The neuropathological landscape of small vessel disease and Lewy pathology in a cohort of Hispanic and non-Hispanic White decedents with Alzheimer disease.

Cerebrovascular and α-synuclein pathologies are frequently observed alongside Alzheimer disease (AD). The heterogeneity of AD necessitates comprehensive approaches to postmortem studies, including the representation of historically underrepresented ethnic groups. In this cohort study, we evaluated small vessel disease pathologies and α-synuclein deposits among Hispanic decedents (HD, n = 92) and non-Hispanic White decedents (NHWD, n = 184) from three Alzheimer's Disease Research Centers: Columbia University, University of California San Diego, and University of California Davis. The study included cases with a pathological diagnosis of Intermediate/High AD based on the National Institute on Aging- Alzheimer's Association (NIA-AA) and/or NIA-Reagan criteria. A 2:1 random comparison sample of NHWD was frequency-balanced and matched with HD by age and sex. An expert blinded to demographics and center origin evaluated arteriolosclerosis, cerebral amyloid angiopathy (CAA), and Lewy bodies/Lewy neurites (LBs/LNs) with a semi-quantitative approach using established criteria. There were many similarities and a few differences among groups. HD showed more severe Vonsattel grading of CAA in the cerebellum (p = 0.04), higher CAA density in the posterior hippocampus and cerebellum (ps = 0.01), and increased LBs/LNs density in the frontal (p = 0.01) and temporal cortices (p = 0.03), as determined by Wilcoxon's test. Ordinal logistic regression adjusting for age, sex, and center confirmed these findings except for LBs/LNs in the temporal cortex. Results indicate HD with AD exhibit greater CAA and α-synuclein burdens in select neuroanatomic regions when compared to age- and sex-matched NHWD with AD. These findings aid in the generalizability of concurrent arteriolosclerosis, CAA, and LBs/LNs topography and severity within the setting of pathologically confirmed AD, particularly in persons of Hispanic descent, showing many similarities and a few differences to those of NHW descent and providing insights into precision medicine approaches.

The neuropathological landscape of Hispanic and non-Hispanic White decedents with Alzheimer disease.

Despite the increasing demographic diversity of the United States' aging population, there remain significant gaps in post-mortem research investigating the ethnoracial heterogeneity in the neuropathological landscape of Alzheimer Disease (AD). Most autopsy-based studies have focused on cohorts of non-Hispanic White decedents (NHWD), with few studies including Hispanic decedents (HD). We aimed to characterize the neuropathologic landscape of AD in NHWD (n = 185) and HD (n = 92) evaluated in research programs across three institutions: University of California San Diego, University of California Davis, and Columbia University. Only persons with a neuropathologic diagnosis of intermediate/high AD determined by NIA Reagan and/or NIA-AA criteria were included. A frequency-balanced random sample without replacement was drawn from the NHWD group using a 2:1 age and sex matching scheme with HD. Four brain areas were evaluated: posterior hippocampus, frontal, temporal, and parietal cortices. Sections were stained with antibodies against Aß (4G8) and phosphorylated tau (AT8). We compared the distribution and semi-quantitative densities for neurofibrillary tangles (NFTs), neuropil threads, core, diffuse, and neuritic plaques. All evaluations were conducted by an expert blinded to demographics and group status. Wilcoxon's two-sample test revealed higher levels of neuritic plaques in the frontal cortex (p = 0.02) and neuropil threads (p = 0.02) in HD, and higher levels of cored plaques in the temporal cortex in NHWD (p = 0.02). Results from ordinal logistic regression controlling for age, sex, and site of origin were similar. In other evaluated brain regions, semi-quantitative scores of plaques, tangles, and threads did not differ statistically between groups. Our results demonstrate HD may be disproportionately burdened by AD-related pathologies in select anatomic regions, particularly tau deposits. Further research is warranted to understand the contributions of demographic, genetic, and environmental factors to heterogeneous pathological presentations.

Red blood cell distribution width to platelet ratio in neonatal foals with sepsis.

BACKGROUND: Rapid and accurate markers to aid diagnosis of sepsis are needed in neonatal foals. The CBC variable red blood cell distribution width (RDW) to platelet ratio (RPR) is associated with inflammatory response and linked to poor outcomes of sepsis in human patients. HYPOTHESIS: Explore the correlation of RPR with sepsis in neonatal foals and evaluate RPR predictive and prognostic value. ANIMALS: Three hundred seventeen hospitalized neonatal foals ≤7 days of age that had a CBC and physical exam performed at admission between 2012 and 2021. METHODS: Retrospective case-control study. Clinical records were used to calculate sepsis scores and define groups. Red blood cell distribution width to platelet ratio was calculated and compared between groups (septic vs nonseptic) based on Kruskal-Wallis and Wilcoxon signed-rank tests. A multivariate logistic regression model to predict sepsis was created. The cutoff for RPR was obtained based on the maximal Youden Index. The Kaplan-Meier method and the log-rank test were used to estimate survival curves and compare survival rates based on RPR. RESULTS: Red blood cell distribution width to platelet ratio was significantly higher in septic foals (Median = 0.099, confidence interval [CI] [0.093; 0.108]) than in sick nonseptic (0.085, CI [0.083; 0.089]) and healthy foals (0.081, CI [0.077; 0.086]; P < .0001). Red blood cell distribution width to platelet ratio was able to predict sepsis with high accuracy (AUC = 82.1%). The optimal RPR cutoff for sepsis was 0.09. CONCLUSIONS AND CLINICAL IMPORTANCE: Red blood cell distribution width to platelet ratio calculation is practical, inexpensive, and based on CBC-derived data. Calculation of RPR along with CBC can aid in the diagnosis of sepsis and estimation of outcome.

Effect of time and autologous serum addition on the analysis of cerebrospinal fluid in horses.

BACKGROUND: Cerebrospinal fluid (CSF) is highly labile and delayed processing might alter results of analysis. HYPOTHESIS/OBJECTIVES: To determine the effects of time and addition of autologous serum on cytological evaluation of CSF. ANIMALS: Ten client-owned adult horses requiring euthanasia. METHODS: Prospective study. Serum and CSF were collected from each horse before and within 10 minutes after euthanasia. CSF samples were divided into 15 aliquots (2 mL each); 1 aliquot was submitted for routine CSF analysis within 60 minutes of collection. Four drops of autologous serum were added to 7 of the aliquots, and stored at 4°C (serum group); the remaining 7 samples were stored unaltered at 4°C (control group). Total nucleated cell count (TNCC) and cell morphology score were done at T4, T8, T12, T24, T48, T72, and T96 hours after collection. Protein concentration was measured in the control group at T0 and T96 hours. RESULTS: The cell morphology scores were significantly different in the control group at T48 (median 2, range 0-4), T72 (2, 0-4), and T96 (3, 0-4) in comparison to T0 (1). No change was observed in the serum group. TNCC remained stable over time in both groups. No statistically significant difference in CSF protein concentration was found between T0 and T96. CONCLUSIONS AND CLINICAL IMPORTANCE: The addition of autologous serum to an aliquot of CSF sample before shipping improves the preservation of cell morphology up to 96 hours after collection.

The status of digital pathology and associated infrastructure within Alzheimer's Disease Centers.

Digital pathology (DP) has transformative potential, especially for Alzheimer disease and related disorders. However, infrastructure barriers may limit adoption. To provide benchmarks and insights into implementation barriers, a survey was conducted in 2019 within National Institutes of Health's Alzheimer's Disease Centers (ADCs). Questions covered infrastructure, funding sources, and data management related to digital pathology. Of the 35 ADCs to which the survey was sent, 33 responded. Most respondents (81%) stated that their ADC had digital slide scanner access, with the most frequent brand being Aperio/Leica (62.9%). Approximately a third of respondents stated there were fees to utilize the scanner. For DP and machine learning (ML) resources, 41% of respondents stated none was supported by their ADC. For scanner purchasing and operations, 50% of respondents stated they received institutional support. Some were unsure of the file size of scanned digital images (37%) and total amount of storage space files occupied (50%). Most (76%) were aware of other departments at their institution working with ML; a similar (76%) percentage were unaware of multiuniversity or industry partnerships. These results demonstrate many ADCs have access to a digital slide scanner; additional investigations are needed to further understand hurdles to implement DP and ML workflows.

Red cell distribution width values and red cell distribution width-to-platelet ratio in Thoroughbred foals in the first 24 hours of life.

OBJECTIVES: To report red cell distribution width (RDW) values, to calculate RDW-to-platelet ratio (RPR), and to investigate a possible correlation of RDW and RPR index values in neonatal foals classified as healthy or at risk based on clinical information from a population of foals up to 24 hours of life. DESIGN: Retrospective study conducted from records and CBCs of foals born between June and November from 2018 to 2020 foaling seasons. SETTING: Breeding farm. ANIMALS: Three hundred and nine neonatal full-term Thoroughbred foals. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Foals were evaluated by a veterinarian within 15 minutes after birth, and a blood sample was collected within 24 hours of life. Based on clinical information, 88 of 309 foals (28.4%) were considered at risk of perinatal disease, and 201 were healthy. Mean gestational age for the foals was 346.3 ± 9.7 days. RDW values did not differ between groups. Gestational length demonstrated to have a negative correlation with RDW (r = -0.156, P = 0.005) and mean corpuscular volume (r = -0.135, P = 0.01), indicating a link of these variables to foal maturity. RPR index was higher for at-risk (0.073 ± 0.018) than for healthy foals (0.068 ± 0.014, P = 0.01). CONCLUSION: RPR might be a promising early indicator of disease for the field triage of neonatal foals.

Prevalence of Genetic Mutations in Horses With Muscle Disease From a Neuromuscular Disease Laboratory.

Deleterious genetic variants are an important cause of skeletal muscle disease. Immunohistochemical evaluation of muscle biopsies is standard for the diagnosis of muscle disorders. The prevalence of alleles causing hyperkalemic periodic paralysis (HYPP), malignant hyperthermia (MH), polysaccharide storage myopathy 1 (PSSM1), glycogen branching enzyme deficiency (GBED), myotonia congenita (MC), and myosin heavy chain myopathy (MYHM) in horses with muscle disease is unknown. Archived slides processed for immunohistochemical analysis from 296 horses with muscle disease were reviewed blinded and clinical information obtained. DNA isolated from stored muscle samples from these horses were genotyped for disease variants. Histological findings were classified as myopathic in 192, neurogenic in 41, and normal in 63 horses. A third of the population had alleles that explained disease which constituted 45% of the horses with confirmed histological myopathic process. Four of six muscle disease alleles were identified only in Quarter horse breeds. The allele causing PSSM1 was detected in other breeds, and MC was not detected in these samples. The My allele, associated with susceptibility for MYHM, was the most common (62%) with homozygotes (16/27) presenting a more severe phenotype compared to heterozygotes (6/33). All cases with the MH allele were fatal upon triggering by anesthesia, stress or concurrent myopathy. Both, muscle histological and genetic analyses are essential in the investigation of muscle disease, since 10% of the horses with muscle disease and normal histology had a muscle disease causing genetic variant, and 63% of histologically confirmed muscle with alterations had no known genetic variants.

Is the modified shuttle test a maximal effort test in children and adolescents with asthma?

PURPOSE: Whether the modified shuttle test (MST) achieves maximal effort in children and adolescents with asthma is unclear. The aim was to compare the physiological responses of MST to the cardiopulmonary exercise test (CPET) in pediatric patients with asthma, to observe its convergent validity. PATIENTS AND METHODS: A cross-sectional study with volunteers with asthma (6-17 years of age) under regular treatment. The MST is an external-paced test, and the participants were allowed to walk/run. CPET was performed on a cycle ergometer to compare with MST. Gas exchange (VO2 , VCO2 , and VE) and heart rate (HR) were the outcomes and were continuously assessed in both tests. RESULTS: Forty-seven volunteers were included, normal lung function expiratory forced volume at 1st second/forced vital capacity (FEV1 /FVC) 88.6 (7.7). VO2peak was higher at MST (2.0 ± 0.6 L/min) compared to CPET (1.6 ± 0.5 L/min), p < 0.001. Similar results was observed to VE at MST (50 ± 16 L/min) versus VE at CPET (40 ± 13 L/min), and to VCO2 at MST (2.1 ± 0.8 L/min) versus VCO2 at CPET (1.7 ± 0.6 L/min), p < 0.001. HR was also higher at MST (94 ± 6%pred) versus CPET (87 ± 8%pred), p = 0.002. VO2peak in MST correlated to the CPET (r = 0.78, p < 0.001). The ICC of VO2peak between tests was 0.73 (0.06-0.89), p < 0.001, and VO2peak Bland-Altman analysis showed a bias of 0.46 L/min. CONCLUSION: The MST showed a maximal physiologic response in children and adolescents with asthma. It is a valid test and can be used as an alternative to evaluating exercise capacity.

Gentamicin-induced sensorineural auditory loss in healthy adult horses.

BACKGROUND: Irreversible sensorineural auditory loss has been reported in humans treated with aminoglycosides but not in horses. OBJECTIVE: Investigate if auditory loss occurs in horses treated using the recommended IV daily dosage of gentamicin for 7 consecutive days. ANIMALS: Ten healthy adult horses (7-15 years; females and males, 5 each). METHODS: Prospective study. Physical and neurological examinations and renal function tests were performed. Gentamicin sulfate was administered at a dosage of 6.6 mg/kg via the jugular vein on alternating sides for 7 days. Gentamicin peak and trough concentrations were measured. Horses were sedated using detomidine hydrochloride IV to perform brainstem auditory evoked responses (BAER) before the first dose, immediately after the last dose, and 30 days after the last dose. Peaks latencies, amplitudes, and amplitude ratios were recorded. Data from the second and last BAER were compared to results at baseline. Bone conduction was performed to rule out conduction disorders. RESULTS: Seven horses had auditory loss: complete bilateral (N = 1), complete unilateral (N = 2), and partial unilateral (N = 4). Based on physical examination and BAER results, sensorineural auditory loss was suspected. Absent bone conduction ruled out a conduction disorder and further supported sensorineural auditory loss in horses with completely absent BAER. Auditory dysfunction was reversible in 4 of 7 horses. CONCLUSIONS AND CLINICAL IMPORTANCE: Gentamicin at recommended doses may cause sensorineural auditory loss in horses that might be irreversible. Follow-up studies are needed to investigate if other dosing protocols present a similar risk.

Occurrence of Gasterophilus spp. in weanling foals in southern Brazil

The occurrence of gastrointestinal myiasis caused by Gasterophilus spp. larvae (Diptera: Oestridae) in adult horses has been widely characterized, however data on natural infestation in young foals have been lacking. This observation may be related to the absence of conclusive diagnosis in these individuals, most likely due to logistical or financial constraints. Gastric ulceration is a problem and a significant cause of morbidity in foals, particularly during the weaning stage; therefore, gasterophilosis should be included in the differential diagnosis. The primary purpose of this study was to determine the prevalence of gasterophilosis in 4- to 6-month-old weanling foals. Seventy-one healthy weanling foals were enrolled in the study. Physical assessment blood sampling and was completed in all foals before the commencement of the experiment. Gastroscopy examinations were performed under sedation (Detomidine 0.01 - 0.02 mg/kg) with a flexible endoscope inserted through nasogastric via. The lumen of the stomach was examined in order to search for botflies' larvae. Following gastroscopy, foals were classified into 2 groups based on the presence of Gasterophilus spp. larvae in their stomachs: 1) Infected and 2) Not Infected. Infected foals received a single dose of commercial trichlorfon and albendazole equine oral gel and were stalled for 24 h. The passed feces were thoroughly examined, searching for elimination of larvae. A total of 64% of the foals (n = 45/71) harbored Gasterophilus spp. larvae in the stomach. Mild hyperemia in the gastric mucosa was observed in the attachment sites of the parasites. Physical assessment and hematological parameters' data were analyzed with Shapiro-Wilk normality test. Comparison between groups for clinical signs, hematological parameters and Gasterophilus spp. infection rates were evaluated using the Kruskal-Wallis test or Student's t-test. Statistical significance was set at P < 0.05. There were no statistically significant variations in physical and hematological parameters between foals that were affected and those that were not infected. The larvae found in the feces were subjected to morphological examination, which confirmed the diagnosis of Gasterophilus intestinalis. No systemic clinical indications compatible with Gasterophilus spp. infestation were seen, as described in previous studies of horses infected with the parasite. No botfly eggs were observed in the hair of evaluated foals. During gastroscopy, mild hyperemic lesions in the gastric mucosa were observed in the larvae fixation sites. Although no changes in clinical or hematological parameters were noted, the confirmation of parasite presence is a cause for concern due to horses' tolerance for low infestation levels and poor diagnosis. Additionally, the presence of this myiasis in foals may be a significant stressor during the weaning period and should be included in the differential diagnosis of recurring abdominal pain. Furthermore, infected foals might be a reservoir for the parasite and, contribute to the elimination and spread of the larvae in the environment. Thus, inclusion of young horses in deworming protocols targeted to botfly larvae is needed. This is the first report of Gasterophilus intestinalis myiasis in foals in Brazil. Further research is necessary to fully understand the epidemiology and prevalence of this condition in young horses in Brazil, based on the findings of this study.(AU)

Patients with asthma have reduced functional capacity and sedentary behavior / Pacientes com asma apresentam redução da capacidade funcional e comportamento sedentário

Abstract Objective The modified shuttle test is a field test that avoids the ceiling effect, and there are no reports of a multidimensional assessment concerning physical activity in asthmatic patients. Thus, the aim was to evaluate functional capacity by MST, additionally to perform a multidimensional assessment as physical activity in daily life, muscle strength, and cytokine levels in children and adolescents with asthma, and to correlate these variables. Method This cross-sectional study included volunteers aged between 6 and 18 years who were divided into two groups: asthma group (n = 43) that received regular treatment and control group (n = 24). Functional capacity was evaluated by distance walked during the MST; physical activity in daily life was evaluated using an accelerometer by the number of steps. Quadriceps femoris strength was evaluated by load cell. Results Distance walked was lower for the asthma group (790 m [222 m]) when compared with the control group (950 m [240 m]; p = 0.007); however, the number of steps was similar between the two groups (asthma group: 7743 [3075]; control group: 7181 [3040]; p = 0.41), and both groups were classified as sedentary behavior. There was no difference in muscle strength. Tumor necrosis factor-α differed, but interleukin levels were similar between groups. Quadriceps strength was correlated to distance walked (r = 0.62; p < 0.001) and tumor necrosis factor-α to the number of steps taken (r = −0.54, p = 0.005). Conclusion Children and adolescents undergoing regular asthma treatment showed reduced functional capacity and sedentary behavior. The lower the quadriceps strength, the shorter the distance walked; the higher the tumor necrosis factor-α levels, the lower their daily physical activity levels.

Resumo Objetivo O Teste Shuttle Modificado é um teste clínico de campo que evita o efeito-teto e não existem relatos de avaliação multidimensional com relação à atividade física em pacientes com asma. Assim, o objetivo era avaliar a capacidade funcional, a atividade física na vida cotidiana, a força muscular e os níveis de citocina em crianças e adolescentes com asma, a fim de correlacionar essas variáveis. Método Este estudo transversal incluiu voluntários entre seis e 18 anos, os quais foram divididos em dois grupos: o grupo com asma (n = 43), que recebeu tratamento regular, e o grupo de controle (n = 24). A capacidade funcional foi avaliada pela distância percorrida durante o Teste Shuttle Modificado, ao passo que a atividade física na vida cotidiana foi avaliada utilizando um acelerômetro pelo número de passos. A força muscular do quadríceps femoral foi avaliada por uma célula de carga. Resultados A distância percorrida foi menor no grupo com asma (790 m [222 m]) em comparação com o grupo de controle (950 m [240 m]; p = 0,007), contudo o número de passos foi semelhante nos dois grupos (grupo com asma: 7.743 [3.075]; grupo de controle: 7.181 [3.040]; p = 0,41) e ambos os grupos foram classificados como sedentários. Não houve diferença na avaliação da força muscular. O fator de necrose tumoral-α apresentou divergências, porém os níveis de interleucina foram semelhantes entre os grupos. A força muscular do quadríceps foi correlacionada com a distância percorrida (r: 0,62; p < 0,001) e o fator de necrose tumoral-α, ao número de passos dados (r = −0,54, p = 0,005). Conclusão Crianças e adolescentes que recebem tratamento regular de asma apresentaram redução da capacidade funcional e comportamento sedentário. Quanto menor a força muscular do quadríceps, menor a distância percorrida; quanto maiores os níveis de fator de necrose tumoral-α, menores seus níveis diários de atividade física.

Patients with asthma have reduced functional capacity and sedentary behavior.

OBJECTIVE: The modified shuttle test is a field test that avoids the ceiling effect, and there are no reports of a multidimensional assessment concerning physical activity in asthmatic patients. Thus, the aim was to evaluate functional capacity by MST, additionally to perform a multidimensional assessment as physical activity in daily life, muscle strength, and cytokine levels in children and adolescents with asthma, and to correlate these variables. METHOD: This cross-sectional study included volunteers aged between 6 and 18 years who were divided into two groups: asthma group (n=43) that received regular treatment and control group (n=24). Functional capacity was evaluated by distance walked during the MST; physical activity in daily life was evaluated using an accelerometer by the number of steps. Quadriceps femoris strength was evaluated by load cell. RESULTS: Distance walked was lower for the asthma group (790m [222m]) when compared with the control group (950m [240m]; p=0.007); however, the number of steps was similar between the two groups (asthma group: 7743 [3075]; control group: 7181 [3040]; p=0.41), and both groups were classified as sedentary behavior. There was no difference in muscle strength. Tumor necrosis factor-α differed, but interleukin levels were similar between groups. Quadriceps strength was correlated to distance walked (r=0.62; p<0.001) and tumor necrosis factor-α to the number of steps taken (r=-0.54, p=0.005). CONCLUSION: Children and adolescents undergoing regular asthma treatment showed reduced functional capacity and sedentary behavior. The lower the quadriceps strength, the shorter the distance walked; the higher the tumor necrosis factor-α levels, the lower their daily physical activity levels.

Validation of the Modified Shuttle Test to Predict Peak Oxygen Uptake in Youth Asthma Patients Under Regular Treatment.

Background: Oxygen uptake (VO2) evaluations by cardiopulmonary exercise test is expensive and time-consuming. Estimating VO2 based on a field test would be an alternative. Objective: To develop and validate an equation to predict VO2peak based on the modified shuttle test (MST). Methods: Cross sectional study, with 97 children and adolescents with asthma. Participants were divided in two groups: the equation group (EG), to construct the equation model of VO2peak, and the cross-validation group (VG). Each subject performed the MST twice using a portable gas analyzer. The peak VO2peak during MST was used in the equation model. The patients' height, weight, gender, and distance walked (DW) during MST were tested as independent variables. Results: The final model [-0.457 + (gender × 0.139) + (weight × 0.025) + (DW × 0.002)] explained 87% of VO2peak variation. The VO2peak predicted was similar to VO2peak measured by gas analyzer (1.9 ± 0.5 L/min and 2.0 ± 0.5 L/min, respectively) (p = 0.67), and presented significant ICC 0.91 (IC95% 0.77 to 0.96); p < 0.001. The Bland-Altman analysis showed low bias (-0.15 L/min) and limits of agreement (-0.65 to 0.35 L/min). There was no difference in DW between EG (760 ± 209 m) and VG (731 ± 180 m), p = 0.51. Conclusion: The developed equation adequately predicts VO2peak in pediatric patients with asthma.

Development of a weight-estimation model to use in pregnant criollo-type mares / Modelo para estimativa de peso em éguas gestantes mestiças crioulas

ABSTRACT: The aims of this study were: 1) to compare the tape weight and associated weight-estimation formula to evaluate weight gain in pregnant mares, and 2) to develop a mathematical model to estimate the weight of pregnant mares using body measurements. Thirty-four criollo-type mares were evaluated every two weeks during the middle and late pregnancy. The mares were weighed on a livestock scale, and we estimated body weight using tape weights and an associated body-weight estimation formula. Also, heart-girth circumference (heartgirth) and abdominal circumference were measured; the latter at the 12th intercostal space (12th ICS) and 18th rib (18th Rib), to use in a mathematical model to estimate the weight of pregnant mares. Observations were divided into three periods of pregnancy: 5th to 7 h month, 7th to 9 h month, and 9th to 11th month. Mares in late pregnancy showed an increase in actual weight and an increase in 12th ICS and 18th Rib measurements. Tape weight and body-weight estimation formula underestimated the weight of pregnant mares. However, the regression model using heart-girth circumference, 12th ICS, and 18th Rib measurements showed high correlation (r2 = 0.87, P<0.001) with actual weight. Finally, the alternative methods usually used in horses are not accurate to estimate body weight in pregnant mares. In conclusion, the regression model Y=-540.143 + (heartgirth x 3.068) + (12th ICS x 1.278) + (18th Rib x 0.944) can be used to estimate body weight in pregnant mares from the 5th to 11th months of pregnancy.

RESUMO: Este estudo teve como objetivos: 1) comparar a utilização dos métodos alternativos fita de pesagem e peso metabólico em éguas gestantes e; 2) desenvolver um modelo matemático para estimar o peso de éguas gestantes, baseado em medidas corporais. Trinta e quatro éguas foram avaliadas quinzenalmente durante o terço médio e final da gestação. Foi realizada a pesagem em balança comercial; a mensuração com a fita de peso para equinos; o cálculo do peso metabólico; as medidas de perímetro torácico (Ptorac); a mensuração abdominal no décimo segundo espaço intercostal (12EI) e na décima oitava costela (18Cost). As observações foram divididas em três períodos gestacionais: Período de 5 a 7 meses, Período de 7 a 9 meses e Período de 9 a 11 meses. As éguas demonstraram incremento no peso na balança e na mensuração abdominal no 12EI e 18Cost no terço final da gestação. A utilização da fita de pesagem e o cálculo de peso metabólico subestimaram o peso na balança em éguas gestantes. O modelo de regressão utilizando o Ptorac, 12EI e 18Cost apresentou alta correção (r2=0,87; P<0,001) com o peso na balança. Observou-se que os métodos alternativos de pesagem, usualmente utilizados, não apresentaram a mesma eficiência em éguas prenhes. Pode-se concluir que o modelo de regressão Y=-540,143+(Ptorac X 3,068) + (12EI X 1,278) + (18Cost X 0,944) pode ser utilizado para mensurar o peso em éguas gestantes a partir do 5º mês de gestação.