Evaluating the Effect of Routine Hoof Trimming on Fore and Hind Hooves Impact Phase Kinetics.

Imbalances and altered kinetics of the hoof result in lameness in horses. Previously, studies have focused on the midstance phase of a gait, hence, available information on the impact phase is scarce. This study aimed to investigate the effect of hoof trimming on the fore and hindhooves at the impact phase of the walk. Our objective was to compare the kinetic variables of force (N), contact area (cm2), contact pressure (kPa), and peak contact pressure (kPa) before and after hoof trimming. Nine Arabian horses were walked straight over a pressure plate to collect the above kinetic variables for both left and right fore and hindhooves. The impact phase was defined as the first contact of each hoof with the pressure plate, which was collected as the first frame of data. The signed rank test was used to determine the difference of each kinetic variable between pre and post trimming for each hoof. A statistical P-value <.05 was considered significant. Routine hoof trimming of the forehooves did not significantly change the hoof kinetic variables, except for an increase of 56% (P = .0391) for contact area (CA) after trimming of the right forehooves. For the left hindhooves, force increased by 35% (P = .019) and CA increased by 18% (P = .039) after trimming. The data revealed how hoof trimming may affect hoof kinetics at the impact phase of the walk for this group of horses and demonstrates the need for further research in other breeds and disciplines.

Correlational Characteristics of Hoof Conformation and Midstance Kinetics at Walk.

Variations in hoof conformation may alter stress distribution, thus predisposing horses to pathologies and lameness; however, experimental studies are scarce. Our objective was to investigate the correlation between midstance hoof kinetics at the walk and hoof conformation in horses. Nine clinically sound, unshod horses were walked over a pressure plate, and force (F), contact area (CA), contact pressure (CP), and peak contact pressure (PCP) were recorded at the dorsal, palmar, medial, and lateral regions, as well as for the whole hoof. By using digital radiography and digital pictures, 55 variables of internal and external hoof shape and dimensions of the hoof were measured. Correlations between kinetic and anatomical measurements were investigated using Pearson correlation coefficient. P-values ≤ 0.05 and r values ≥ 0.5 were considered. Several anatomical variables showed correlations with biomechanical variables. Toe angle was negatively correlated with CA (r = -0.72). Several heel height measurements were negatively correlated with dorsal F (-0.59 ≤ r ≤ -0.50), suggesting a trend. Measurements of the dorsal hoof wall thickness and length/width of the distal phalanx showed correlations with F and CP (0.5 ≤ r ≤ 0.71). Our study was focused on midstance biomechanics and at the walk; further investigation on other gaits and parts of the stance phases is warranted. Patterns of correlations between internal structural arrangement and hoof kinetic parameters encourage more research and should be considered by veterinarian and farriers for routine and therapeutic trimming/shoeing.

Haematological profile in foals during the first year of life.

Foals' haematological values change constantly during their first year of life. The use of updated age-based reference intervals (RIs) is imperative for providing accurate diagnosis and optimum care for sick foals. The authors' objective was to provide updated RIs for 13 haematological values in 2, 7, 14, 30, 90, 180 and 365-day-old foals and to investigate the changes over time in each measured value. Venous blood was collected at those ages from clinically healthy foals. Thirteen haematological values were analysed. The 95% RIs were reported using a bootstrapping method. Differences over time were examined using Friedman test. RIs for each of the measured values were calculated. Results showed noticeable trends in changes over time in several values. Nevertheless, white blood cell counts significantly increased between day 2 and day 90 (P=0.011) while lymphocyte counts increased from day 2 up to day 180 (P=0.033). The mean corpuscular haemoglobin and mean corpuscular volume (P=0.011) significantly decreased between day 2 and day 90. Normal haematological values in foals not only differ from those in adult horses but also change throughout the first year of life; thus, it is critical that clinicians use age-based RIs when treating sick foals.

Hematological and serum biochemical profile values in pregnant and non-pregnant mares.

Pregnancy in many mammals, including mares, is associated with physiological changes that are reflected in hematological and biochemical profiles. Understanding those physiological changes and differentiating them from pathological changes is imperative for providing care and medical therapy in pregnant mares. Our objective was to compare normal hematological and biochemical profiles in healthy non-pregnant as well as healthy pregnant mares during the 1st and 2nd trimesters of pregnancy. Blood was collected by jugular venipuncture into ethylenediaminetetraacetic acid and serum tubes. Whole blood was analyzed using an ADVIA 120 hematologic analyzer and serum was analyzed using a Beckman Coulter AU5400. Statistical differences were detected using analysis of variance (ANOVA) and independent Student's t-test; P < 0.05 was considered significant. Results demonstrated higher red blood cell counts and hemoglobin concentrations and lower eosinophil counts (P < 0.001) in non-pregnant mares (n = 32) compared with pregnant mares at both 1st (n = 25) and 2nd (n = 17) trimesters. Biochemical analysis showed a significant decrease (P < 0.001) in albumin and blood urea nitrogen (P < 0.001) in the 2nd trimester and higher potassium levels (P = 0.03) in pregnant mares. Understanding such physiological changes is imperative to providing optimum care and medical treatment in mares. These data will assist clinicians to better evaluate and treat pregnant mares.

La gestation chez plusieurs mammifères, incluant les juments, est associée avec des changements physiologiques qui se reflètent dans les profils hématologiques et biochimiques. Comprendre ces changements physiologiques et les différencier des changements pathologiques est impératif afin de fournir les soins et thérapies médicales chez les juments gestantes. Notre objectif était de comparer les profils hématologiques et biochimiques chez des juments non-gestantes en santé ainsi que chez des juments gestantes en santé durant les 1er et 2e trimestres de gestation. Du sang fut prélevé par ponction de la veine jugulaire dans un tube avec anticoagulant (EDTA) ainsi que dans un tube pour sérum. Le sang entier fut analysé à l'aide d'un analyseur hématologiques ADVIA 120 et le sérum analysé avec un Beckman Coulter AU5400. Des différences statistiques furent détectées par analyse de variance (ANOVA) et par test de t indépendant de Student; une valeur de P < 0,05 était considérée significative. Les résultats montraient une augmentation du comptage d'érythrocytes et des concentrations d'hémoglobine plus élevées ainsi qu'un dénombrement d'éosinophiles plus bas (P < 0,001) chez les juments non-gestantes (n = 32) comparativement aux juments gestantes autant au 1er (n = 25) qu'au 2e (n = 17) trimestre. Les analyses biochimiques ont montré une diminution significative (P < 0,001) de l'albumine et de l'urée sanguine (P < 0,001) dans le 2e trimestre et des niveaux plus élevés de potassium chez les juments gestantes (P = 0,03). La compréhension de ces changements physiologiques est impérative afin de fournir les soins et traitements médicaux optimums chez les juments. Ces résultats aideront les cliniciens à mieux évaluer et traiter les juments gestantes.(Traduit par Docteur Serge Messier).

Changes in hoof kinetics and kinematics at walk in response to hoof trimming: pressure plate assessment.

Appropriate hoof preparation and symmetry are linked to the well-being of the horse. Previous studies have shown the efficacy of pressure plates (PPs) in delivering objective biomechanical analysis. We aimed to assess the effect of hoof trimming on hoof biomechanics using a PP. Nine clinically sound Arabian horses were walked across a PP while foot strike was recorded by a digital camera. Kinetic and kinematic parameters were recorded before and after trimming. Changes were considered significant when p ＜ 0.05. Vertical force (p = 0.026) and contact pressure (p = 0.006) increased after trimming. Stance-phase duration (p = 0.006), swing-phase duration (p = 0.023), and gait-cycle duration (p = 0.007) decreased significantly post-trimming. The observed changes in kinetic and kinematic parameters were related to hoof trimming. The reported results underline the importance of farriery practice and its effect on hoof biomechanics, which should be considered by both farriers and veterinarians.

Quantitative Analysis and Development of the Fore Feet of Arabian Foals from Birth to 1 Year of Age.

Objectives The goal of this study was to quantify external and internal anatomical characteristics of the foal foot throughout the first year of age. Methods Digital radiographs and photographs were taken bimonthly of the forefeet of nine Arabian foals, beginning at about 2 weeks of age until 12 months of age. Sixty-eight linear and angular variables were measured using NIH (National Institutes of Health) Image J software. Statistical analyses were performed using piecewise random coefficient model and p-values < 0.05 were considered significant. Results Distinct changes in hoof development were identified between 4 and 8 months of age. Distinct changes were identified in several external (conformational) measurements including hoof solar widths and lengths, palmar heel lengths, toe and heel angles and in several internal (radiographic) measurements including the widths and lengths of the phalanges and sesamoid bones as well as joint angles. Clinical Significance Existing knowledge of distal limb development in foals, particularly the foot, is limited. These findings define the measurable changes of the foal foot as it grows during the first year of life. These data provide an insight into the transformation of the hoof from its initial oval to a circular shape and from a club-like, cylindrical conformation to a more angled, conical conformation. This paper quantifies this development, ultimately allowing a better understanding of morphological changes in the foot of the growing foal.

Histological and functional characterizations of the digital cushion in Quarter horses.

The digital cushion (DC) plays a role in absorbing and dampening forces applied to the foot and therefore supports internal structures such as navicular bone; yet, its architecture is not well-known. The goal of this study was to characterize the microanatomical structure of the DC in horses with clinically sound hooves. Both forefeet from the cadavers of 12 adult Quarter horses were cut and sectioned and samples of the following 4 regions of the DC were obtained: axial proximal (AxProx), axial distal (AxDis), abaxial lateral (AbxLat), and abaxial medial (AbxMed). The samples were processed and stained with hematoxylin and eosin, Masson's trichrome, and Weigert's elastic stains. On each slide, 2 central 3- × 3-mm areas were microscopically assessed and all measurements were done within the 9-mm2 area. The number of detected collagen bundles, nerve fascicles, vessels, and the diameter of wall thickness and lumen of blood vessels were measured. Elastic fiber profiles were categorized based on relative density of elastic fibers detected in the field. The percentage of samples in which chondrocytes and adipose tissues were either present or absent was calculated. Significant structural differences were identified among the 4 regions of the DC. The AxDis region contained more collagen bundles (P < 0.0001) and less elastic fiber profiles than the AxProx region (P < 0.0001). The AxDis also contained more collagen bundles than the AbxMed and AbxLat (P < 0.0001) regions. Our findings provide insight into the structure of the DC of mature Quarter horses. The structural differences in the various regions of the DC are presumably related to the different functional properties of those regions; yet more research is warranted.

Le coussinet plantaire (CP) joue un rôle en absorbant et diminuant les forces appliquées au pied et par conséquent supporte les structures internes telles que l'os naviculaire; pourtant son architecture n'est pas très bien connue. Le but de la présente étude était de caractériser la structure micro-anatomique du CP chez des chevaux avec des sabots cliniquement sains. Les deux pattes avants provenant de 12 chevaux Quarter Horse furent coupées et sectionnées et des échantillons des quatre régions suivantes du CP obtenus : axial proximal (AxProx), axial distal (AxDis), abaxial latéral (AbxLat), et abaxial médial (AbxMed). Les échantillons ont été traités et colorés avec hématoxyline et éosine, trichrome de Masson, et coloration de Weigert pour les fibres élastiques. Sur chaque lame, deux zones centrales de 3 × 3 mm ont été évaluées en microscopie et toutes les mesures effectuées dans cette zone de 9 mm2. Le nombre de paquets de collagène, de faisceaux nerveux, et de vaisseaux sanguins a été déterminé ainsi que les diamètres de l'épaisseur de la paroi et de la lumière des vaisseaux sanguins mesurés. Les profils des fibres élastiques ont été catégorisés sur la base de la densité relative des fibres élastiques détectées dans le champ. Le pourcentage d'échantillons dans lesquels des chondrocytes et du tissu adipeux étaient présents ou absents a été calculé. Des différences structurelles ont été identifiées parmi les quatre régions du CP. La région AxDis contenait plus de paquets de collagène (P < 0,0001) et moins de profils de fibres élastiques que la région AxProx (P < 0,0001). La région AxDis contenait également plus de paquets de collagène que les régions AbxMed et AbxLat (P < 0,0001). Nos résultats donnent un aperçu de la structure du CP de chevaux Quarter Horse matures. Les différences structurales parmi les différentes régions du CP sont probablement liées aux différentes propriétés fonctionnelles de ces régions; mais plus de recherche sont requises.(Traduit par Docteur Serge Messier).

Response to acupuncture treatment in horses with chronic laminitis.

There is a need for evidence-based scientific research to address the question of the effectiveness of acupuncture in improving clinical signs of laminitis in horses. The objective of this study was to compare lameness levels before and after 2 acupuncture treatments in horses with chronic laminitis. Twelve adult horses with chronic laminitis received 2 acupuncture treatments 1 week apart. The points were treated using dry needling, hemo-acupuncture, and aqua-acupuncture. Lameness level was objectively evaluated using an inertial sensor-based lameness evaluation system (Lameness Locator), as well as routine examinations following American Association of Equine Practitioners scoring before the first and 1 week after the second acupuncture treatment. Data were analyzed using Wilcoxon signed-rank test and P-values < 0.05 were considered statistically significant. Both the Lameness Locator (P = 0.0269) and routine lameness examination (P = 0.0039) showed a significant reduction in lameness severity. Our results support using acupuncture, along with other treatment options, in treating chronic equine laminitis.

Réponse à un traitement à l'acupuncture chez des chevaux atteints de laminite chronique. Il existe un besoin de recherche scientifique factuelle afin d'aborder la question de l'efficacité de l'acupuncture pour améliorer les signes cliniques de la laminite chez les chevaux. L'objectif de cette étude consistait à comparer les niveaux de boiterie avant et après deux traitements d'acupuncture chez des chevaux atteints de laminite chronique. Douze chevaux adultes souffrant de laminite chronique ont reçu deux traitements d'acupuncture à 1 semaine d'intervalle. Les points ont été traités en utilisant des aiguilles, l'hémo-acupuncture et l'aqua-acupuncture. Le niveau de boiterie a été évalué objectivement en utilisant un système inertiel d'évaluation de la boiterie à base de sonde (repérage de la boiterie) ainsi qu'à l'aide d'examens de routine en se basant sur la notation de l'American Association of Equine Practitioners avant le premier traitement et 1 semaine après le deuxième traitement d'acupuncture. Les données ont été analysées en utilisant les tests de rang signés de Wilcoxon et des valeurs P < 0,05 étaient considérées comme étant significatives sur le plan statistique. Le repérage de la boiterie (P = 0,0269) et l'examen de routine de la boiterie (P = 0,0039) ont montré une réduction significative de la gravité de la boiterie. Nos résultats appuient l'utilisation de l'acupuncture, conjointement à d'autres options de traitement, pour traiter la laminite équine chronique.(Traduit par Isabelle Vallières).

Changes in hoof surface strain distribution in response to moderate exercise in Standardbreds.

OBJECTIVE: To quantify changes in hoof wall strain distribution associated with exercise and time in Standardbreds. ANIMALS: 18 young adult Standardbreds. PROCEDURES: 9 horses were exercised 4 d/wk for 30 to 45 minutes at a medium trot for 4 months; 9 nonexercised horses served as the control group. Rosette strain gauges were used to measure the principal surface strains at the toe, lateral quarter of the hoof wall (LQ), and medial quarter of the hoof wall (MQ) of the right forefoot at the beginning and end of the experiment. Midstance maximal (msϵ1) and minimal (msϵ2) principal and peak minimal principal (pkϵ2) surface strains were measured; SDs of each of those variables were also calculated. Results were compared through ANOVA of time and exercise effects between and within the groups. RESULTS: Both the exercised and nonexercised groups had changes in strain distribution in their hooves over time. The msϵ1 did not change significantly with exercise; however, it changed significantly in both groups at both hoof quarters over time. At the beginning of the study, mean msϵ2 and pkϵ2 values were significantly higher in the exercised group than in the control group at the MQ and LQ but not at the toe. At the end of the study, these values were significantly higher in the control group than in the exercised group at the toe but not at the MQ or LQ. CONCLUSIONS AND CLINICAL RELEVANCE: Detected changes in hoof wall surface strain may indicate the ability of hoof capsule material to respond to exercise. A better understanding of hoof adaptation to applied forces may allow implementation of proper trimming and shoeing techniques to promote adaptation to exercise loads in horses.

Changes in growth of the hoof wall and hoof morphology in response to regular periods of trotting exercise in Standardbreds.

OBJECTIVE: To quantitate changes in hoof wall growth and hoof morphology induced by mild exercise in Standardbreds. ANIMALS: 18 Standardbreds. PROCEDURES: Horses were exercised at approximately 6 m/s (4,200 to 5,600 m/d) on 4 d/wk for 17 weeks. Both exercise (n = 9) and nonexercise (control group; 9) groups were housed in a large paddock throughout the study. At the beginning and end of the study, right forelimb feet of all horses were digitally photographed and underwent magnetic resonance imaging. Hoof wall measurements were obtained from the images to evaluate hoof wall growth and morphometric variables. Data were compared between the groups and within each group via a quadratic model. Changes in each variable and pairwise correlations between variables were evaluated. RESULTS: Morphometric variables did not significantly differ between the control and exercise groups. However, differences within each group between the start and the end of the study were significant for several variables; overall, values for hoof wall variables increased and those for solar variables decreased. Between the beginning and the end of the study, the amount of variation in values of hoof capsule variables in the exercise group decreased to a greater extent, compared with control group findings. Patterns of pairwise correlations for variables differed between the groups. CONCLUSIONS AND CLINICAL RELEVANCE: In Standardbreds, mild exercise for 17 weeks caused no significant changes in hoof wall growth or morphometric variables. Subtle changes may develop in equine hooves in response to loading, and mild exercise may not be a strong adaptive stimulus.

Mechanical behavior and quantitative morphology of the equine laminar junction.

The horse's hoof is structurally modified for its mechanical functions, but studying the functional design of internal structures is hampered by the external keratinous capsule. Finite-element analysis offers one method for evaluating mechanical function of components within the capsule, such as the laminar junction. This is the epidermodermal connection that binds the hoof wall strongly to the distal phalanx. Primary epidermal laminae (PEL), projecting inward from the wall, vary in morphology and are remodeled despite being keratinous. The aim of this study is to investigate the suggestion that remodeling of PEL is influenced by mechanical stress. Circumferential and proximodistal stress distribution and relative displacement in the laminar junction are assessed by finite-element analysis (FEA) of nine hoof models. Spacing, orientation, and curvature of PEL are assessed from sections through 47 other hooves and compared with the stress and displacement data. Significant correlations are found between laminar spacing and seven displacement and stress variables, supporting the link between stresses and remodeling. Differences in external hoof shape cause regional variation in stress magnitudes around the laminar junction. This finding is in accord with previous observations that laminar morphology is individually regionally variable. This work provides the first concrete link between mechanical behavior and laminar morphology.