High Seroprevalence of Lawsonia intracellularis in Thoroughbred Farms in Southern Brazil.

The aim of the present study was to carry out a serological survey to identify the seroprevalence of Lawsonia intracellularis in six Thoroughbred farms in the Southern region of the state of Rio Grande do Sul, Brazil. During 2019 and 2020, blood samples from 686 Thoroughbred horses were obtained from six different breeding farms. Horses were divided into groups according to age: (1) broodmares (>5 years), (2) two-year-old foals, (3) yearlings, and (4) 0-6 months-old foals. Blood samples were collected by venipuncture of the external jugular vein. The detection of antibodies (IgG) against L. intracellularis was performed by Immunoperoxidase Monolayer Assay. The detection of specific antibodies (IgG) against L. intracellularis in the evaluated population was 51%. The highest detection (86.8%) of IgG was in the broodmares category, while the lowest (5.2%) was in foals of 0-6 months of age. Regarding the farms, the Farm 1 had the highest (67.4%) prevalence of seropositivity against L. intracellularis, while Farm 4 had the lowest (30.6%). There was no record of clinical manifestation of Equine Proliferative Enteropathy in the sampled animals. The results of this study show the high seroprevalence of L. intracellularis in Thoroughbred farms in the Southern of Rio Grande do Sul, suggesting a large and continuous exposure to the agent.

Serum cortisol and thyroid hormone concentrations and survival in foals born from mares with experimentally induced ascending placentitis.

BACKGROUND: There are few publications on occurrence of nonthyroidal illness syndrome in foals and on the prognostic value of cortisol and thyroid hormone (TH) concentrations in newborn foals. OBJECTIVES: To determine serum cortisol and TH concentrations (total and free thyroxine: T4 and F T4 ; total and free triiodothyronine: T3 and F T3 ) in foals born from mares with placentitis, to determine their association with survival, and their use as prognostic markers. ANIMALS: A cohort of 29 newborn foals comprising 5 Control, 14 Low-risk, and 10 Sick foals were evaluated over the first week of life. METHODS: In this prospective study foals born to mares with experimentally-induced placentitis were assigned to Low-risk or Sick groups while foals born to control mares were classified as Control based on clinical findings. Foals were also classified as Term (n = 13), Dysmature (n = 7), or Premature (n = 9), and survival rate was recorded. Serum cortisol and TH hormone concentrations were measured at 0, 12, 24, 48, and 168 hours of life. RESULTS: Sick non-surviving foals had lower (P < .05) T3 : cortisol ratio at 12 (3.68 ± 1.06 versus 18.58 ± 2.78), 24 (5.47 ± 2.34 versus 23.40 ± 3.82), and 48 (10.47 ± 6.29 versus 26.6 ± 2.90) hours of life when compared to Sick surviving foals and lower (P < .05) T4 : cortisol ratio at 12 (75.12 ± 21.71 versus 414.47 ± 58.47) and 24 hours (127.83 ± 55.21 versus 430.87 ± 80.31) after birth than Sick surviving foals. CONCLUSION AND CLINICAL IMPORTANCE: Placental infections can impair fetal thyroid function. Low T3 : cortisol and T4 : cortisol ratios seem to be good prognostic markers in newborn foals.

Glucose and insulin curve in pregnant mares and its relationship with clinical and biometric features of newborn foals / Curvas de glicose e insulina em éguas gestantes e sua relação com as características clínicas e biométricas dos neonatos

The aim of the present study was to describe the dynamics of glucose and insulin curves in pregnant mares, and to evaluate the curves according to body condition score, identifying the presence of insulin resistance and correlating these values ​​with the weight, height and clinical changes of the neonates. For this, pregnant mares were evaluated and then grouped according to body condition score during the gestation length until lactation. GrM corresponds to mares with moderate body score (BCS 5-6); GrOv were mares with overweight body score (BCS 7) and GrOb were obese mares (BCS 8-9). A two-step oral sugar test (OST) was used to determine the data. Cortisol analysis was performed with 300-320 days of gestation, at foaling and after parturition. For evaluation of the neonate, a general clinical examination and, weight and height measurements were performed. The results showed hyperglycemia in response to OST with normal insulin values at foaling with a subsequent fall in both values at lactation disregarding group division. Baseline glucose was decreased in GrM compared to GrOv and GrOb with 70-100 days of gestation and with 130-160 days of gestation. With 270-300 days of gestation and post-partum GrOb had increased baseline glucose than GrM. After OST, glucose at foaling day in GrOb presented increased values than GrM. Baseline insulin values did not differ between groups. Post OST insulin levels were higher in GrOb than GrM and GrOv at parturition. No difference in cortisol between moments was identified. GrOb and GrOv maintained increased concentrations after foaling while GrM had a decrease. No correlation was found between maternal glucose and insulin values with foal weight and height, however, a lower ratio between neonatal weight and mare's weight in GrOb and GrOv was identified in relation to the GrM. At foaling, mares presented glucose dysregulation, with obese and overweight mares presenting a greater response to OST.(AU)

O objetivo do presente estudo foi descrever a dinâmica das curvas de glicose e insulina em éguas gestantes e avaliar as curvas de acordo com o escore de condição corporal, identificando a presença de resistência insulínica e correlacionando esses valores com o peso, altura e alterações clínicas dos neonatos. Para isso, as éguas prenhes foram avaliadas em conjunto e agrupadas de acordo com o escore de condição corporal durante a gestação até o pós-parto. GrM pertenciam éguas com escore corporal moderado (EC 5-6); GrOv, grupo de éguas com escore corporal acima do peso (EC 7) e GrOb, grupo de éguas obesas (EC 8-9). O teste de glicose oral em duas etapas (OST) foi usado para determinar os dados. A análise do cortisol também foi realizada nos 300-320 dias de gestação, no dia do parto e após o parto. Para avaliação do neonato, foram realizados exame clínico geral e medidas de peso e altura. Os resultados mostraram hiperglicemia em resposta ao OST com valores normais de insulina no momento parto, com uma queda subsequente em ambas as variáveis na lactação, desconsiderando a divisão do grupo. A glicemia basal diminuiu no GrM em comparação com GrOv e GrOb com 70-100 dias de gestação e com 130-160 dias de gestação. Com 270-300 dias de gestação e no pós-parto, o GrOb apresentou aumento na glicemia basal em relação ao GrM. Após OST, a glicose no dia do parto no GrOb apresentou valores aumentados em relação ao GrM. Os valores basais de insulina não diferiram entre os grupos. Após OST níveis de insulina foram maiores no GrOb do que GrM e GrOv no momento do parto. Não houve diferença nos valores de cortisol entre os momentos. O GrOb e GrOv mantiveram cortisol aumentado após o parto enquanto o GrM diminuiu. Não foi encontrada correlação entre os valores de glicemia e insulina materna com o peso e a altura do potro, entretanto, foi identificada uma relação menor entre o peso neonatal e o peso da égua no GrOb e GrOv em relação ao GrM. No parto, as éguas apresentaram desregulação da glicose, sendo que as éguas obesas e com sobrepeso apresentaram uma resposta maior ao OST.(AU)