercholesterolemia concomitantly with insulin dysregulation development in horses exposed to HD.

In recent years, several researchers have been studying obesity in national horse breeds; however, no studies demonstrating the dynamic of body and regional fat accumulation (adiposity) Mangalarga Marchador horses subjected to hypercaloric diets have been found. This study aimed to characterize the deposition of body and regional fat in horses with diet-induced weight gain. A total of nine Mangalarga Marchador adult horses with initial body condition score (BCS) of 2.9 ±1/9 (mean ±SD) were subjected to a hypercaloric, grain-rich diet for five months. Body weight and the following morphometric regional adiposity variables were analyzed: BCS, cresty neck scores (CNS), neck circumferences (NC) at 25, 50 and 75% of its length, and accumulation of subcutaneous adipose tissue at the base of the tail using ultrasonography (BTU). These data were collected at baseline and fortnightly after beginning the diet-induced weight gain until the end of the experiment. The effect of time on the variables was verified by analysis of variance (ANOVA) in randomized blocks or the Friedman’s test, and the means were compared by the Tukey’s test (p≤0.05). Exposure to hypercaloric diet promoted a mean weight gain of 27.45% (p

Insulin deregulation (ID) is a central player in the pathophysiology of equine metabolic syndrome (EMS), which is associated with generalized and/or regional obesity. The objective of this experiment was to characterize the alterations in the hormonal profile in horses exposed to a hypercaloric diet. A total of nine Mangalarga Marchador adult horses with initial body condition score (BCS) of 2.9±1/9 (mean±SD) were submitted to a high calorie grain-rich diet for 5 months. The data was collected before the start of the experiment and every 15 days until the end of the experiment and glucose and insulin concentrations were measured in the plasma. Proxies G:I, RISQI, HOMA-IR and MIRG were calculated. The low-dose oral glucose tolerance test (OGTT) was performed and the total area under the glucose (GTA) and insulin (ITA) curves at three different timepoints (before inducing obesity, after 90 days and after 150 days) was used. Analysis of variance of the results was performed considering the time effects and the means were compared with repeated measures by the Tukey’s test (P≤0.05). The ID was observed during the first 90 days of the experiment and was characterized as a decompensated ID, showing an increase of basal glucose and insulin plasma levels, changes in all proxies and a significant increase in GTA (P

RESUMO: Com o objetivo de estudar parâmetros indicativos de bem-estar, 30 equinos de corrida foram avaliados quanto ao temperamento, comportamento, parâmetros clínicos (condição geral, escoriações, escore corporal, cólicas no último ano, frequências cardíaca e respiratória) e níveis de cortisol plasmático (matutino, vespertino e ritmo circadiano). Todos os animais apresentaram boas condições físicas gerais, parâmetros clínicos normais para a espécie e não tiveram cólica no ano anterior ao estudo, demonstrando a preocupação dos tratadores com a saúde física dos animais. Contudo, 36,7% dos animais estudados apresentavam estereotipias. Apesar da alta incidência de indivíduos com ritmo circadiano do cortisol (RCC) alterado dentro do grupo de animais com comportamentos anormais (63,64%), não foi encontrada diferença estatística (P>0,05) quando comparado com a incidência do grupo de animais sem estereotipia (31,58%). Quatro animais com estereotipia portavam dispositivos para restringir a expressão de anomalias. Desses, todos apresentaram RCC alterado, permitindo demonstrar que equinos restringidos fisicamente de realizar sua estereotipia apresentam 18 vezes mais chances de ter alteração no RCC do que um animal de comportamento normal. Conclui-se que os equinos do Jockey Club do Paraná, apesar de apresentarem condições físicas satisfatórias comparados a estudos nacionais anteriores, possuíam alterações comportamentais e de função adrenocortical compatíveis com estresse crônico. Os achados também corroboram noções prévias de que a estereotipia é uma forma de tentar aliviar o estresse crônico em equinos, e que o uso de meios físicos para restringir sua manifestação aumenta a chance de distúrbios no metabolismo do cortisol.

Background To investigate the effect of different fixation strategies of the intramedullary interlocking nail (IIN) on the mechanical behavior of a polymeric implant applied for femoral fracture fixation in calves, and to evaluate the performance of a glass fiber-reinforced polymer applied in a bovine femoral fracture reduction system, five Holstein male animals with a mean weight (±SD) of 62.8 ± 20.4 kg and aged 74 ± 15 were used to generate biomechanical parameters for this study. Twelve models of the fractured bovine femur, simulating a simple oblique fracture, were developed for use during the simulations. The models were divided into three groups, with each group of four models being associated with a different fixation strategy. Models were used to simulate the loading conditions corresponding to a calf in the transition (decubitus position to static position) condition. The maximum stresses found in each set (bone/implant) were compared with the reference stresses of each nail material. Results Maximum implant stresses were found in the screws and at the interface between the screw and the nail. The performance of implants was influenced by the material and fixation strategy, which can be confirmed by the stress values found in the set. The analysis indicated that the composite nail is able to withstand the loading demands in all fixation strategies. Conclusions The finite element analysis (FEA) demonstrated that all polymeric materials analyzed provided sufficient resistance to withstand the loading forces imposed to the femur when an adequate blocking strategy was applied.

Background The objective was to evaluate the effects of regional perfusion of characterized mesenchymal stem cells derived from adipose tissue (Ad-MSC) in horses with chronic laminitis. Methods Six mares with stable chronic laminitis in standard treatment for distal phalangeal realignment were subjected to regional perfusion of the digital vein with Ad-MSC (20 million cells, 3 infusions every 15 days) in one forelimb compared to placebo infusion in the contralateral one. Evaluations occurred in two 30-day periods, before and after treatment (from the second infusion). Radiographs and digital venographs were performed on both thoracic limbs at the beginning and end of each period. Venography was evaluated by a vascular perfusion score system. The growth of the hoof capsule was monitored by the distance between the coronary band and a radiopaque marker inserted in the dorsal hoof wall. Radiographic spatial relationship between the distal phalanx and the hoof capsule was assessed by a specific software (Hoof Metron). Results Compared to baseline values, vascular perfusion was improved only in the Ad-MSC group (P Conclusion Ad-MSC therapy promoted improvements in digital blood perfusion, growth rate, and spatial relationship between distal phalanx and hoof capsule. Our results confirm the therapeutic potential of Ad-MSC in the treatment of horses with stable chronic laminitis. Improvements only in treated hooves reveals that infusions must be performed regionally in each of the affected limbs.

Only a few studies have examined the effect of neostigmine combined with lidocaine on epidural anesthesia in gelding horses. The purpose of this investigation was to evaluate clinical effects, ataxia, and the sensory block duration caused by adding neostigmine to epidural lidocaine in mares. Three independent treatments including neostigmine (NEOST), 2% lidocaine (LIDO), or 2% lidocaine combined with neostigmine (LIDO + NEOST) were administered to six mares using epidural catheters. Each animal received all treatments. A cutaneous pinprick nociception test with fine needle was used in perianal, sacral, and lumbar dermatomes in both antimeres. The response (attempt to kick, movement of the limbs, tail, or head toward the stimulus) was assessed immediately before and after each treatment (every 15 minutes in the first hour, and then every 30 minutes thereafter until the animal would go back to basal response). Analysis of variance ( P P > .05). No relevant changes in clinical and behavioral parameters were observed. In conclusion, adding neostigmine to lidocaine has not brought any relevant benefits to the epidural anesthesia in clinically normal mares.

RESUMO: Estudos prévios têm demonstrado alterações radiográficas em cascos de equinos obesos. Os objetivos foram estudar, com avaliação radiográfica, a relação espacial entre estojo córneo e falange distal de éguas jovens da raça Campolina com e sem obesidade. Foram utilizadas 22 éguas entre três e cinco anos de idade, sendo analisadas varáveis de adiposidade e medidas radiográficas dos cascos dos membros torácicos de éguas com escore corporal de 5 a 7/9 (Grupo Controle) e de 8 a 9 (Grupo Obeso). Foram feitas comparações entre os grupos e correlacionaram-se as variáveis de adiposidade entre si, variáveis adiposidade com variáveis casco e variáveis de casco entre si. Utilizou-se o teste t de Student para variáveis paramétricas e o teste Mann-Whitney para as não-paramétricas, para as medidas de correlação, utilizou o teste de Pearson para duas amostras paramétricas e o teste de Spearman para comparações que envolvam pelo menos uma variável não paramétrica (P

Clinical and pathological findings in a case of malignant tumor located in the nasal and paranasal sinuses of a six-year-old donkey are reported. The animal was referred to the Equine Veterinary Hospital after three years of progressively increasing facial swelling. Clinically, the animal presented with tachypnea, dyspnea, and wheezing in the laryngotracheal region. There was swelling in the frontal bone and left orbital regions with exophthalmos of the left eye and bilateral mucopurulent nasal discharge, as well as retropharyngeal lymph node enlargement. Radiographic examination revealed radiopacity in the left maxillary, frontal and nasal sinuses, and in the left orbital region. Endoscopy revealed an irregular mass in the nasopharynx. Computed tomographic images of the skull showed an irregular mass, of variable density, in the rostral region, extending from the nasal cavity to the conchofrontal sinus on the left side, with dorsal displacement of the septum and dorsal nasal meatus. Loss of definition and destruction of other osseous structures of the nasal cavity and the frontal bone, and hypodense areas at the encephalic periphery were evident. Computed tomographic scans were taken to identify the localization and extension of the mass. Fibrosarcoma was confirmed on the histopathological examination for the first time in this species. The tomographic scan was considered more effective than radiography Relata-se os achados clínicos, imaginológicos e patológicos em um muar de seis anos de idade com neoformação tecidual na região de seios nasais e paranasais. O paciente fora encaminhado ao Hospital Veterinário de equinos após três anos de progressão. Clinicamente, o animal demonstrava taquipneia, dispneia e alteração do ruído laringotraqueal. Observou-se aumento de volume no osso frontal e na região orbitária esquerda, acompanhado de exoftalmia do bulbo ocular ipsilateral, além de secreção nasal mucopurulenta bilateral. Os linfonodos retrofaríngeos estavam reativos. Ao exame radiográfico, foi constatado aumento da radiopacidade na região de seios maxilar, frontal, nasal e orbitário esquerdos. A tomografia computadorizada do crânio evidenciou uma massa tecidual de contorno irregular com densidade variável da região rostral da cavidade nasal até o seio conchofrontal esquerdo, com deslocamento do septo e do meato nasal dorsal. Além disso, ocorreu perda de definição e destruição das demais estruturas ósseas da cavidade nasal e do osso frontal, além de áreas hipodensas na periferia encefálica. Ao exame histopatológico, diagnosticou-se fibrossarcoma, pela primeira vez documentado na espécie. O exame tomográfico mostrou-se mais acurado quanto à extensão da lesão quando comparado ao exame radiográfico na cavidade nasal.

This study aimed to histologically evaluate the quality of tissue repair in equine suspensory ligament treated with two cell therapy protocols. All four limbs of six animals were operated simultaneously to remove a fragment in each ligament using a skin biopsy punch. Two days later, intralesional injections were performed using bone marrow mononuclear fraction (BM group), cultivated cells derived from adipose tissue (AT group), saline (positive control group), or no treatment (negative control group), in such way that each horse received all treatments. After sixty days biopsies were performed for histological analysis (H & E, Masson’s trichrome and picrosirius red) and immunohistochemistry analysis (collagen type III). Histological findings (H & E and Masson’s trichrome), birefringence intensity (through picrosirius) and collagen type III expression (through immunohistochemistry) were analyzed. Samples from treated groups had better birefringence intensity (P=0.007) and fiber alignment scores were superior compared to controls, though not statistically significant (P=0.08). Presence of inflammatory cells and intense staining for collagen type III occurred in all groups demonstrating an active healing process. In conclusion, both protocols resulted in improvement of tissue repair indicating their potential to be used as an adjuvant treatment of equine suspensory ligament disorders.

Background The objective was to evaluate the histological and immunohistochemical effects of regional perfusion of characterized mesenchymal stem cells derived from adipose tissue (Ad-MSC) in biopsy hoof samples from horses with laminitis. Methods Six mares with stable chronic laminitis in standard treatment for distal phalangeal realignment were subjected to regional perfusion of the digital vein with Ad-MSC (20 million cells, 3 infusions every 15 days) in one forelimb compared to placebo infusion in the contralateral one. Evaluations occurred in two 30-day periods, before and after treatment (from the second infusion). Dorsal hoof lamellar biopsies were taken 30 days before and 15 days after the therapeutic protocols. Histological 5-μm cuts stained with H&E and PAS were classified based on a crescent 1-5 scale lesion score system. The sum of each lesion grade represented the global lesion score. Immunohistochemistry for p63 positive cells were also performed in formalin-fixed samples. Results In the placebo limbs, there were increases over time in following histological variables: global lesion (P=0.01), keratinized axis loss (P=0.0001), stratum medium hyperplasia (P=0.001), primary epidermal lamellae homogeneity loss (P=0.003), and hyperkeratosis (P=0.05). Only the stratum medium hyperplasia score was increased in the Ad-MSC-treated hooves. P63-positive cells could be detected in all formalin-fixed paraffin-embedded samples, but background unspecific stain made counts imprecise to be made. Conclusion In conclusion Ad-MSC regional vascular perfusion prevented histological lesion progression in the lamellar tissue of horses with chronic laminitis. Our results confirm the therapeutic potential of Ad-MSC in the treatment of horses with stable chronic laminitis.

Mangalarga Marchador (MM) is a native Brazilian breed of “gaited” horses. Orthopedic lesions and conformation might affect the sport career of these animals. The aims of this study were to evaluate the tarsal angle and the prevalence of tarsal disease in healthy MM horses that had classified in the top seven positions at the 33rd National Mangalarga Marchador Breed Show in 2014. Fifty horses were included. Horses in category I were presented at hand and aged between 18 and 34 months; horses in category II were presented ridden and aged between 41 and 58 months. The tarsal angle was measured using an arthrogoniometer; lateromedial and dorsopalmar radiographs were taken and analyzed. Of the included horses, 70% had radiographic lesion, the most common disease was osteoarthritis of the distal tarsal joints. Radiographic lesions were detected in 65.38% of the horses in category I and in 75% of those in category II. The mean tarsal angle was 136.5 ± 4.90°, which indicates that high-performance MM horses in marcha picada contests have small tarsal angle. The prevalence of radiographic lesions among horses with tarsal angles ≥140° and ≤139° were compared. Male animals whose tarsal angle was equal to or above 140° were significantly more likely to have radiographic changes in the tarsus ( P = .0218). It was concluded that the prevalence of tarsal diseases in MM horses in marcha picada contests is high and that osteoarthitis of the distal interstarsal and tarsometatarsal joints are the most common.

We examined the hypothesis that the palmar digital nerves (PDNs), but not the dorsal branches (DBs) of the digital nerves, innervate the sensitive dorsal laminae of the equine foot by evaluating the effects of perineural anaesthesia of the PDNs and DBs separately on pain sensation evoked via mechanical stimulation of the dorsal laminae and other regions of the equine foot. Six clinically normal mares were used in a crossover design. A portable dynamometer was used to evaluate mechanical nociceptive thresholds at different points on the dorsal laminae, bulbs of the heel, coronary band and sole before and after the horses underwent perineural injection of PDNs or DBs with a local anaesthetic solution (treated group) or an isotonic saline solution (control group). Cornified tissue was removed from the sole and the dorsal aspect of the hoof wall before evaluations of mechanical nociceptive thresholds. Anaesthetising PDNs distal to the DBs increased mechanical nociceptive thresholds compared to baseline values (P

Resumo O objetivo deste estudo foi avaliar o reparo da cartilagem hialina equina, por meio de análises macroscópica (através de videoartroscopia) e histológica (através de fragmentos de biopsia), em defeitos condrais induzidos na tróclea lateral do fêmur tratados pela técnica de microperfurações subcondral associada ou não com administração intra-articular de cartogenina. Foram utilizados seis equinos pesando em média (±DP) 342±1,58 kg, com a idade aproximada de 7,2±1,30 anos e escore corporal de 7,1±0,75, que foram submetidos a videoartroscopia para indução da lesão condral de 1 cm2 na tróclea lateral do fêmur e realização da técnica de microperfuração do osso subcondral de ambos os joelhos. Foram realizadas quatro aplicações semanais com 20 μM de cartogenina intra-articulares em um dos joelhos (grupo tratado) e solução de ringer com lactato na articulação contralateral (grupo controle). Após o período de 60 dias, foram feitas as avaliações macroscópicas, através de videoartroscopias, e histológicas, através de biopsia. Não foram observadas diferenças significativas nos escores macroscópicos e histológicos para reparação condral entre animais dos grupos tratados e não tratados (P>0,05). De modo geral, a porcentagem média de cartilagem hialina no tecido de reparo (17,5%) foi condizente com a literatura internacional usando outros tipos de perfuração condral. Entretanto, não se observaram diferenças estatísticas entre grupos (P>0,05). A terapia com cartogenina, segundo protocolo utilizado, não produziu melhora do processo cicatricial em lesões condrais induzidas e tratadas com microperfurações na tróclea lateral do fêmur em equinos. Abstract The aim of this study was to evaluate the joint cartilage repair by macroscopic (via arthroscopy) and histological (biopsy fragments) analyses in chondral defects induced into equine femoral trochlea treated by microperforation associated with or without intra-articular administration of kartogenin. Six horses weighing 342±1.58 kg (mean ± SD), aged approximately 7.2±1.30 years and with a body condition score of 7.1±0.75, were used. The horses underwent arthroscopy for induction of 1-cm2 chondral lesions in lateral femoral trochlea immediately treated by microperforation of the subchondral bone of both knees. Four weekly intra-articular injections of kartogenin (20μM) in one knee (treated group) and Ringer lactate solution in the contralateral joint (control group) were performed during the postoperative period. After 60 days, macroscopic evaluations were performed by video-arthroscopy, and biopsy samples of the repair tissue were taken for histopathological healing evaluation. No significant change was observed in macroscopic and histological scores for chondral healing between treated and untreated groups (P>0.05). The overall mean percentage of hyaline cartilage in both groups (17.5%) was consistent with other international studies using other types of chondral microperforation; however, no statistical differences were observed between groups (P>0.05). In conclusion, the therapy with kartogenin, according to the used protocol, did not produce any macroscopic and histological healing improvement in induced chondral lesions treated with microperforations in equine femoral trochlea.

Laminitis is a severe podal affection, which pathophysiology remains partially renowned. Ischemic, enzymatic, metabolic and inflammatory mechanisms are connected to the development of laminar lesions. However, few therapeutic measures are effective to prevent or control the severity of acute laminitis and its prodromal stage, which often determines serious complications such as rotation and/or sinking of the distal phalanx and even the loss of hoof. The purpose of this study is to compile the actual knowledge in respect to the pathophysiology and treatment of equine laminitis.