Cistus salviifolius Toxicity in Cattle.

Toxicity related to consumption of Cistus sp. pl. has been described in ruminants in some countries. This report describes the clinical and pathological findings of Cistus salviifolius toxicosis in 3 beef cattle herds located in 2 different areas of Sicily, Italy. Outbreaks were observed after grazing in poor winter pasture where C. salviifolius was abundant. Mean morbidity and mortality were 29% and 21%, respectively. Most of the affected animals (6 to 36 months old) showed anorexia, weight loss, and pollakiuria culminating in recumbency and death. Occasionally, abortion and neurological signs were observed. In animals with acute signs, there was a moderate decrease of sodium and chloride concentrations in serum. Animals with chronic signs showed an increase of serum urea, creatine phosphokinase (CPK), aspartate transaminase (AST), lactate dehydrogenase (LDH), and phosphorus and a decrease in total serum protein, calcium, chloride, and magnesium concentrations. Moderate anemia and slight neutropenia, lymphocytosis, and eosinophilia were detected in all groups. At necropsy, the main lesion was severe distention of the urinary bladder with turbid hemorrhagic urine and crystalluria. Histologically, chronic cystitis, interstitial nephritis, eosinophilic enteritis, and nonsuppurative necrotizing hepatitis were observed. To our knowledge, this is the first report of C. salviifolius toxicosis in cattle in Italy.

Oenantha Crocata: A Case Report of Multiple Poisoning with Fatal Outcome.

BACKGROUND: Plant poisonings are uncommon in adults, and rarely fatal. Oenantha crocata is a toxic plant growing in the humid grasslands of North America and Western Europe. CASE REPORT: We report here two adults who ingested Oenantha crocata roots, having mistaken them for edible tuberous radish. One developed vomiting and needed only 24 h symptomatic treatment, whereas the other suffered prolonged convulsions, cardiac arrest, and severe metabolic acidosis, leading to a fatal outcome. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Cases of poisoning with Oenantha crocata are rare and destabilizing. With increased interest in "natural" foods and team building by survival training, medical teams should be aware of the management for such poisoning.

Palicourea marcgravii (Rubiaceae) poisoning in cattle grazing in Brazil.

Palicourea marcgravii is the most important poisonous plant of cattle in Brazil. It contains monofluoroacetic acid and causes sudden death associated with exercise. Herein, we describe the temporal and spatial distribution of the toxic disease. The survey was based on the epidemiological, clinical, and pathological data of the Setor de Anatomia Patológica (SAP) of the Universidade Federal Rural do Rio de Janeiro (UFRuralRJ) to report outbreaks of poisoning by P. marcgravii, from 1953 to 2018. Clinical signs were peracute and included labored breathing, loss of balance, muscle tremors, lateral recumbency, and limb paddling. Gross lesions such as congestion of large vessels and edema and pulmonary congestion were observed. Multifocal areas of vacuolar hydropic degeneration of distal contorted tubule cells with nuclear pyknosis were observed in the kidneys. The plant is found in forests, and the poisoning occurs mainly after clearing forests for pasture, in areas of natural forest recovery called "capoeira," which provide a favorable environment for maintaining P. marcgravii growth. Outbreaks of P. marcgravii poisoning coincided with periods of creation of large deforested pastures in the Southeast and Midwest regions of Brazil, and the poisoning should be considered an additional risk after deforestation. The most effective prophylaxis is fencing off the forest areas that contain these plants.

Poisoning by toxic plants in Hong Kong: a 15-year review.

INTRODUCTION: Hong Kong has a great diversity of plants, many of which are toxic to humans. The aim of this study was to identify the plant species most commonly involved in cases of plant poisoning in Hong Kong and to provide clinicians with a reference tool for the diagnosis and management of plant poisoning. METHODS: We retrospectively reviewed all plant poisoning cases referred to the Hospital Authority Toxicology Reference Laboratory from 1 January 2003 to 31 December 2017. Demographics, clinical presentation, laboratory findings, treatment and outcomes of patients, as well as morphological identification and analytical testing of the plant specimens, were investigated. RESULTS: A total of 62 cases involving 26 poisonous plant species were identified, among which Alocasia macrorrhizos (Giant Alocasia), Gelsemium elegans (Graceful Jessamine), and Rhododendron (Azalea) species were the three most commonly encountered. Gastrointestinal toxicity (n=30, 48%), neurological toxicity (n=22, 35%), and hepatotoxicity (n=6, 10%) were the three most common clinical problems. Forty-nine (79%) and eight (13%) patients had mild and moderate toxicity, respectively; they all recovered shortly with supportive treatment. The remaining five (8%) patients experienced severe toxicity requiring intensive care support. Most patients (n=61, 98%) used the plants intentionally: as a medicinal herb (n=31), as food (n=29), and for attempting suicide (n=1). Reasons for using the poisonous plants included misidentification (n=34, 55%), unawareness of the toxicity (n=20, 32%), and contamination (n=6, 10%). CONCLUSIONS: Although most plant exposure resulted in a self-limiting disease, severe poisonings were encountered. Epidemiology of plant poisonings is geographically specific. Clinicians should be aware of local poisonous plants and their toxicities.

Respiratory Failure Due To Plant Poisoning: Nicotiana glauca Graham.

BACKGROUND: Cases of human poisoning associated with Nicotiana glauca Graham are quite rare. Patients may consume the plant by mistaking it for spinach or use it as a folk remedy. The toxin stimulates the acetylcholine receptors in the central and autonomic nervous systems. A prompt and appropriate supportive treatment is crucial for survival. CASE REPORT: A 72-year-old female with a known breast cancer was brought to our emergency department (ED) with complaints of nausea and vomiting. The patient stated that her complaints started 2 h after she had cooked and eaten a plant in the hopes that it would help cure her cancer. On the second hour after arrival, the patient became confused. It was observed that the chest wall movements had decreased and that the patient had difficulty breathing. Due to respiratory failure, orotracheal intubation was performed to secure the airway. A sample of the plant that was eaten was requested from the patient's relatives. According to an Internet search, the plant sample was identified as N. glauca Graham. The patient was diagnosed with N. glauca Graham poisoning. The patient was extubated after 30 h. On 3-month follow-up, the patient was neurologically intact and had no complaints related to poisoning. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Patients with incurable diseases such as cancer tend to try folk remedies and can end up in ED. In patients who present with muscle paralysis and respiratory failure, emergency physicians should consider N. glauca Graham as a cause of plant poisoning.

An outbreak of poisoning by Kalanchoe blossfeldiana in cattle in northeastern Brazil.

In the world, Kalanchoe species are primarily ornamentals and houseplants, but some have escaped cultivation and can be found in the field. In Latin America, there are no reports of spontaneous poisoning by Kalanchoe species in animals. This study aimed to describe the epidemiological, clinical, and pathological aspects of an outbreak of poisoning by Kalanchoe blossfeldiana in cattle in the semiarid region of Pernambuco, Brazil. Epidemiological and clinical data were obtained from the owner and veterinarian during technical visits. Prunings of this plant were disposed of in a pasture with a shortness of forage. Seventeen cattle had clinical signs, and thirteen died 4-5 days after the first clinical signs were observed. Clinical signs and gross and histological lesions include gastrointestinal, cardiovascular, and neuromuscular disorders. Kalanchoe spp. contain cardiotoxic glycosides, and the clinical signs and lesions in cattle of this outbreak were consistent with poisoning by plants that contain these toxins.

Hepatomyoencephalopathy Secondary to Cassia occidentalis Poisoning: Report of Three Cases from North India.

Cassia occidentalis is an annual tropical shrub causing toxicity in cattle. However, human case reports of its poisoning are scarce. We, here, report three young children, residents of Western Uttar Pradesh in North India, who presented with lethargy, jaundice, and altered sensorium after consumption of Cassia seeds. The toxidrome was defined as hepatomyoencephalopathy. The children were resuscitated, managed for acute liver failure, and subsequently discharged without sequel. Although few studies have previously documented this association, this is the first such case series documenting a direct causal relationship of Cassia to hepatomyoencephalopathy syndrome. Public and clinician awareness regarding this syndrome mimicking viral encephalitis has the potential to prevent further outbreaks.

Poisoning after Ingestion of Spartium junceum Seeds: Dose-Dependent Effects in Three Boys.

BACKGROUND: Spanish broom (Spartium junceum L.) is an ornamental, medicinal, and potentially poisonous plant. CASE REPORT: Three children, aged 5-6 years, were accidentally poisoned from ingesting a variable number of seeds of Spanish broom. This plant contains several quinolizidine alkaloids as cytisine, which act as an agonist of nicotinic acetylcholine receptors. The potential danger varies, depending on the dose. After having ingested one to two seeds, one of the boys was asymptomatic. A second boy ingested four to five seeds and presented some digestive problems with favorable clinical evolution. A third boy ingested seven to eight seeds, and presented with digestive and neurologic symptoms, as well as minor metabolic acidosis. In this case there was vomiting with remains of the seeds. He responded well to a gastric lavage and activated charcoal. He was discharged 24 h post ingestion. The intake within one to eight seeds was accompanied by moderate symptoms, with good response to treatment. Children poisoned by plants with nicotine-like symptomatology usually fully recover, but some fatal cases have been reported. Prevention is always a key aspect to consider so as to reduce the risk of poisoning. There is a lack of legislative measures, based on lists provided by experts, to regulate real or potentially poisonous plants in children's areas. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: This case serves as an example of accidental plant poisoning. For emergency physicians, it is usually complicated to identify the specific plant involved, so initial treatment often starts with basic measures (airway, breathing, and circulation).

Induction and transfer of resistance to poisoning by Amorimia (Mascagnia) septentrionalis in goats.

Amorimia septentrionalis contains sodium monofluoroactetate (MFA) and can cause acute heart failure in ruminants when ingested in toxic doses. In this study, we demonstrate that resistance to poisoning by A. septentrionalis can be improved in goats by the repeated administration of non-toxic doses of A. septentrionalis. We also show that increased resistance to poisoning by A. septentrionalis can also be achieved by the transfaunation of ruminal content from goats previously conditioned to be resistant to naïve goats. These methods of improving resistance require further study, but appear to provide potential management solutions to mitigate toxicity problems from A. septentrionalis, and perhaps other plant species containing MFA.

Toxic encephalopathy due to colchicine--Gloriosa superba poisoning.

Gloriosa superba, a flowering plant widespread in South and Southeast Asia, is implicated in many cases of self-poisoning. Colchicine is concentrated in the seeds and tubers and this mediates its toxicity. We describe a 28-year-old woman who developed delayed encephalopathy after eating G superba tubers. MR scan of brain showed bilateral symmetrical T2 basal ganglia hyperintensities in the caudate and lentiform nuclei. The delay in onset of encephalopathy is attributable to a direct-effect colchicine, probably mediated through its effect on microtubular transport.

A case of rotenone poisoning from ingesting Derris trifoliata Lour. (Tuba fruit/pod) in Malaysia.

Derris trifoliata is mainly found in mangrove area in tropical regions and the plant extract is traditionally used for fishing by poisoning. This is the first case report of rotenone poisoning in a child from ingesting Derris trifoliata seed. The child developed altered consciousness, vomiting, hypotension, metabolic acidosis, and acute kidney injury. Species identification of this case requires the collaborative efforts of various agencies. She survived from the poisoning with no neurological sequelae.

An appraisal of traditional knowledge of plant poisoning of livestock and its validation through acute toxicity assay in rats.

Background: Kashmir Himalaya hosts the most diverse and rich flora in the world, which serves as grazing land for millions of small ruminants in the area. While most plant species are beneficial, some can be poisonous, causing economic losses and animal health issues for livestock. Consequently, this study is the first comprehensive report on the traditional phyto-toxicological knowledge in District Muzaffarabad and the assessment of its authenticity through experimental studies in rats. Methods: The data regarding traditional knowledge was gathered from 70 key respondents through semi-structured interviews, which was quantitatively analyzed and authenticated through plant extract testing on Wistar female rats and comparison with published resources. Results: A total of 46 poisonous plant species belonging to 23 families and 38 genera were reported to be poisonous in the study area. Results revealed that leaves were the most toxic plant parts (24 species, 52.1%), followed by the whole plant (18 species, 39.1%), stem (17 species, 36.9%), and seeds (10 species, 21.7%). At the organ level, liver as most susceptible affected by 13 species (28.2%), followed by the gastrointestinal tract (15 species, 32.6%), nervous system (13 species, 8.2%), dermis (8 species, 17.3%), renal (7 species, 15.2%), respiratory (4 species, 8.7%), cardiovascular system (3 species, 6.5%), and reproductive system (2 species, 4.3%). The poisonous plant species with high Relative frequency citation (RFC) and fidelity level (FL) were Nerium oleander (RFC, 0.6; FL, 100), Lantana camara (RFC, 0.6; FL, 100), and Ricinus communis (RFC, 0.6; FL, 100). Experimental assessment of acute toxicity assay in rats revealed that Nerium oleander was the most toxic plant with LD50 of (4,000 mg/kg), trailed by Ricinus communis (4,200 mg/kg), L. camara (4,500 mg/kg), and Datura stramonium (4,700 mg/kg); however, other plants showed moderate to mild toxicity. The major clinical observations were anorexia, piloerection, dyspnea, salivation, tachypnea, constipation, diarrhea, tremor, itchiness, and dullness. Conclusion: This study showed that numerous poisonous plants pose a significant risk to the livestock industry within Himalayan territory, leading to substantial economic losses. Consequently, it is of utmost importance to conduct further comprehensive studies on the phytotoxicity of plants.

Plant poisonings in Australia: a retrospective series of calls to the Queensland Poisons Information Centre.

INTRODUCTION: There is little research to characterise plant poisoning in Australia. The aim of this project is to investigate plant exposures reported to a state poisons information centre. METHODS: This is a retrospective review of plant exposures reported to the Queensland Poison Information Centre (QPIC) between January 2019 and December 2021. Main outcome measures included patient demographics, plant exposure details, symptomatology, and management advice. RESULTS: QPIC received calls regarding 2766 plant exposures over the study period. Children aged 1-4 years were the commonest group exposed, accounting for 1295 (46.8%) exposures. The caller was usually a family member/caregiver (2036 [73.6%]) calling from home (2257 [81.6%]). Exposures were unintentional in 2722 (98.4%) cases, with the oral route being most common, occurring in 2264 (81.9%) cases.Plant groups most responsible for exposures included gastrointestinal irritants (536 [19.4%]), oxalates (522 [18.9%]), and non-toxic plants (442 [16.0%]). The plant involved was known in 2366 (85.5%) exposures, most commonly Euphorbiaceae (257 [9.3%]). Patients were asymptomatic (1644 [59.4%]) or had mild toxicity (1033 [37.3%]) in most exposures. Only 18 (0.6%) cases had moderate/severe toxicity, and this was most often due to recreational exposures by adults (9[0.3%]). Referral for medical review was advised in 407 (14.7%) cases, most commonly following exposures to Euphorbiaceae (140/407 [34.4%]), gastrointestinal irritants (52/407 [12.7%]), and oxalates (38/407 [9.3%]). CONCLUSIONS: The majority of plant exposures reported to QPIC are unintentional paediatric exposures. Most are asymptomatic or have mild toxicity. More severe toxicity is seen in adults with recreational plant exposures.

Laurel but Hardy: unintended poisoning, a case report of oleander misidentification as bay laurel.

Introduction: Nerium oleander is a toxic plant containing cardiac glycosides throughout all its parts, thereby posing severe health risks upon ingestion. The clinical manifestations of oleander poisoning closely resemble those of digoxin toxicity, encompassing a spectrum of gastrointestinal symptoms, neuropsychiatric disorders, and cardiac disturbances. This scientific case report describes a case of accidental intoxication resulting from the consumption of an oleander leaves infusion misidentified as bay laurel leaves. Case report: An 84-year-old patient consumed an oleander leaves infusion, and after four hours experienced gastrointestinal symptoms. He contacted the poison control center (PCC) and was advised to go to the emergency department (ED). Upon arrival, the patient presented stable vital signs without cardiac irregularities. The PCC recommended the administration of activated charcoal, vigilant monitoring, including electrocardiography (ECG). Subsequent ECGs assessments revealed the presence of third-degree atrioventricular block; in consultation with the PCC, digoxin-specific antibodies and external pacing were necessary. The patient was discharged on the eighth day in good hemodynamic condition, and outpatient follow-up visits showed clinical stability. Discussion: This study offers insights for the management of similar cases. The limitations of conventional assays in measuring oleander cardiac glycosides were observed, emphasizing reliance on clinical evaluation. The patient's trajectory, remaining asymptomatic despite severe ECG changes post-ingestion, underscores the importance of prolonged clinical monitoring.

Clinical Presentation, Electrocardiographic Findings, and Factors Related to the Hospitalization In Mad-Honey Intoxication.

Objectives: Mad-honey intoxication (MHI) often presents with all kinds of bradyarrhythmias. Despite numerous publications focused on clinical findings, we aim to evaluate poor prognostic implications, ischemia likely electrocardiography (ECG) changes, and detailed ECG findings of MHI in the largest series. Methods: This is a retrospective single-center study of 117 MHI patients admitted to emergency service. Results: The study had 26 (22.2%) females (median 52.5 years) and 91 (77.8%) males (median 51.0 years). Fifty-six (47.9%) patients had ischemia likely changes on ECG. Multivariate model demonstrated that beta-blocker usage (odds ratio (OR): 52.871; 95% confidence interval (CI): 3.618-772.554 (p=0.004)), atrioventricular junctional rhythm (AVJR) (OR: 5.319; 95%CI: 1.090-25.949 (p=0.039)), and quantity of mad-honey consumption (OR: 1.035; 95% CI: 1.008-1.063 (p=0.011)) are predictors of hospitalization. ROC curve analysis showed cutoff value of mad-honey consumption quantity 24.79 g had 57% sensitivity and 68% specificity for predicting hospitalization (AUC: 0.7, 95% CI: 0.55-0.816, p=0.027). In addition, all hospitalized cases were male. Conclusion: Our study has shown that male gender, AVJR, the quantity of mad-honey consumption, and beta-blocker usage are high-risk criteria for hospitalization in MHI patients. Furthermore, ischemia likely ECG changes is often observed with MHI even independently from hypotension or bradycardia.

Identification of antinutritional, antioxidant, and antimicrobial activity of plants that cause livestock poisoning in Bojonegoro Regency, Indonesia.

Background and Aim: The utilization of cassava leaves and peels, ceara rubber leaves, sweet potato leaves, Chinese Albizia leaves, and lophatheri leaves from Bojonegoro Regency has led to the poisoning of livestock due to antinutritional factors. Nevertheless, the plants are known to have bioactive components and potential antioxidant and antibacterial activity if appropriately processed. This study aimed to determine the antinutritional compounds as well as the antioxidant and antibacterial potential of these plants responsible for livestock poisoning in the Bojonegoro Regency. Materials and Methods: Extraction was performed by the maceration method using 70% (v/v) ethanol solvent. The samples were analyzed qualitatively to determine the presence of tannins, alkaloids, oxalates, cardiac glycosides, and cyanogenic glycosides. The antioxidant activity was determined using the 1,1-diphenyl-2-picrylhydrazyl method, while the antimicrobial activity was assessed by different testing concentrations (125, 250, and 500 mg/mL) against Staphylococcus epidermidis, Staphylococcus aureus, and Escherichia coli. Results: The ethanolic extract of the plants was found to contain antinutritional tannins, alkaloids, cardiac glycosides, and cyanogenic glycosides suspected of causing livestock poisoning. Despite the presence of these antinutrients, all extracts also had antioxidant and antibacterial potential. Cassava peels and sweet potato leaves had the highest antioxidant activity, whereas Chinese Albizia leaves had the most potent antibacterial activity. Conclusion: Cassava leaves and peels, ceara rubber leaves, sweet potato leaves, Chinese Albizia leaves, and lophatheri leaves obtained from Bojonegoro Regency and used as agricultural waste contain antinutritional factors but also possess potentially effective antioxidant and antimicrobial components.

Clinical and anatomopathological aspects of Stryphnodendron fissuratum poisoning in cattle and sheep.

Spontaneous and experimental Stryphnodendron fissuratum poisoning in cattle have been documented in the scientific literature. However, clinical and anatomopathological aspects of such poisoning are not fully understood. Thus, the objective of this study was to describe the clinical, biochemical, gross and microscopic findings of spontaneous Stryphnodendron fissuratum poisoning in cattle as well the experimental poisoning by this plant in sheep. Three outbreaks in cattle from different farms were analyzed. From these farms, S. fissuratum fruit specimens were collected and subsequently administered to six sheep. Some cattle showed clinical signs of poisoning such as blindness, apathy, dysphagia, excessive drooling, weight loss and photodermatitis. In the experimental poisoning condition, one sheep received only the peel of the fruit, one received the seed, and the others received the whole fruit. The whole fruit caused fatal poisoning in one sheep, which showed anorexia, excessive drooling, nystagmus, and paddling. Necropsies and clinical, histopathological, and pathological examination of poisoned cattle and sheep showed that the plant may cause acute renal failure along with extrarenal uremic lesions.

Toxicity of herbal medications suggested as treatment for COVID-19: A narrative review.

OBJECTIVES: In the absence of a definitive cure, herbal medications are gaining increasing popularity in the general public for treatment of coronavirus disease 2019 (COVID-19). Although many herbal preparations are safe and can be used without complication, serious toxicities do occur. This article focuses on the major characteristics and toxicities of herbal preparations that have been proposed as treatments for COVID-19. METHODS: A review was performed focusing on herbal preparations that have gained popularity as potential treatments for COVID-19. Some of these preparations have been directly recommended by government agencies, whereas others have gained popularity through various other news sources. RESULTS: The herbal preparations covered in this paper include the cardiac glycoside oleandrin, plants of the Datura genus, and herbs commonly used in traditional Chinese Medicine including plants of the Aconitum genus, bitter apricot seeds, ephedra, and licorice root. CONCLUSION: Although herbal preparations have been reported to aid in the treatment of COVID-19 with success, few clinical trials have been performed to evaluate their efficacy and instead rely mainly on in vitro studies and anecdotal reports. Furthermore, many of the herbal preparations suggested carry significant toxicities, and frontline healthcare workers should be aware of the common symptoms and toxidromes that result from these poisonings.

Photosensitization by Brachiaria ruziziensis in a sheep herd.

Some species of the genus Brachiaria are cultivated worldwide in tropical and subtropical climate regions as the main feed for ruminants. Several studies report photosensitization by Brachiaria decumbens, Brachiaria brizantha, and Brachiaria humidicola, but the poisoning by Brachiaria ruziziensis have been reported only twice. Cutaneous and hepatic lesions may be caused by the steroidal saponins present in the leaves or by the mycotoxin sporidesmin produced by the saprophyte fungus Pithomyces chartarum. The present report describes the clinical and pathological changes observed in an outbreak of hepatogenic photosensitization in sheep kept in B. ruziziensis pastures. In addition, the present study will provide a better understanding of the etiology of this photosensitization through the evaluation of the saponin protodioscin and the spore count of P. chartarum. Santa Inês and Lacaune mixed-breed sheep showed signs of photosensitization after feeding B. ruziziensis. Clinical signs included jaundice, apathy, dehydration, and photosensitization characterized by facial edema and cutaneous scars, especially in the ears. Pathological examination of the liver revealed diffuse infiltrates of foamy cells, rare multinucleated cells, and mild enlargement of hepatocytes (megalocytosis). The skin showed acute epidermal and dermal necrosis with occlusive thrombi. B. ruziziensis showed low levels of protodioscin (0.020 ± 0.024% in mature leaves and 0.065 ± 0.084% in sprouts) but high P. chartarum spore counts (mean of 479,844 ± 443,951 spores/g plant). Thus, sheep grazing B. ruziziensis pastures must be closely monitored because of the risk of photosensitization.

Sequential administrations of trifluoroacetate induce tolerance to Palicourea maccgravii, a monofluoroacetate-containing plant, in calves.

Monofluoroacetate (MFA) is considered one of the most toxic substances known. It is found naturally in plants, and causes sudden death syndrome in ruminants. Due to hyperacute evolution of poisoning and the absence of effective treatment, induction of resistance in animals might be the best tool to control MFA poisoning in ruminants. The objective of this study was to promote resistance in cattle against the toxic effects of MFA through its degradation by the ruminal microbiota after the administration of sodium trifluoroacetate (TFA). Ten calves were distributed into two groups: control group (n = 3) and treated group (n = 7). The calves in the treated group received 0.1 mg/kg live weight of TFA, whereas, those in the control group received water; both for 28 consecutive days. The calves were subjected to daily clinical evaluation and weekly blood biochemical determination to identify any signs of poisoning. After 28 d of administration of TFA or water, 2.0 g/kg body weight of Palicourea marcgravii leaves (containing 0.15% MFA) were administered using a stomach tube to determine the occurrence of resistance. The administration of TFA did not induce any clinical or biochemical changes in blood. The administration of P. marcgravii induced clinical changes in the calves of control group, but there was no change in the calves of the treated group. In conclusion, the administration of TFA to cattle can induce effective resistance against MFA poisoning.