Exploring the impact of high-energy diets on cattle: insights into subacute rumen acidosis, insulin resistance and hoof health.

Cattle lameness remains a significant concern, causing economic losses and compromising animal welfare. Claw horn lesions have been identified as a major cause of lameness in dairy cows but its correlation with high-energy diet and ruminal acidosis remains unclear. Hence, the primary objective of this study was to assess the effects of a high starch and a conventional diet on the rumen environment, acute phase proteins, and metabolic alterations, with a particular focus on insulin resistance and the consequent implications for the histology of the hooves in Holstein steers. Sixteen animals were divided into the high-starch (HS; 37% starch) and conventional (CON; 16.8% starch) groups. Glucose tolerance tests (GTT), blood, rumen fluid analysis, and histological evaluations of the hoof tissue were conducted over a 102-d experimental period. The HS group showed a lower ruminal pH than the CON group, and with values indicating subacute ruminal acidosis (SARA). The plasma glucose and IGF-1 concentrations were higher in the HS group, suggesting an anabolic state. Both groups exhibited an increase in the insulin area under the curve (AUC) after the GTT on d 102. Histological analysis of the hooves showed a reduction in the length and width of the epidermal lamella in both groups. There was a significant negative correlation between the insulin AUC and the length and width of the epidermal lamella. Since both groups were similarly affected, the hypothesis that histological alterations were caused by the experimental diets still needs confirmation. Additionally, the development of SARA was not essential for the observed histological changes in the hoof. Further studies are warranted to thoroughly investigate the role of insulin and IGF-1 imbalances in claw health.

In vivo evaluation of a polyester and fiberglass composite intramedullary nail for femoral osteosynthesis in calves.

The objective of this study was to test a composite of polyester resin and fiberglass in the form of an intramedullary nail for osteosynthesis of femoral fractures in calves. The methodology was established based on a previous study that used a bovine femur finite element model to simulate fractures, which were then stabilized by the same nails as proposed in this study. General anesthesia was induced in six calves followed by fracture creation via an oblique incision in the middle third of the femoral diaphysis, and osteosynthesis was immediately performed by retrograde insertion of the composite nail. Locking was achieved by drilling the bone and nail without using a jig and introducing two stainless steel screws proximal and two distal to the fracture line. Five of the six calves achieved complete fracture healing after 60 days. No signs of incompatibility or toxicity of the composite were observed. However, limitations were observed during the surgery, such as difficulty in drilling the nail and trimming the remainder portion of the nail that extended beyond the length of the bone. Small fragments produced by these maneuvers were considered irritating to soft tissues during the postoperative period. It was also found that small cracks in the nail tended to propagate in the form of longitudinal fractures. In conclusion, an intramedullary nail made of polyester resin and fiberglass (a low-cost and easy-to-acquire material) was considered biocompatible and capable of allowing bone healing of femoral fractures in young cattle. However, the development of solutions for the reported limitations is crucial prior to recommending the proposed composite for clinical use.

Comparison Between the Direct Method and Friedewald's Formula for the Determination of Low-Density Lipoprotein Cholesterol Serum Levels in Horses.

This study aimed to compare the use of enzymatic colorimetry and Friedewald's formula for the determination of LDL in horses. A total of 260 samples were used. Direct analysis was performed to determine low-density lipoprotein (LDL), high-density lipoprotein (HDL) cholesterol, triglycerides (TG), and total cholesterol (TC). The LDL level was calculated using the Friedewald equation (LDL= TC-HDL-TG/5). The correlations between the direct LDL analysis and the LDL calculated using the Friedewald formula were determined by Pearson's tests, and the coefficient of determination was also obtained by linear regression using SAS software (P<.05) and the kappa value. The mean value (± standard deviation) of the LDL was 22.12 (±10.34) mg/dL, and that of the result obtained by the Friedewald formula was 19.94 (±19.13) mg/dL. The correlation between the two variants analyzed in this experiment was significant, with a value of P < .001, and values of r = 0.688 and R2 = 0.4893. These results are relevant, given that recent studies have demonstrated a correlation between LDL plasma values and equine metabolic syndrome. Previous studies have reported discrepancies between the data obtained using Friedewald's method and the LDL-c values directly determined in humans and animals. The results of the present study suggest that the Friedewald method can be used to estimate the LDL plasma concentration in horses. Nevertheless, the coefficient of determination was not found to be adequate to recommend the Friedewald formula as a replacement for the enzymatic colorimetric method in determining LDL in horses.

Oral supplementation with Lithothamnion extract in horses subjected to oligofructose overload intake: effects on systemic inflammation and multiple organ function.

Systemic inflammatory response syndrome (SIRS) is a common condition in horses with gastrointestinal disorders. If not prevented or controlled, SIRS promotes multiple organ dysfunctions that may culminate in serious disabilities or even death. The objective of this study was to evaluate the effects of Lithothamnion supplementation on systemic inflammatory response and organ function variables in horses undergoing oligofructose overload (OFO) intake. Twelve healthy horses were randomly divided into control and treated groups. The treated group received Lithothamnion (100 mg/kg bw PO BID) for 7 days before oligofructose intake (10 g/kg PO). Horses underwent clinical and laboratory evaluation immediately before and 6, 12, 18, and 24 h following administration of oligofructose. Parametric data were subjected to ANOVA in randomized blocks, followed by Tukey, and Student's t-tests for mean comparsions. Non-parametric data were analyzed by the Friedman, Dunn's, and Mann-Whitney tests (P < .05). Systemic inflammation and organ dysfunction was evident in both groups; however, these changes were milder and delayed in the treated group. Supplementation attenuated and delayed the tachycardia, tachypnea, leukocytosis, hyperproteinemia, hyperbilirubinemia, hyperalbuminemia and hyperglycemia in treated horses undergoing OFO. Furthermore, increases in packed cell volume, red blood cells, hemoglobin, globulin, aspartate aminotransferase, alanine aminotransferase, gamma-glutamyl transferase, indirect and direct bilirubin and creatinine were observed only in the control group, remaining unchanged in the treated group. These findings demonstrate the potential of oral supplementation with Lithothamnion to ameliorate systemic inflammation and organ dysfunction in horses at risk of acquiring gastrointestinal disorders.

Apoptosis in epithelial cells and its correlation with leukocyte accumulation in lamellar tissue from horses subjected to experimental sepsis-associated laminitis.

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.

Changes in metabolic and physiological biomarkers in Mangalarga Marchador horses with induced obesity.

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.

Mechanical nociceptive assessment of the equine hoof following distal interphalangeal joint intra-articular anesthesia.

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 < 0.05 considered statistically significant. 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.

Identification and Functional Annotation of Genes Related to Horses' Performance: From GWAS to Post-GWAS.

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-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-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-TF network highlighting TFs and the most candidate genes for horse performance.

Adiposity and weight gain in Mangalarga Marchador horses subjected to hypercaloric diet / Adiposidade e ganho de peso em equinos Mangalarga Marchador submetidos a dieta hipercalórica

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<0.001). Significant values were observed for NC at 25 and 75% during the first 45 days of the experiment, and for NC at 50% during the first 30 days. BTU presented significant changes after 60 days, with an increase of 268% compared with the baseline value. These findings demonstrate the weight gain and the dynamic and magnitude of regional adiposity in Mangalarga Marchador horses subjected to hypercaloric diet.(AU)

Nos últimos anos vários pesquisadores têm estudado obesidade em raças nacionais, contudo não se encontram estudos que demonstrem a dinâmica do acúmulo de gordura corporal e regional em equinos marchadores submetidos a dietas hipercalóricas. O objetivo deste trabalho foi caracterizar a deposição de gordura corporal e regional em equinos com obesidade induzida. Foram utilizados nove equinos adultos, Mangalarga Marchador com escore de condição corporal (ECC) inicial de 2,9±1/9 (média±DP) submetidos a dieta hipercalórica por 5 meses. Foram avaliados o peso corporal, e as variáveis de adiposidade como o ECC, escore de acúmulo de gordura na crista de pescoço (ECP), circunferência do pescoço a 25%, 50% e 75% de seu comprimento e o acúmulo de gordura subcutânea na base da cauda por ultrassonografia (UBC). Coletados antes do início do experimento e quinzenalmente após o início da indução do ganho de peso. O efeito do tempo sobre as variáveis foi verificado por análise de variância em blocos ao acaso ou teste de Friedman e as médias foram comparadas pelo teste de Tukey (P≤0,05). O tratamento promoveu aumento médio de peso de 27,45% (P<0,001). Já as circunferências de pescoço 25% e 75% apresentaram valores significativos nos 45 dias de experimento e a circunferência a 50% se destacou nos primeiros 30 dias. A UBC apresentou alterações significativas aos 60 dias de experimento, com um acréscimo de 268% em relação ao valor basal. Tais achados demonstram o ganho de peso, a dinâmica e a magnitude do acúmulo de gordura localizada em equinos Mangalarga Marchador submetidos à dieta hipercalórica.(AU)

Insulin dysregulation in horses with induced obesity / Desregulação da insulina em equinos com obesidade induzida

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<0.001) and ITA (P<0.05). However, a clear compensation of the ID was evident after 150 days of experiment, which was supported by data from the insulin secretory response of ß cells of the pancreas that showed an increase in insulin plasma levels, after fasting or exposure to gastric glucose, with a concomitant decrease in fasting glucose and fructosamine levels, and a decrease of GTA and marked increase of ITA (P<0.0001) in the dynamic test. These findings confirm the occurrence of hyperinsulinemia associated with insulin deregulation in Mangalarga Marchador horses exposed to hypercaloric diets.(AU)

A desregulação insulínica (DI) é o ponto central dos mecanismos fisiopatológicos da síndrome metabólica equina (SME), que é associada à obesidade generalizada e/ou regional. O objetivo deste experimento foi caracterizar as alterações no perfil hormonal em equinos submetidos à dieta hipercalórica. Foram utilizados nove equinos Mangalarga Marchador adultos com escore corporal (EC) médio (±DP) inicial de 2,9±1 (escala de 1-9) submetidos à dieta hipercalórica atingindo um EC de 8,3±1 após cinco meses. Os dados foram coletados antes do início do experimento e com o intervalo de 15 dias até o final do experimento, os valores plasmáticos foram obtidos para mensuração das concentrações de glicose e insulina. Foram calculados os proxies G:I, RISQI, HOMA-IR e o MIRG. Foi realizado o teste de baixa dose de glicose oral (TBDGO) utilizando a área total sob a curva de glicose (ATG) e insulina (ATI) em três momentos, antes da indução a obesidade, após 90 e 150 dias. Os resultados foram submetidos à análise de variância considerando-se os efeitos de tempo e as médias comparadas com medidas repetidas pelo teste de Tukey, com o valor P≤0,05. A DI foi observada nos primeiros 90 dias de experimento, se caracterizando como um quadro de DI descompensada, apresentando um aumento dos níveis plasmáticos basais de glicose e insulina, pelas alterações em todos os proxies e com um aumento significativo da ATG (P<0,001) e ATI (P<0,05). Contudo, ficou evidente uma compensação do quadro de DI após 150 dias de experimento, sendo demonstrado pelos dados da resposta secretória insulínica das células ß do pâncreas, que se manifestaram pelo aumento dos níveis plasmáticos de insulina pós-jejum ou exposição à glicose gástrica com concomitante redução nos níveis de glicose e frutosamina pós-jejum e pela redução da ATG e pela marcada elevação de ATI (P<0,0001) no teste dinâmico. Tais achados comprovam a ocorrência de hiperinsulinemia associada à desregulação insulínica em equinos Mangalarga Marchador expostos a dietas à dieta hipercalórica.(AU)

Bem-estar em equinos do Jockey Club do Paraná: indicadores clínicos, etológicos e ritmo circadiano do cortisol / Welfare in horses of the Jockey Club Paraná: clinic ethologic indicators and circadian rhythm of cortisol

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.(AU)

The objective was to study indicative parameters of welfare in 30 race horses evaluated for temperament, behavior, clinical parameters (general condition, abrasions, body score, colic in the last year, heart and respiratory rates) and plasma cortisol levels (morning, afternoon and circadian rhythm). All animals presented good general physical condition, normal clinical parameters for the species and no colic episodes in the year preceding the study. However, 36.7% of animals had stereotypies. Despite the high incidence of altered circadian cortisol rhythmicity (CCR) within the group of animals with abnormal behavior (63.64%), there was no statistical difference (P>0.05) when compared with the incidence in the group animals without stereotyping (31.58%). Four animals with stereotypic behavior carried devices to restrict the expression of anomalies. All these four individuals had altered CCR, showing that restricting the stereotypic behavior of a horse increases 18 times the chances of altered CCR when compared to an individual with normal behavior. The horses of the Jockey Club of Paraná, despite having good physical condition compared to previous national studies, had behavioral and adrenocortical function consonant with chronic stress changes. The results also corroborate previous concepts of stereotyping as stress relieving in horses, and that the use of its physical restriction increases the chances of disturbances in cortisol metabolism.(AU)

Testing a new surgical instrument to obtain bovine hoof biopsy samples / Teste de viabilidade de um instrumento cirúrgico para obtenção de biópsias do tecido laminar do casco de bovinos

The histological and molecular analysis of biopsy samples are fundamental steps for the understanding of physiopathology, diagnosis and prognosis of the diseases. However, harvest of tissue biopsies from hoof lamellar tissue is a procedure with limitations due to lack of effective surgical instruments and techniques. The aim of the current study is to develop and test in vivo a surgical instrument with the specific purpose of harvesting lamellar tissue in cattle. A prototype called Falcão-Faleiros' lamellotome (INPIBR102013018765-8) was designed, produced and tested. After sedation, five adult cattle were restrained in lateral recumbency and locally anesthetized in two digits. The stratum corneum was worn down using a rotary tool coupled to a 3/8" high-speed cutter until the soft tissue proximity was reached. Next, the inner edge of the worn area was bounded with a scalpel. The lamellotome was introduced to obtain and hold the sample. The histological specimens of 16mm length by 6mm depth were stained with HE, PAS, Masson's thricome and Shorr. The structures of interest were differentiated in the histological analysis without technical artifacts and a mean number of 85 epidermal laminae per sample were counted. No relevant lameness or wound complication were seen following the procedure. In conclusion the technique using the lamellotme was effective in obtaining lamellar tissue biopsy samples without causing clinical harm in cattle. The procedure showed potential to be used in clinical research or even as a supplementary diagnosis method for routine bovine podiatry.(AU)

A avaliação das propriedades histológicas e da expressão de genes e proteínas em biópsias tem sido determinante para o entendimento da fisiopatologia, o diagnóstico e o prognóstico das enfermidades. Entretanto, a obtenção de biópsias do casco é um procedimento com limitações devido à ausência de técnicas e instrumentos específicos. O objetivo foi desenvolver e testar, na espécie bovina, um instrumento cirúrgico especificamente desenvolvido para realização de biópsias de casco nominado lamelótomo de Falcão-Faleiros (INPI, BR102013018765-8). Utilizaram-se cinco bovinos adultos que foram sedados, contidos em decúbito lateral e tiveram dois dígitos anestesiados. Em seguida, uma serra circular acoplada a uma microretífica foi usada para o desgaste do estrato córneo na parede dorsal até próximo do estrato lamelar. Após incisões retilíneas delimitando a borda interna da área desgastada, utilizou-se o lamelótomo para obtenção da amostra. Os fragmentos de 16mm de comprimento e 6mm de profundidade foram fixados em formalina e processados para histologia com colorações HE, PAS, Shorr e tricrômico de Masson. Nenhum dos animais apresentou claudicação ou complicação relevantes no período pós-opertório. As amostras foram consideradas adequadas quanto à integridade das lâminas e à preservação de sua arquitetura. Obtiveram-se média de 85 lâminas epidérmicas viáveis por biópsia. Conclui-se que o lamelótomo de Falcão-Faleiros é apropriado e seguro para a obtenção de biópsias de casco em bovinos, se mostrando promissor para uso em estudos clínicos e na rotina de diagnóstico de problemas podais em bovinos.(AU)

The influence of nail blocking conditions in cattle femoral fractures.

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 ±â€¯20.4 kg and aged 74 ±â€¯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.

Caudal epidural anesthesia in mares after bicarbonate addition to a lidocaine-epinephrine combination.

OBJECTIVE: To investigate the nociceptive and clinical effects of buffering a lidocaine-epinephrine solution with sodium bicarbonate in caudal epidural block in mares. STUDY DESIGN: Prospective randomized controlled trial. ANIMALS: Six mixed-breed mares weighing 350-440 kg. METHODS: Each animal was administered two caudal epidural injections, 72 hours apart, using different solutions prepared immediately before injection. The control solution was 7 mL 2% lidocaine hydrochloride with epinephrine hemitartrate (1:200,000) added to 3 mL sterile water for injection (pH 2.9). The alkalinized solution was 7 mL of lidocaine-epinephrine solution added to 2.3 mL sterile water for injection and 0.7 mL 8.4% sodium bicarbonate (pH 7.4). Nociception was evaluated by response to skin pinching at 31 sites in the sacral region and around the perimeter of the anogenital area (distances of 10, 15 and 20 cm) before, and 5, 10 and 15 minutes after epidural injection, then every 15 minutes until the return of nociception in all evaluated sites. The onset and duration times, and intensity of ataxia (grades 0 to 3) were recorded. The paired t test was used to compare the onset and duration of anesthesia and ataxia (p<0.05). RESULTS: Alkalization of the solution resulted in significant decreases in the average time of onset of loss of nociception in the sacral region (40%) and around the perimeter of the anogenital area extending up to 5 cm (36%) and from 5 to 10 cm (32%) from the anus and vulva. Alkalization also decreased the average duration of ataxia (33%), without affecting the duration and extent of anesthesia or the degree of ataxia. CONCLUSIONS AND CLINICAL RELEVANCE: Alkalization of lidocaine-epinephrine solution is advantageous in shortening the duration of ataxia and hastening the onset of anesthesia in areas adjacent to the anogenital area, without reducing the duration of epidural anesthesia, in mares.

Relação espacial entre a falange distal e o estojo córneo em éguas Campolinas jovens com e sem sinais de obesidade / Spatial relationship between the distal phalanx and the hoof capsule in young Campolina mares with and without obesity

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<0,05). Os resultados demonstraram que éguas Campolinas obesas, ainda jovens, já apresentam indícios de alteração na relação espacial entre estojo córneo e falange distal.(AU)

Previous studies have demonstrated radiographic changes in the hoof of obese horses. The objective was to study through radiographic evaluation the spatial relationship between the hoof capsule and the distal phalanx of Campolina mares with and without obesity. Twenty-two Campolina mares 3 to 5 years old were used. We analyzed adiposity variables and radiographic measurements of the hoof of both forelimbs of mares with body condition score from 5 to 7/9 (Control group) and from 8 to 9 (Obese group). Comparisons were made between groups using the Student t test for parametric variables and the Mann-Whitney test for the nonparametric ones. Pearson or Spearman tests were used to evaluate the correlation among parametric and nonparametric variables respectively (P<0.05). Evidences of changes in the spatial relationship between the hoof capsule and the distal phalanx were observed in obese Campolina young mares.(AU)

Administração seriada de salina hipertônica 7, 5% na terapia para sepse grave decorrente da síndrome da diarreia hemorrágica aguda em cães / Serial administration of 7. 5% hypertonic saline solution in the therapy of severe sepsis due to acute hemorrhagic diarrhea syndrome in dogs

Na clínica de animais de companhia é frequente cães com síndrome da diarreia hemorrágica aguda associada a quadros de sepse, o que acarreta alta mortalidade. Nesse contexto, objetivou-se, em um ensaio clínico controlado aleatorizado de centro único, estudar os efeitos tardios da solução salina hipertônica a 7,5% em aplicações seriadas, sobre variáveis hemodinâmicas, clínicas e laboratoriais em cães com quadro de sepse grave decorrente desta síndrome. Para tal, 12 cães foram aleatoriamente distribuídos em dois grupos de igual número, sendo um controle (CON) e o outro, solução salina hipertônica 7,5% (SSH). Variáveis clínicas e laboratoriais foram avaliadas imediatamente após a admissão do paciente (T0), 24 (T24), 48 (T48) e 72 (T72) horas após a admissão. O grupo SSH recebeu Ringer com lactato, antibioticoterapia, analgésico e SSH 7,5% em bolus (5mL kg-1 em 4 minutos) no T24 e no T48. O grupo CON recebeu a mesma terapia acima, porém ao invés da utilização de SSH a 7,5%, administrou-se bolus de solução de Ringer lactato na mesma dose e tempos utilizado. As avaliações em cada tempo foram realizadas anteriormente à administração dos bolus, nos dois grupos. Avaliaram-se hemograma completo e as variáveis clínicas (escala AVDN, grau de desidratação, frequência respiratória e temperatura retal), frequência cardíaca (FC), pressão arterial sistólica (PAS). Os dados paramétricos foram avaliados pelos testes Student Newman Keuls e teste t de Student, e os não paramétricos pelo teste de Friedman e Mann Whitney, com nível de significância de P≥0,05. Nas variáveis clínicas estudadas não se observou diferença entre os grupos e entre os momentos avaliados. Observou-se diferença significativa no grupo SSH no T72, com elevação da PAS e redução da FC, fato não observado no grupo CON, onde esses parâmetros não se alteraram. O hematócrito e a concentração de hemoglobina diminuíram em ambos os grupos com o tempo. As contagens dos leucócitos totais e dos monócitos apresentaram uma elevação significativa no grupo SSH, estando os leucócitos dentro da faixa de normalidade no T72. Não houve diferenças significativas em relação aos neutrófilos segmentados, porém no grupo SSH verificou-se aumento de 9,5 vezes no T72 comparado com o T24 (P=0,09), enquanto que este aumento foi de apenas 2,5 vezes no grupo CON (P=0,30). Observou-se ainda redução nas contagens de plaquetas e na concentração de globulinas no grupo COM, enquanto essas variáveis se mantiveram estáveis no grupo SSH. Conclui-se que a administração seriada de SSH 7,5% se mostrou promissora no tratamento de cães com síndrome da diarreia hemorrágica aguda, pois auxilia na estabilização dos leucócitos, plaquetas e globulinas de cães com sepse grave decorrente da síndrome da diarreia hemorrágica aguda.(AU)

The association between acute hemorrhagic diarrhea syndrome and sepsis is frequent in dogs and causes high mortality. In this context we investigated in a randomized single-center controlled trial the late effects of 7.5% hypertonic saline solution in serial applications on hemodynamic, clinical and laboratory variables in dogs with severe sepsis due to the syndrome. Twelve dogs were randomly distributed into two groups of equal numbers, control (CON) and 7.5% hypertonic saline solution (SSH). Clinical and laboratory variables were evaluated immediately after admission of patients (T0), 24 (T24), 48 (T48) and 72 (T72) hours after the admission. The SSH group received Ringer with lactate, antibiotic therapy, analgesic and 5mL/kg-1 bolus of 7.5% SSH over 4 minutes on T24 and T48. The CON group received the same therapy, but instead of 7.5% SSH, Ringer with lactate bolus was given at the same dosis and times. All evaluations were performed prior to the administration of the bolus in both groups. Data collection included complete blood count and clinical variables (AVDN scale, degree of dehydration, respiratory rate and rectal temperature), heart rate (HR) and systolic blood pressure (SBP). Parametric data were evaluated by the Student Newman Keuls and Student t tests, and the nonparametric ones by the Friedman and Mann Whitney test, with a significance level of 0.05. There were no significant differences between the groups and moments in clinical variables. Nevertheless, the SSH group presented a significant elevation of SBP and HR reduction at T72. Hematocrit and hemoglobin concentration decreased in both groups over time. Total leukocyte and monocyte counts showed a significant elevation in the SSH group, however the leukocytes were within the normal range at T72. There were no significant differences in the segmental neutrophils, but a 9.5-fold increase in T72 compared to T24 (P=0.09) in the SSH group was observed, whereas this increase was only 2.5-fold in the CON group (P=0.30). A decrease in platelet counts and globulin concentration was observed in the CON group, while these variables remained stable in the SSH group. In conclusion, serial administration of 7.5% SSH is promising in the therapy of dogs with acute hemorrhagic diarrhea syndrome, since it assists in the stabilization of leukocytes, platelets and globulins in dogs with severe sepsis due to this syndrome.(AU)

Avaliações macroscópica e histológica do reparo da cartilagem articular equina tratada com microperfurações do osso subcondral associadas ou não à injeção intra-articular de cartogenina / Macroscopic and histological evaluations of equine joint cartilage repair treated with microperforation of the subchondral bone associated or not with intra-articular kartogenin

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.

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.

Histologic and inflammatory lamellar changes in horses with oligofructose-induced laminitis treated with a CXCR1/2 antagonist / Alterações histológicas e inflamatórias no tecido laminar de equinos submetidos ao modelo de laminite por oligofrutose e tratados com um antagonista para CXCR1/2

With the hypothesis that blocking chemokine signaling can ameliorate acute laminitis, the aim was to evaluate the therapeutic effect of intravenous DF1681B, a selective antagonist for CXCR1 and CXCR2 (chemokine receptors), in an oligofructose equine laminitis model. To twelve mixed breed clinically healthy hoses with no previous history of hoof-related lameness was administered oligofructose (10g/kg given by nasogastric tube) and divided into two groups: treated (intravenous DF1681B at 30mg/kg 6, 12, 18, and 24h after oligofructose) and non-treated groups. Laminar biopsies were performed before and 12, 36, and 72h after administering oligofructose. Samples were stained with periodic acid-Schiff (PAS) and scored from 0 to 6 according to epidermal cell and basal membrane changes. The IL-1β, IL-6, and CXCL1 RNA expressions were determined by RT-PCR. Parametric and non-parametric tests were used to compare times within each group (P<0.05). The PAS grades and IL-1β and IL-6 RNA expression increased in the non-treated group, but remained constant in the treated horses. In conclusion, DF1681B therapy reduced laminar inflammation and epidermal deterioration in treated horses. CXCR1/2 blockage should be considered therapeutically for equine acute laminitis.

A expressão de quimiocinas e a infiltração de leucócitos no tecido laminar são característicos de laminite aguda de equinos. O presente estudo avaliou o efeito terapêutico da administração intravenosa de DF1681B , um antagonista seletivo para CXCR1 e CXCR2 (receptores de quimiocinas), em um modelo de laminite equina por oligofrutose. Utilizaram-se doze cavalos sem raça definida, compreendendo quatro machos e oito fêmeas não gestantes, com idade (média ±SD) 7±3,5 anos, pesando 305±35kg e com uma pontuação média de condição corporal de 5±1/9. Os indivíduos elegíveis eram clinicamente saudáveis, sem história prévia de claudicação relacionados ao casco. Após administração de oligofrutose (10g/kg por sonda nasogástrica), os animais foram divididos em dois grupos: tratado (30mg/kg de DF1681B intravenosa, 6, 12, 18 e 24h após a oligofrutose) e não tratado, que recebeu placebo. Biópsias laminares foram realizadas antes e 12, 36 e 72h após a administração de oligofrutose. As amostras foram coradas com ácido periódico de Schiff (PAS) e classificadas de 0-6 de acordo com alterações nas células epidérmicas e na membrana basal. Também determinaram-se as expressões gênicas de IL-1β, CXCL1 e IL-6 por RT-PCR. Testes paramétricos e não paramétricos foram utilizados para comparar os momentos em cada grupo (P<0,05). Estatisticamente, os graus PAS e as expressões de IL-1β e IL-6 se elevaram após a indução no grupo não tratado, mas se mantiveram constantes nos cavalos tratados. Em conclusão, a terapia por DF1681B reduziu a inflamação laminar e a deterioração epidérmica em equinos submetidos ao modelo de intoxicação por oligofructose. O bloqueio de receptores CXCR1/2 deve ser considerado como uma opção terapêutica para prevenção da laminite aguda de equinos.

Dispositivo fotobiomodulador para prevenção e tratamento de hiperqueratose de teto em vacas leiteiras / Photobiomodulation device for prevention and treatment of teat hyperkeratosis in dairy cows

As mastites estão entre as principais causas de prejuízo para produtores de leite. Em casos graves de hiperqueratose, o canal do teto pode se tornar uma barreira mais fácil para que as bactérias penetrem na glândula mamária. Os objetivos deste estudo foram avaliar um dispositivo fotobiomodulador de LED para tratamento e prevenção de hiperqueratose de teto e prevenção da mastite subclínica em um rebanho de leite com alta prevalência de hiperqueratose (35,3 por cento de casos graves). Foram utilizadas 60 primíparas para o experimento de prevenção e 30 vacas com hiperqueratose para o experimento terapêutico. Em ambos os experimentos, metade dos animais foram tratados com o dispositivo fotobiomodulador três vezes por semana, durante 6 semanas. Os outros animais foram os controles. Imagens fotográficas digitalizadas foram realizadas na avaliação inicial e, semanalmente, por 6 semanas consecutivas. Nas primíparas, novas avaliações foram realizadas entre 6 e 7 meses de lactação. Para avaliação da mastite subclínica, contagem de células somáticas (CCS) foram feitas mensalmente. No experimento preventivo, o diâmetro externo das lesões permaneceu constante nos tetos do grupo tratado, enquanto houve aumento no grupo controle. No experimento terapêutico não foram observadas diferenças estatísticas entre as variáveis de hiperqueratose. Contudo, o grupo tratado apresentou menor incidência de mastites subclínicas (CCS < 250 células/mL) por lactação do que o grupo controle (P<0,05). Em conclusão, o tratamento não foi efetivo em prevenir o desenvolvimento ou reduzir lesões instaladas de hiperqueratose de teto. Contudo, o uso protótipo se mostrou útil e promissor como adjuvante na prevenção do aumento de tamanho das lesões de hiperqueratose de teto em primíparas e como forma de reduzir incidência de mastite subclínicas em vacas leiteiras já acometidas.

Mastitis consistis one of the main problems of milk production, mainly due to the production losses and the rising cost of milk. In case of severe hyperkeratosis, the teat canal can become an easier barrier for the bacteria to penetrate. The objeSctive of this study was to assess a phototherapy device construct with LED light for prevention and treatment of teat hyperkeratosis in a dairy cattle herd with high prevalence (35.3 percent of severe cases). 60 primiparous cows were used in the preventive experiment and 30 cows with hyperkeratosis were used in the therapeutic experiment. In both experiments, half of the cows started to be treated in early lactation using the phototherapy device three times per week for 6 weeks. The other cows were the controls. Hyperkeratosis was assessed by scoring and by morphometric analyses of teat images that were taken at baseline and then weekly for 6 consecutive weeks. In the preventive experiment, more images were taken later, between 6 and 7 months of the first lactation. Somatic cell counts (SCC) were performed monthly. In the preventive experiment, the outer diameter of the teat lesions remained constant in the treated group, whereas cows of the control group showed a significant increase at the end of lactation. In the therapeutic groups, no statistical differences for teat hyperkeratosis variables were seen between groups. However, the incidence of subclinical mastitis (SCC > 250 cells/mL) during lactation was lower in the treated group (P<0.05). In conclusion the phototherapy protocol did not prevent the development in primiparous or ameliorate previous hyperkeratosis lesions in cows. However, the prototype was considered useful as an adjunct in preventing the increase in the size of teat hyperkeratosis lesions and also as a way to reduce subclinical mastitis incidence in affected dairy cows.

Avaliação clínica e hematológica de equinos submetidos ao modelo de laminite por oligofructose, tratados ou não com um agente antagonista de receptores CXCR1/2 / Clinical and hematological evaluation of horses subjected to oligofructose-induced laminitis treated or not with a CXCR1/2 antagonist

O recrutamento de leucócitos aos tecidos é uma parte essencial da resposta imune inata e esse processo de forma desregulada pode resultar em lesões aos tecidos. Assim, a infiltração de leucócitos tem sido implicada na patogênese de laminite aguda em equinos. Os objetivos dessa pesquisa foram verificar a ação da ICXCR1/2 sobre os sinais clínicos e parâmetros hematológicos de cavalos com laminite induzida por oligofrutose. Doze equinos receberam oligofrutose (10g/kg de peso vivo PO) no tempo 0 e foram divididos em 2 grupos: tratados (30mg/kg p.v. ICXCR1/2 IV, nos tempos 6, 12, 18 e 24 h) e não tratados. As frequências cardíaca e respiratória, temperatura retal, coloração de membranas mucosas, presença e intensidade de pulso digital, sensibilidade ao exame com pinça de casco e grau de claudicação segundo Obel, bem como parâmetros hematológicos e bioquímicos (hemograma e as concentrações sanguíneas de glicose, uréia, creatinina, ALT, AST, FA, GGT, bilirrubina total e proteína total) foram aferidos nos tempos 0, 6, 12, 18, 24, 36, 48, 60 e 72 horas . O modelo usando oligofructose foi adequado para induzir sinais de laminite e de sinais de endotoxemia, como diarreia, febre e leucocitose em cavalos sem raça definida de origem nacional. Também, não foram observadas quaisquer reações adversas clínicas ou hematológicas relacionadas ao uso intravenoso do antagonista de CXCR1/2, contudo essa substância, quando administrada na dose de 30mg/kg de peso vivo, 4 vezes ao dia, por 4 aplicações, não foi capaz de prevenir os sinais clínicos e as alterações hematológicas causadas pela administração de oligofructose nos equinos deste estudo.

Leucocytes recruitment to tissues is an essential part of the innate immune response and an unregulated process can result in tissue damage. Thus, leucocytes infiltration has been implicated in the pathogenesis of acute laminitis. The objectives of this stud were to determine the effect of an antagonist for CXCR1/2, a chemokine receptor for neutrophils attraction on clinical signs and hematological parameters in horses given oligofructose to induce laminitis. Twelve horses were given oligofructose (10g/kg bw PO) in time 0 and divided into two groups: one treated (30mg/kg bw. ICXCR1/2 IV, times 6, 12, 18 e 24 h) and the other not treated. Cardiac and respiratory frequency, rectal temperature, mucous membrane colour, digital pulse, hoof sensitivity and Obel's grade of lameness were recorded. Values for RBC, WBC and blood glucose, BUN, creatinin, ALT, AST, alkaline phosphatase, GGT, total bilirubin and serum protein concentrations were measured on times 0, 6, 12, 18, 24, 36, 48, 60 e 72 h. All the horses given oligofructose developed signs of endotoxemia like diarrhea, fever and leukocytosis and laminitis. Also, CXCR1/2 antagonist treatment did not cause any adverse effects. However, this substance when injected intravenously (30mg/kg) 6/6 hours in 4 applications, did not ameliorate clinical and hematological signs of endotoxemia.