title: Black walnut (Juglans nigra) toxicosis: a model for equine laminitis.
abstract: Twelve light horse geldings developed laminitis within 8 to 12 h of being dosed by nasogastric tube with an aqueous extract of black walnut (Juglans nigra). Four of the 12 horses developed the severe signs of grade 3 laminitis (lame at a walk, refused to lift feet). Laminitis was accompanied by mild depression and limb oedema. There was no evidence of shock or colic. The horses developed neutropenia by 4 h after dosing with the extract, which shifted to a relative neutrophilia by 8 to 12 h. Minimal increases in plasma epinephrine and cortisol concentrations were suggested in severely affected horses. Severe laminitis was characterized by necrosis of dermal tips of dorsal primary epidermal laminae. A proliferative epithelial response in these laminae was distinguished by numerous mitotic figures and clusters of epithelial cells. This evidence suggests that black walnut toxicosis is not only a consistent clinical model, but is also a reliable clinico-pathological and pathological model for study of the pathogenesis and treatment of laminitis.
authors.affiliation: Department of Veterinary Biosciences, College of Veterinary Medicine, University of Illinois, Urbana.
authors.forename: F D
authors.initials: FD
authors.lastname: Galey
authors.forename: H E
authors.initials: HE
authors.lastname: Whiteley
authors.forename: T E
authors.initials: TE
authors.lastname: Goetz
authors.forename: A R
authors.initials: AR
authors.lastname: Kuenstler
authors.forename: C A
authors.initials: CA
authors.lastname: Davis
authors.forename: V R
authors.initials: VR
authors.lastname: Beasley
mesh_terms: D000818:Animals; D001774:Blood Chemical Analysis / Q000662:veterinary; D004195:Disease Models, Animal; D005528:Foot / Q000473:pathology; D005552:Forelimb / Q000473:pathology; D006403:Hematologic Tests / Q000662:veterinary; D006734:Horse Diseases / Q000097:blood / Q000139:chemically induced* / Q000473:pathology; D006736:Horses; D007794:Lameness, Animal / Q000209:etiology; D009754:Nuts / Q000633:toxicity*; D010936:Plant Extracts / Q000633:toxicity*
chemical_list: D010936:Plant Extracts