Botha, C.J. (Christoffel Jacobus)Venter, ElnaUniversity of Pretoria. Faculty of Veterinary Science. Dept. of Paraclinical Sciences. Section Pharmacology and Toxicology2008-12-222008-12-222002Botha, CJ & Venter, E 2002, 'Plants poisonous to livestock Southern Africa (CD-ROM)' University of Pretoria, Faculty of Veterinary Science, Dept. of Paraclinical Sciences, Section Pharmacology and Toxicology, Pretoria, South Africa.http://hdl.handle.net/2263/8517Colour photos. Final web-ready size: JPEG. Photo 1: 31.8 kb, 96 ppi; Photo 2: 35.6 kb, 72 ppi; Photo 3: 21.3 kb, 72 ppi; Photo 4: 9.2 kb, 72 ppi. Original TIFF file housed at the Dept. of Paraclinical Sciences, Section Pharmacology and Toxicology, University of Pretoria.MECHANISM OF ACTION: In the rumen nitrate is reduced to nitrite and following absorption haemoglobin is oxidised to methaemoglobin.TOXICITY: • Great variations both inter- and intraspecies • Nitrate - c. 0,5 g/kg sheep - 5g/kg cattle • Nitrite - c. 20 mg/kg sheep - 100mg/kg cattle For soluble oxalate poisoning, go to Urogenital Menu.SYNDROMES: Nitrate/nitrite poisoning.SYSTEMS AFFECTED: Haemopoietic system.CLINICAL SIGNS: Acute poisoning: Respiratory System: • Hyperpnoea • Dyspnoea • Anoxia precipitated by exercise Central Nervous System: • Ataxia • Tremors • Weakness • Terminal convulsions (brain anoxia) Cardiovascular System: • Cardiovascular failure, syncope • Cyanosis • Methaemoglobinaemia: Blood & mucous membranes a dirty chocolate brown colour • Rapid weak pulse (drop in blood pressure) Gastrointestinal Tract: • Diarrhoea • Salivation (vomition) Abortion - especially last trimester For soluble oxalate poisoning, go the Urogenital Menu.NECROPSY: Macroscopical findings: • Cyanosis• Tarry, dark, red-brown to brown blood• Tissues and mucous membranes brown (Not apparent in every case) • Congestion • Petechial and ecchymotic haemorrhages on mucosal, visceral and serosal surfaces.HISTOPATHOLOGY: • Nothing unusual or pathognomonic For soluble oxalate poisoning, go the Urogenital Menu.TREATMENT: 1. Methylene blue. Acts as intermediate electron acceptor that accelerates the reaction between NADPH and methaemoglobin. 2. Ascorbic acid. Also used in dogs for paracetamol poisoning.©University of Pretoria. Dept. of Paraclinical Sciences, Section Pharmacology and Toxicology (Original and digital). Provided for educational purposes only. It may not be downloaded, reproduced or distributed in any format without written permission of the original copyright holder. Any attempt to circumvent the access controls placed on this file is a violation of copyright laws and is subject to criminal prosecution. Please contact the collection administrator for copyright issues.Plant poisoningToxicologyPlant poisoning in animalsPoisonous plantsNitrateNitriteMethaemoglobinPoisonous plants -- Toxicology -- Africa, SouthernVeterinary toxicologyStill Image