Open AccessSerum cortisol and thyroid hormone concentrations and survival in foals born from mares with experimentally induced ascending placentitis
Author(s) -
Müller Vitória,
Toribio Ramiro E.,
Dembek Katarzyna,
Moraes Bruna S. S.,
Mousquer Mariana A.,
Curcio Bruna R.,
Nogueira Carlos E. W.
Publication year - 2020
Publication title -
journal of veterinary internal medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.356
H-Index - 103
eISSN - 1939-1676
pISSN - 0891-6640
DOI - 10.1111/jvim.15758
Subject(s) - medicine , triiodothyronine , hormone , horse , thyroid , prospective cohort study , hydrocortisone , endocrinology , gastroenterology , paleontology , biology
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: T 4 and F T 4 ; total and free triiodothyronine: T 3 and F T 3 ) 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) T 3 : 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) T 4 : 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 T 3 : cortisol and T 4 : cortisol ratios seem to be good prognostic markers in newborn foals.