Accidental poisoning by castor bean (Ricinus communis) cake in horses

Abstract

Ricinus communis is a shrub of the family Euphorbiaceae popularly known in Brazil as “mamona” or “carrapateira”. It is an oleaginous plant whose seeds have been used mainly in biodiesel production. Plant seed oil can be extracted mechanically or using solvents, generating castor bean cake and castor bean meal as by-products, respectively. Accidental ingestion of these by-products can cause poisoning in animals and humans, characterized by digestive signs resulting from the presence of a toxalbumin called ricin. Seed toxicity varies among animal species; in horses, the lethal dose of seeds is 0.1 g/kg of body weight. The literature presents plenty of studies addressing poisoning by R. communis in different animal species and in humans; however, reports are scarce and little information is available on the pathological aspects of poisoning regarding equines. Therefore, the present study aimed to describe the epidemiological, clinical and pathological aspects observed in an outbreak of accidental poisoning with castor bean cake in horses. The equines were supplemented with palm kernel (Elaeis guianeesis) cake; however, in the purchase of a new batch, there was an error in the order, and castor bean cake was requested instead. Four horses that received castor bean cake presented clinical signs indicative of colic, which started about 21 hours after administration. Three of these horses died, with clinical evolution from 2 to 4.5 hours; the other animal was treated with intravenous fluid and antibiotic therapy and non-steroidal anti-inflammatory drugs and recovered after five days. In the necropsy of two of these horses, the main lesions were found in the small intestine, where mucosae with pronounced redness and covered with a thin layer of yellow fibrous material were observed. In the intestinal lumen, there was a large amount of bloody liquid. The stomach was full, and dark lumps similar to crushed castor bean seeds were observed in the contents. The adrenal glands of both horses presented congestion and hemorrhage in the cortex. In microscopy, the main lesion was an acute, diffuse and accentuated fibrin-necrotic enteropathy affecting the jejunum. The diagnosis of castor bean cake poisoning was based on the circumstantial evidence of by-product consumption supported by clinical and pathological aspects. The results indicate that castor bean cake commercially available as fertilizer is extremely toxic when ingested, and there is a need for appropriate detoxification or labeling informing of its toxicity.

Phytotoxicological study of selected poisonous plants from Azad Jammu & Kashmir

“…To find relevant information, researchers who were undertaking ethno-veterinary research in Azad Jammu and Kashmir were consulted. The search was conducted initially in March to November 2019–2020 as part of a PhD dissertation [ 51 ]. An inclusive exploration commenced by all the earlier investigation in last 40 years (1981–2021) in different regions of the world was reviewed.…”

Plants causing poisoning outbreaks of livestock in South America: A review

“…Poisoning occurs in conditions of forage shortage or when the plant is cut and offered to animals. In Brazil, the poisoning has been reported in cattle ( Albuquerque et al, 2014 ), sheep ( Bianchi et al, 2018 ), horses ( Montão et al, 2018 ), and goats ( Machado et al, 2022b ). In Argentina, the poisoning is less frequent ( Marín et al, 2018 ).…”