title: Histomorphometry of the placental vasculature and microcotyledons in Thoroughbred mares with chronic laminitis.
abstract: The objective of this study was to assess the placental vasculature and microcotyledons in pregnant mares with chronic laminitis. Twenty-six pregnant mares were enrolled in the study, 13 had chronic laminitis (Laminitis Group) and 13 were healthy mares (Healthy Group). Arterial systolic pressure and heart rate were measured in the last 30 days of gestation. After foaling, the fetal membranes were grossly evaluated and samples were harvested for histopathologic examination. All mares had digitalized images taken from chorioallantois for histomorphometry analyses (software-NIH ImageJ). Images were assessed for: (i) arterioles from the allantoic region: total and lumen vascular diameter and vascular wall thickness; (ii) microcotiledonary and capillary area/field. Mares in the Laminitis Group showed hypertension, shorter gestational length, lower placental weight and lower birthweight (p < 0.05) foal in comparison with mares in the Healthy Group. Laminitis mares had a reduction of vascular lumen diameters in the uterine body and pregnant horn (p < 0.05), vascular wall thickening in the pregnant horn (p < 0.05) and smaller capillary area/field in the microcotyledons of uterine body and pregnant horn (p < 0.05). In conclusion, pregnant mares with chronic laminitis presented signs of hypertension syndrome, and vascular abnormalitities in placental vessels such as reduction in the vascular lumen and capillary area in the microcotyledones, and thickening of the vascular wall. Foals born from mares with chronic laminitis showed lower birth weight and shorter gestation lengths.
authors.affiliation: Department of Veterinary Clinics, College of Veterinary, Federal University of Pelotas - UFPel, RS, Brazil.
authors.forename: Fernanda M
authors.initials: FM
authors.lastname: Pazinato
authors.affiliation: Department of Veterinary Clinics, College of Veterinary, Federal University of Pelotas - UFPel, RS, Brazil. Electronic address: curciobruna@hotmail.com.
authors.forename: Bruna da Rosa
authors.initials: BDR
authors.lastname: Curcio
authors.affiliation: Department of Animal Pathology, College of Veterinary, Federal University of Pelotas - UFPel, RS, Brazil.
authors.forename: Cristina G
authors.initials: CG
authors.lastname: Fernandes
authors.affiliation: Department of Veterinary Clinics, College of Veterinary, Federal University of Pelotas - UFPel, RS, Brazil.
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Santos
authors.affiliation: Department of Veterinary Clinics, College of Veterinary, Federal University of Pelotas - UFPel, RS, Brazil.
authors.forename: Lorena S
authors.initials: LS
authors.lastname: Feijó
authors.affiliation: Institute of Biological Sciences, Federal University of Rio Grande - FURG, RS, Brazil.
authors.forename: Antonio Sérgio
authors.initials: AS
authors.lastname: Varela
authors.affiliation: Department of Veterinary Clinics, College of Veterinary, Federal University of Pelotas - UFPel, RS, Brazil.
authors.forename: Carlos E W
authors.initials: CEW
authors.lastname: Nogueira
mesh_terms: D000818:Animals; D005260:Female; D005534:Foot Diseases / Q000150:complications / Q000662:veterinary*; D006724:Hoof and Claw / Q000473:pathology*; D006734:Horse Diseases / Q000473:pathology*; D006736:Horses / Q000196:embryology*; D010920:Placenta / Q000098:blood supply* / Q000473:pathology; D011247:Pregnancy
keywords: capillary area; equine obstetrics; foal; hypertension; placental pathology