Toxicon:X 5 (2020) 100024 Available online 23 January 2020 2590-1710/© 2020 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Short Communication Hemorrhagic diathesis in cattle due to consumption of Adiantopsis chlorophylla (Swartz) F� ee (Pteridaceae) Luiz Gustavo Schneider de Oliveira a , Fabiana Marques Boabaid b , Vaidotas Kisielius c , Lars Holm Rasmussen c , Florencia Buroni a, d , Martín Lucas a , Carlos Omar Schild a , Fabiana L� opez d , Mizael Machado a , Franklin Riet-Correa a, * a Instituto Nacional de Investigaci� on Agropecuaria (INIA), Plataforma de Investigaci� on en Salud Animal, Estaci� on Experimental INIA Tacuaremb� o, Tacuaremb� o, Uruguay b Polo de Desarrollo Universitario Del Instituto Superior de La Carne, Centro Universitario Regional (CENUR) Noreste, Universidad de La República, Tacuaremb� o, Uruguay c Department of Technology, University College Copenhagen, Copenhagen, Denmark d Divisi� on de Laboratorios Veterinarios “Miguel C. Rubino” Regional Norte, Ministerio de Ganadería Agricultura y Pesca (MGAP), Tacuaremb� o, Uruguay A R T I C L E INFO Keywords: Cattle diseases Fern toxicity Hematopoietic diseases Caudatoside ABSTRACT An outbreak of acute febrile syndrome associated with coagulopathy and severe pancytopenia occurred in cattle grazing in paddocks with high infestation by Adiantopsis chlorophylla. The administration of the plant to a calf reproduced the same signs and lesions seen in spontaneous cases. Similar syndromes are caused by ptaquiloside from bracken fern. Traces of the ptaquiloside-like molecule caudatoside were detected together with 0.03–0.24 mg/g of it’s degradation product pterosin A, in dry fronds of the plant. In conclusion, A. chlorophylla is a cause of hemorrhagic diathesis in cattle. Hemorrhagic diathesis is a disease of cattle resulting from bone marrow hypoplasia, frequently associated with acute poisoning by Pteridium spp. In many parts of the world (França et al., 2002; Tokarnia et al., 2012; Constable et al., 2017; Boabaid et al., 2018) and by Chei- lanthes sieberi in Australia (Clark and Dimmock, 1971). Besides the acute form, enzootic hematuria and upper alimentary tract carcinomas can result from long-term consumption of different ferns, such as the above-mentioned Pteridium spp. (D€ obereiner et al., 1967; Tokarnia et al., 1969; Carvalho et al., 2006; Souto et al., 2006; Lucena et al., 2011), Cheilanthes sieberi (McKenzie, 1978; Smith et al., 1989), Onychium con- tiguum (Dawra et al., 2001), Pteris defexa and Pteris plumula (Micheloud et al., 2017). The active principle responsible for both acute and chronic Pteridium spp. toxicity in ruminants is the norsesquiterpene compound ptaquiloside (Hirono et al., 1984; Yamada et al., 2007). Ptaquiloside and similar compounds from bracken and other ferns degrade naturally to pterosins. Pterosin’s are found naturally in old plant material, in artif- cially dried samples such as fern-based food products, and are e.g. also formed in rumen juice upon digestion of ptaquiloside (Caceres-Pena et al., 2012; Gil da Costa et al., 2012; Aranha et al., 2019). Other ptaquiloside-like molecules such as caudatoside, isoptaquiloside, pta- quiloside Z, among others, are found in different species of ferns, however their toxicity is still being studied (Castillo et al., 1997; Fletcher et al., 2011). Pteridium aquilinum poisoning was reported in Uruguay causing enzootic hematuria in cattle in 2010 (Dutra, 2010). Outbreaks of hemorrhagic diathesis took place in Uruguay in 2019; however, the ferns involved in these cases have not been identifed (Dutra, 2019). The aim of this study was to describe the occurrence of hemorrhagic diath- esis in cattle associated with consumption of Adiantopsis chlorophylla (Pteridaceae) in northern Uruguay. A silvopastoral farm located in the Department of Tacuaremb� o, in the north of Uruguay was visited to investigate an ongoing outbreak of cattle mortality during Spring 2018. Clinical inspection of the herd was done and historical data were obtained with the referring veterinarian. The herd was composed of 980 Braford, Hereford and mixed breed feeder steers (2-3 years-old), which were introduced in a forest of about 2,000ha of mature Eucalyptus grandis W. Hill and Pinus elliotti Engelm. trees in December 2017. The area was divided into paddocks of 200–300ha with a total of 100–180 cattle in each group. In addition, 30 heifers (2-3 years-old) were kept in a paddock with a natural pasture free of Eucalyptus and Pinus trees. None of the heifers were affected during the period. General sanitary measures included multivalent clostridial vaccination, and ivermectin 3.15% and closantel administration to all * Corresponding author. E-mail address: franklin.riet@pq.cnpq.br (F. Riet-Correa). Contents lists available at ScienceDirect Toxicon: X journal homepage: www.journals.elsevier.com/toxicon-x https://doi.org/10.1016/j.toxcx.2020.100024 Received 30 November 2019; Received in revised form 12 January 2020; Accepted 13 January 2020