Neurotoxicosis in horses associated with consumption of Trema micrantha

Abstract

T. micrantha poisoning in horses causes predominantly a neurological disease, with minimal to absent hepatic lesions.

Toxic pneumopathy by Trema micrantha in sheep in the State of Santa Catarina, Brazil

“…aspera seems to act as a hepatic toxin leading to the accentuation of the lobular pattern in sheep, as observed in the present study to a lesser extent (Mulhearn 1942, Oelrichs 1968). In horses, this glycoside causes severe hepatocellular necrosis (Hill et al 1985, Bandarra et al 2010, Lorenzett et al 2017. Some plants also cause acute liver necrosis, such as Cestrum axillare, Cestrum parqui, Cestrum corymbosum, Cestrum intermedium, Sessea brasiliensis, Vernonia mollissima, Vernonia rubricaulis, Xanthium sp., and Dodonaea viscosa (Riet-Correa et al 1986, Chaulet et al 1990, Gava et al 1991, Marinho et al 2018, Soares et al 2018, Barbosa et al 2020, Pohl et al 2021, Zamboni et al 2021).…”

“…Vascular changes characterized by subcutaneous petechiae and hemorrhages in the thyroid and adrenal glands have been reported in horses, in addition to bloody content in the lumen of the small intestine (Bandarra et al 2010). In the brain, yellowish areas with friable multifocal to grayish to dark red coalescing foci can be observed mainly in the rhombencephalon, diencephalon, telencephalon, mesencephalon, and striatum, with the most severe lesions being in the pons (Lorenzett et al 2017). Spinal cord injuries (mostly in lumbar swelling) with edema and depressed dark areas in the dorsal and ventral horns are also reported, and the gray matter may be friable and yellowish in the sacral region of the equine species (Lorenzett et al 2017).…”

“…Trema micrantha is a tree that measures between 5 and 12 meters and belongs to the family Ulmaceae; it has a trunk measuring between 20 and 40 centimeters in diameter, leaves with a rough upper surface and a pubescent lower surface that measure 7-10 centimeters in length and 3-4 centimeters in width (Lorenzi 1992). The leaves of the plant are considered palatable for cattle and easily consumed by animals, especially when there is a shortage of forage (Traverso et al 2004), but T. micrantha is toxic to cattle (Traverso et al 2004), goats (Traverso et al 2003), sheep (Wouters et al 2013a), and horses (Lorenzett et al 2017).…”

“…There are two forms of poisoning by T. micrantha, the first is common in cattle, horses, and goats and is characterized by the accentuation of the lobular pattern of the liver (Traverso et al 2003, 2004, Bandarra et al 2010, Gava et al 2010, Lorenzett et al 2017, hemorrhages in the subcutaneous tissue, thyroid, and adrenal glands (Bandarra et al 2010), in addition to cerebral edema and foci of hemorrhage in the thalamus of horses (Lorenzett et al 2017). Jaundice and subcutaneous hemorrhages in the region of the scapula and sternum are described in goats, with an evident lobular, yellowish, friable pattern in the liver and edematous gallbladder and mesentery (Traverso et al 2003).…”

“…In addition to the aforementioned changes, petechiae and suffusions in the endocardium and all serosa of the organs of the abdominal cavity were reported in cattle, which also showed dry feces with mucus and blood, free clots in the abdominal cavity, edema and perirenal hemorrhage, and pale kidneys with multiple reddish spots in the cortical (Traverso et al 2004). The main histological changes in this form consist of massive hepatocellular necrosis and marked centrilobular hemorrhage in cattle and goats (Traverso et al 2003(Traverso et al , 2004, whereas fibrinoid degeneration of blood vessels and edema, perivascular hemorrhage and multifocal thrombosis associated with marked neutrophilic infiltrate, and occasional lymphocytes, plasma cells, and macrophages can also be observed in horses (Lorenzett et al 2017). In addition to liver damage, sheep also show Alzheimer type II astrocytes in the gray matter of the cerebral cortex, edema in the neuronal pericardium, and perivascular edema in the cervical segment of the spinal cord (Wouters et al 2013a).…”