Importância econômica, epidemiologia e controle das intoxicações por plantas no Brasil

Amaranthus hybridus (syn. quitensis) intoxication in cattle in Argentina: Case report

Amaranthus spp. is a nephrotoxic plant with unknown toxic principle, affecting production animals worldwide, mainly in South America. The aim of this paper is to describe 5 spontaneous outbreaks of A. hybridus intoxication in beef cattle, where 7 autopsies were performed. Main gross findings were pale diffuse and enlarged kidneys. Microscopically, kidneys were characterized by severe tubular acute to subacute nephrosis, with dilatated tubules showing different degrees of epithelial degeneration and necrosis, and containing intraluminal eosinophilic hyaline casts. Intratubular birefringent crystals, compatible with oxalate, were observed under polarized light in kidneys from 3 autopsies. Positive von Kossa and red alizarin S staining confirmed the intratubular crystals as calcium deposits. This intoxication occurs mainly in stubble paddocks during summer and early autumn. The data from the present study suggests that oxalates were related to nephrotoxicity due to Amaranthus consumption.

Acute necrotic hepatotoxicity caused by Melanthera latifolia (Asteraceae) in cattle

This study aims to report a spontaneous and experimental intoxication in cattle by Melanthera latifolia (Asteraceae) for the first time, and to describe its epidemiological, clinical, and pathological findings. An outbreak of acute toxic hepatopathy in cattle occurred from December of 2021 to January of 2022 in a beef cattle farm from Rio Grande do Sul state, Southern Brazil, and resulted in 94 deaths from a herd of 430 animals. At necropsy, lesions consisted of enhanced lobular pattern of the liver, transmural gallbladder edema, and hemorrhages on the surface of multiple organs. The main microscopic lesion was marked hepatocellular necrosis in the centrilobular region associated with hemorrhage and infiltration of neutrophils. During the outbreak, multiple specimens of M. latifolia were noted in the paddocks where affected cattle were grazing and many showed signs of consumption. No other known acute hepatotoxic plants were found. Two 12-month-old steers were experimentally intoxicated with a single oral dose of the fresh plant (flowers, leaves, and less fibrous stalks). One bovine ingested a dose of 10  g/kg and was euthanized after 48 h, and the other ingested 15  g/kg and was euthanized 17 h later. Clinical signs, macroscopic, and microscopic lesions in both animals were similar to those observed in the spontaneous cases. Thus, this study demonstrates that M. latifolia was the cause of the outbreak of acute toxic hepatopathy with significant mortality in cattle. M. latifolia nor any plant of the genus Melanthera had ever been reported as toxic.

Toxic plants from the perspective of a "Quilombola" community in the Cerrado region of Brazil

A multi-disciplinary team surveyed ranchers at the Kalunga Historical and Cultural Heritage Site, in the Cerrado region of west central Brazil, to determine impacts promoted by toxic plants on cattle. The expedition to the Kalunga region was carried out by Brazilian and American researchers. Previously selected cattle ranch properties from "Vão das Almas", "Engenho II" and "Vão do Moleque" were visited. Twenty-four interviews were carried out with cattle ranchers and a questionnaire was applied to obtain information about outbreaks of native plant poisoning and their effects on livestock, and the use of local plants in phytotherapy. We classified problematic plants into three distinct categories. First, the toxic plants most cited by residents causing cattle losses were the flowers of Caryocar brasiliense Cambess ("pequi"), the fruits of Terminalia corrugata (Ducke) Gere & Boatwr. (Buchenavia tomentosa Eichler - "mirindiba" or "pau-pilão"), Eugenia dysenterica (Mart.) DC ("cagaita"), and Palicourea marcgravii A. St. Hil ("erva-café" or "cafezinho"). Secondly, other plants considered toxic, but causing less severe losses were Emmotum nitens (Benth.) Miers ("casco d'anta"), Indigofera lespedezioides (Kunth) ("timbozinho"), Ricinus communis L. ("mamona"), Pteridium esculentum (G. Forst.) Cockayne ("samambaia"), Stryphnodendron adstringens (Mart.) Coville ("barbatimão"), and Actinocladum verticillatum (Nees) McClure ex Soderstr. ("cambaúba"). The most important finding was the identification of the C. brasiliense flower as potentially toxic to cattle, which must be subject for future research. Further, we confirmed the toxicity and importance of P. marcgravii, E. dysenterica, and Terminalia corrugata. The survey highlighted phytotherapy plants used by the community, and greatly increased awareness by local livestock producers of poisonous plants for management purposes. We conclude that ethnobotanical knowledge, especially from the traditional community, is essential to understand livestock losses to toxic plants, and should be valued not only for reducing livestock losses, but also for cultural importance to the Kalunga communities in the Cerrado.

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

This paper reviews toxic plants for livestock in South America. We included 219 plants in this review, considering only the plants that caused at least one demonstrated outbreak of poisoning. Plants reported as toxic in other regions and present in South America, but with no confirmed outbreaks of poisoning in this region, are not included. We report the main aspects of the epidemiology, clinical signs, pathology and economical importance of the poisonings. Initially, the toxic plants are described based on their toxic compounds, but because the toxic compound is unknown in 92 (42%) of the plants we also classify them according to the affected system. This review highlights the great diversity of toxic plants capable of affecting livestock in South America, and for this reason studies in this regard should be intensified.

Acetogenin-induced fibrotic heart disease from avocado (Persea americana, Lauraceae) poisoning in horses

Poisoning by avocado (Persea americana) has been confirmed in sheep, goats, dogs, rabbits and ostriches. The clinical signs and lesions are attributed to the acetogenin, persin. Little is known regarding the epidemiology, clinical signs, lesions and therapy caused by acetogenin-induced heart damage. During the two-year study, we investigated a horse farm with six horses that often fed themselves with P. americana leaves or mature fruit pulp and skin on the ground. Two horses died, and one underwent necropsy, histopathology, and immunohistochemistry using the anti-cardiac troponin C (cTnC). Grossly and histopathologically, there was severe cardiac fibroplasia. Immunohistochemically, there was a multifocal decrease or negative expression in the cTnC cardiomyocytes' cytoplasm. Persea americana leaves were confirmed in the alimentary tract using botanical anatomy and molecular techniques. The chemical investigation by (LC-ESI-MS) revealed the presence of the acetogenins, persin and avocadene 1-acetate from P. americana. Persin was present in leaves and fruits (seed and pulp), while avocadene 1-acetate was found in leaves and fruits (seed, peel, and pulp) with a higher concentration in the pulp. Four other horses have been examined by electrocardiogram, echocardiogram and serum Troponin 1 (cTnI). To establish a causal effect of consumption of P. Americana and heart fibroplasia in horses, long-time experiments must be carried out.

Causes of death in beef cattle in southern Brazil

We determined the prevalence of diseases and pathogens associated with mortality in beef cattle in the State of Rio Grande do Sul, Brazil, based on pathology laboratory submissions. Postmortem examinations were conducted on 1,277 beef cattle that died between 2008 and 2018. Information regarding age, time of the year, breed, and regional location were analyzed statistically. Most cattle were from the surrounding region of Porto Alegre, and 78.7% of the analyzed cases had diagnostic value. The diagnostic category with most cases was infectious and/or parasitic diseases (60%), followed by toxic and toxicoinfectious (25%). Most cases occurred in the fall. Major disease conditions identified included hemoprotozoal infection (18.2%), rabies (8.2%), and plant intoxications by Senecio spp. (8.5%) and Pteridium arachnoideum (4.6%). Hemoprotozoal infection occurred at a higher frequency in young cattle, mainly in animals up to 1 y old. Intoxication by Senecio spp. was more frequent in cattle 2-3 y old.

Phytochemistry and teratogenic potential of Mimosa tenuiflora (willd.) poir. (Fabaceae) in ruminants: A systematic review

Mimosa tenuiflora (Willd.) Poir. (Fabaceae) is a plant native to Brazil and occurs in the phytogeographic domains of Caatinga and Cerrado. Relevant studies have investigated the chemical components of this plant and others have already demonstrated its teratogenic potential. It has been proven that this plant causes congenital malformations in farm animals and, consequently, financial losses to farmers in the Brazilian semiarid region. The present work aimed to carry out a bibliographic survey on the teratogenic effects of M. tenuiflora in ruminants and to group the chemical compounds occurring in this species. For this, databases were consulted and twenty-four articles published in the last 30 years (1990-2020) were included. According to the scientific documents analyzed, M. tenuiflora has embryotoxic, fetotoxic and abortive potential in farm animals, especially sheep and goats. The main classes of chemical compounds present in this species are alkaloids, saponins, flavonoids, and terpenoids. It is likely that some of these substances, mainly the indole alkaloid N,N-dimethyltryptamine, are related to the teratogenic effects reported in ruminants in the Brazilian semiarid region.

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.

A volatolomic approach using cerumen as biofluid to diagnose bovine intoxication by Stryphnodendron rotundifolium

An innovative volatolomic approach employs the detection of biomarkers present in cerumen (earwax) to identify cattle intoxication by Stryphnodendron rotundifolium Mart., Fabaceae (popularly known as barbatimão). S. rotundifolium is a poisonous plant with the toxic compound undefined and widely distributed throughout the Brazilian territory. Cerumen samples from cattle of two local Brazilian breeds ('Curraleiro Pé-Duro' and 'Pantaneiro') were collected during an experimental intoxication protocol and analyzed using headspace (HS)/GC-MS followed by multivariate analysis (genetic algorithm for a partial least squares, cluster analysis, and classification and regression trees). A total of 106 volatile organic metabolites were identified in the cerumen samples of bovines. The intoxication by S. rotundifolium influenced the cerumen volatolomic profile of the bovines throughout the intoxication protocol. In this way, it was possible to detect biomarkers for cattle intoxication. Among the biomarkers, 2-octyldecanol and 9-tetradecen-1-ol were able to discriminate all samples between intoxicated and nonintoxicated bovines. The cattle intoxication diagnosis by S. rotundifolium was accomplished by applying the cerumen analysis using HS/GC-MS, in an easy, accurate, and noninvasive way. Thus, the proposed bioanalytical chromatography protocol is a useful tool in veterinary applications to determine this kind of intoxication.

Epidemiological aspects of natural poisoning by Prosopis juliflora in ruminants in semiarid areas of the state of Bahia, Brazil, invaded by the plant

ABSTRACT: Poisoning by Prosopis juliflora (mesquite) leads to neurological signs, cachexia and death, mainly in cattle and goats. Although the uncontrolled spread of mesquite in the Caatinga biome (biological invasion), which alters the epidemiological conditions of intoxication by this plant, has been proved for approximately 20 years, strategies for its control and prophylaxis still remain out of date. These new epidemiological conditions have allowed the uncontrolled consumption of large amounts of in natura mesquite pods by ruminants for long periods in invaded pastures, thus resulting in increased history of poisoning. This study aimed to describe the new epidemiological aspects of P. juliflora poisoning in cattle and goats, 78 years after the introduction of this plant in the country, with emphasis on its degree of invasion, and to update the control and prophylaxis measures of this intoxication and the mapping of areas of outbreak occurrence in the semiarid region of the state of Bahia, Brazil. Seven outbreaks of natural mesquite poisoning, two in goats (OB 1 and OB 2) and five in cattle (OB 3, OB 4, OB 5, OB 6, and OB 7), were studied in loco in the municipalities of Juazeiro, Iaçu, Tucano, Santa Teresinha, Barra do Mendes, Barra and Tabocas do Brejo Velho. In the studied outbreaks, clinical-epidemiological (OB 1 to OB 7) and histopathological (OB 1, OB 2, OB 3, and OB 5) findings were compatible with mesquite poisoning, and this was the first anatomopathological proof of poisoning by this plant in this state. In addition, in the state of Bahia, disease occurs in an area approximately three times larger than previously known. On the farms investigated, mesquite introduction occurred between 1980 and 2005, through the single planting of an average of 33 seedlings. Since then, propagation of this plant has occurred progressively, with gradual invasion of native pastures, which enabled the evaluation of plant spread (biological invasion) on these farms 15 (OB 2), 25 (OB 7), 30 (OB 5 and OB 6), 35 (OB 3) and 40 (OB 1 and OB 4) years after its introduction. Historical information on the introduction and spread of mesquite in the state of Bahia had never been analyzed. In 2020, a degree of mesquite invasion an average 59.57% was verified in the pastures of the seven farms where the outbreaks occurred. The great biological invasion capacity of this plant drew attention, especially in OB 5. The high degree of mesquite invasion observed (new epidemiological conditions) justifies the increased number of cases of poisoning observed in this study. Processing of P. juliflora pods (grinding) was not carried out on any farm (OB 1 to OB 7), and ruminants uncontrollably consumed large amounts of pods in natura for long periods in invaded pastures, which allowed massive dispersal of seeds through feces over decades. The main factors responsible for the gradual invasion of pastures by mesquite over time were absence of crop management plans (silvicultural treatments) and lack of knowledge by producers on disease etiology. Given the new epidemiological conditions, restriction of animal access to in natura pods in pastures and supply of mesquite bran are crucial for the control and prophylaxis of this poisoning, as consumption of in natura pods had a strong correlation with the high degree of invasion in the pastures where the seven outbreaks occurred. Additionally, although the commercialization of pods and exploitation of wood of mesquite trees can provide livestock farmers with extra income - being the correct management for areas invaded by this plant, such practice is either not yet known or not carried out technically or satisfactorily by farmers. In addition to being a threat to the Caatinga’s biodiversity, the increasing invasion of semiarid areas by mesquite 78 years after its introduction in the Northeast region of Brazil, is a risk for herds, since the occurrence of poisoning outbreaks may become more frequent. Therefore, it is highly advisable that effective measures be adopted to control P. juliflora propagation.

Techniques for prevention and control of poisoning by sodium monofluoroacetate (MFA)-containing plants in ruminants

ABSTRACT: Monofluoroacetate (MFA)-containing plants cause sudden death associated with exercise in ruminants, and are responsible for significant losses in Brazilian livestock, estimated at 500,000 bovine deaths annually. Most of the times, the control and treatment of this type of poisoning are not efficient, because disease evolution is superacute, usually causing the death of the animal. Due to the difficulty in controlling this intoxication, several studies have suggested alternatives to prevent it, mainly by making animals resistant to the MFA present in these plants or by avoiding their consumption. This literature review addresses the techniques used experimentally to control the poisoning of ruminants by plants containing MFA. The first studies carried out in Brazil demonstrated that goats and sheep that continuously receive non-toxic doses of plant containing MFA show greater resistance to poisoning than untreated animals, and that this resistance can be transmitted by ruminal fluid transfaunation, suggesting that poisoning occurs due to the presence of bacteria that hydrolyze MFA in the rumen. Based on this hypothesis, several MFA-hydrolyzing bacteria were isolated (Enterococcus faecalis, Bacillus sp., Paenibacillus sp., Burkholderia sp., Cupriavidus sp., Staphylococcus sp., Ancylobacter sp., Ralstonia sp., Stenotrophomonas sp., Pigmentiphaga kullae, and Ancylobacter dichloromethanicus). When some of these bacteria were administered intraruminally, they provided the animal with a different level of protection against poisoning. However, it was observed that protection is gradually lost when the bacterium administration is interrupted. Consequently, to obtain more efficient protection, these bacteria should be administered continuously, probably in the form of probiotics. In another assay, MFA was administered to sheep at non-toxic doses to test the hypothesis that this substance could induce the multiplication of bacteria that hydrolyze it in the rumen. There was no increase in resistance to poisoning after administration of MFA; however, no signs of poisoning were observed when animals received trifluoroacetate and no clinical signs were verified when they were challenged with toxic doses of MFA; in contrast, all control animals presented clinical signs. These results suggest that trifluoroacetate induces the proliferation of MFA-degrading bacteria, and can be used in intoxication prophylaxis. The conditioned food aversion technique, using lithium chloride, has been successfully used experimentally to prevent ruminants from ingesting plants that contain MFA. Another alternative tested was the spraying of Amorimia septentrionalis with the endophytic bacterium Herbaspirillum seropedicae, which degrades MFA, resulting in decreased concentration of this compound in the plants. In conclusion, several experimental techniques have been proved efficient in the control and prophylaxis of MFA-containing plant poisoning; however, none of these techniques are available commercially. Further experiments, mainly in the field, should be carried out to adapt some of these techniques to the conditions of extensive breeding in the numerous areas where MFA-containing plants occur.

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.

Jürgen Döbereiner: a life dedicated to science

ABSTRACT: Dr. Jürgen Döbereiner was born in Germany, on the 1st of November 1923, and lived in Brazil for 68 years during which time he developed a range of scientific projects in veterinary pathology and related disciplines. His main interests were the identification of new poisonous plants and mineral deficiencies and the causes of “cara inchada” (“swollen face” a periodontal disease) and botulism in livestock. This research has resulted in the improved health and saving of hundreds of thousands of animals, mainly cattle, annually, and is consequently of enormous economic value to the country. This contribution remains largely under appreciated. He was also involved in organizing diagnostic methods for identifying infectious diseases such as African swine fever and glanders in horses. One of his other major achievements has been the foundation and editing of specialized scientific journals for the documentation of veterinary science research results. At the beginning of his career in the 1950s, he and colleagues from the Institute for Animal Biology (IBA) were struggling to find a national scientific journal where research results from veterinary medicine could be published with practical application to the Brazilian reality. In consequence, the team founded “Arquivos do Instituto de Biologia Animal” and published three volumes (1959-1961). He then founded and edited “Pesquisa Agropecuária Brasileira” (The Brazilian Journal of Agricultural Research”) that included a veterinary section. A series of veterinary volumes were published (1966-1976). Finally, in 1978 he helped create the Brazilian College of Veterinary Pathology (CBPA) that published “Pesquisa Veterinária Brasileira” (The Brazilian Journal of Veterinary Research) from 1981. The main goal was to communicate the most relevant disease problems of Brazilian livestock, in particular pathology and related subjects such as epidemiology, clinical study series and laboratory diagnosis to field veterinarians and academics. Dr. Jürgen Döbereiner was president of CBPA (1978-2018) and chief editor of “Pesquisa Veterinária Brasileira” (1981-2018). He passed away on the 16th of October, 2018, at the age of 94 at his home in Seropédica/RJ, Brazil.

Economic losses due to Vernonia rubricaulis poisoning in cattle

ABSTRACT: Vernonia rubricaulis is a hepatotoxic plant found in the Pantanal biome. Under natural conditions, it is responsible for highly fatal poisonings in cattle. From January 1999 to December 2016, 33 outbreaks of V. rubricaulis poisoning were recorded, resulting in 1509 bovine deaths, of which 719 (47.6%) were adult females, 413 (27.4%) were adult males, 244 (16.2%) adult cattle with no information about sex and 133 (8.8%) calves. The coefficients of morbidity, mortality and lethality were respectively 2.79%, 2.77% and 99.24%. Most outbreaks occurred in properties containing up to 1,000 cattle, where the most significant economic impacts were also observed. Among the total recorded deaths, the total direct monetary loss was estimated at US$764,893.33, which represents an average of 3.05% of the total assets (US$25,090,683.51) of the herds involved in the outbreaks. The plant can cause more severe damage to properties with less than 500 cattle, and can reach 50% of the total value of the herd. In comparison to other methods, the methodology used in this study has an economic impact consistent with reality, not overestimating the losses. Toxic plants, such as V. rubricaulis, can cause significant economic losses in the extensive systemic livestock, and it is important decision-making and prophylactic management to avoid the occurrence of poisoning in the herds.

Evaluation of resistance to natural poisoning by Amorimia septentrionalis in goats which had received sodium monofluoroacetate degrading bacteria

ABSTRACT: Amorimia septentrionalis is an important sodium monofluoroacetate (MFA) containing plant that causes sudden death in ruminants in northeastern Brazil. MFA degrading bacteria are being used in the prevention against poisoning by this plant. The aim of this study was to evaluate if goats which had per os received MFA degrading bacteria remained resistant when exposed to natural poisoning by A. septentrionalis. Eighteen goats were randomly distributed into three groups: the goats of Group 1 previously received, during 40 days, a solution containing the bacteria Ralstonia sp. and Burkholderia sp., those goats in the Group 2 received the bacteria Paenibacillus sp. and Cupriavidus sp. and goats from Group 3 did not receive any bacteria. After the administration period, during 60 days, the animals of all groups were released to graze on a one hectare paddock, with significant amount of A. septentrionalis. They were observed daily for the spontaneous consumption of A. septentrionalis leaves and the occurrence of clinical signs of poisoning or sudden death. Goats from all groups consumed significant amounts of A. septentrionalis during the experimental period. Goats that did not receive MFA-degrading bacteria (Group 3) became sick and died from the 25th to the 27th day of the experiment, whereas the goats of the groups that received MFA-degrading bacteria showed only clinical sings when A. septentrionalis regrowth after the 55th day of the experiment. The days elapsed from field observation to death of Group 3 goats (25.5±0.9 days) were significantly lower (p<0.05) than Group 1 (58.6±1.3 days) and Group 2 (57.8±1.5 days). Thus, it can be concluded that administration of MFA degrading bacteria increases the resistance to natural poisoning by A. septentrionalis.

Plantas tóxicas para ruminantes e equídeos do estado de Sergipe

RESUMO: Em um levantamento feito nos anos de 2015 e 2016 no estado de Sergipe, com o objetivo de conhecer as plantas tóxicas para ruminantes e equídeos, foram visitadas propriedades rurais em 16 municípios, englobando as mesorregiões do litoral, agreste e sertão. Para isso foram realizadas entrevistas a 32 produtores e 10 a médicos veterinários da região. De acordo com o levantamento, Amorimia spp., Crotalaria retusa, Ipomoea asarifolia, Palicourea aeneofusca e Poiretia punctata são responsáveis por mortes de animais gerando prejuízos consideráveis aos produtores. Surtos esporádicos de intoxicações por Ipomoea carnea subsp. fistulosa, Mimosa tenuiflora, Pannisetum purpureum e Manihot esculenta também foram relatados. Alguns produtores relataram surtos isolados de intoxicações por Ziziphus joazeiro e citrus sp, plantas não conhecidas anteriormente como tóxicas.

Toxic plants affecting the nervous system of ruminants and horses in Brazil

ABSTRACT: This review updates information about neurotoxic plants affecting ruminants and equidae in Brazil. Currently in the country, there are at least 131 toxic plants belonging to 79 genera. Thirty one of these poisonous plants affect the nervous system. Swainsonine-containing plants (Ipomoea spp., Turbina cordata and Sida carpinifolia) cause numerous outbreaks of poisoning, mainly in goats, but cattle and horses are occasionally affected. The poisoning by Ipomoea asarifolia, a tremorgenic plant, is very common in sheep, goats and cattle in the Northeastern region and in the Marajo island. Poisoning by the pods of Prosopis juliflora are frequent in cattle in Northeastern Brazil; occasionally this poisoning affects goats and more rarely sheep. Some poisonings by plants, such as Hybanthus calceolaria, Ipomoea marcellia and Talisia esculenta in ruminants and Indigofera lespedezioides in horses were recently described and needs to be accurately investigated about its occurrence and importance. Other plants poisonings causing nervous signs in ruminants and equidae are less important, but should be considered for the differential diagnosis of neurologic diseases.

Embryonic death and abortion in goats caused by ingestion of Amorimia septentrionalis

ABSTRACT: Amorimia spp. are sodium monofluoroacetate (MFA) containing plants causing sudden death in ruminants. In a previous study, Amorimia rigida caused abortion in one of the five pregnant sheep that received the plant suggesting that it may cause reproductive losses. This work aimed to study the embryotoxic and fetotoxic effects of Amorimia septentrionalis in goats in the Brazilian northeastern semi-arid region. The effects of A. septentrionalis on pregnancy were studied in 16 goats, divided into four groups according to their gestational period. In Groups 1, 2 and 3 the administration of A. septentrionalis at the daily dose of 5g of leaves per kg body weight was started on the 18th, 36th and 93th days of gestation, respectively. Goats from Group 4 did not ingest the plant. When the goats presented severe signs of poisoning the administration of the plant was suspended. Groups 1, 2 and 3 ingested the plant for 7.25±2.87, 9.25±2.21 and 12.50±0.57 days, respectively. All the goats recovered 7-12 days after the end of the administration of the plant. In Group 1, all the goats had embryonic death 6.25±3.59 days after the end of the ingestion of the plant. In Group 2, three goats aborted at 53, 54 and 78 days of gestation. Two goats from Group 3 gave birth normally and the other two aborted at 114 and 111 days of gestation. It is concluded that Amorimia septentrionalis is a sodium monofluoracetate-containing plant that causes embryonic deaths and abortions in goats that ingest non-lethal doses of the plant.

Aspectos epidemiológicos, clínico-patológicos e diagnóstico precoce da seneciose bovina no Oeste do Rio Grande do Sul

RESUMO: A ingestão de Senecio spp. (maria-mole) é, possivelmente, a principal causa de morte de bovinos por agentes tóxicos nas regiões central e sul do Rio Grande do Sul. Ao considerar a limitação de informações acerca dessa condição no Oeste do Rio Grande do Sul, esse trabalho objetiva descrever os principais aspectos epidemiológicos e clínico-patológicos da seneciose em bovinos nessa região. O estudo foi realizado por meio da aplicação de questionários em 16 propriedades rurais de municípios da região que apresentaram casos suspeitos da intoxicação em bovinos, de agosto de 2011 a março de 2014. Durante as visitas as propriedades foram coletadas plantas do gênero Senecio para identificação botânica, bem como se procedeu a coleta de fragmentos de fígado através de biópsia transtorácica para confirmação da intoxicação. As espécies de Senecio mais frequentes nas propriedades foram S. brasiliensis e S. heterotrichius. De um total de 88 bovinos, de nove propriedades distintas, que apresentaram falha no ganho de peso, 69 animais (aproximadamente 80%) foram positivos para seneciose crônica por apresentarem lesões características da intoxicação, tais como fibrose periportal (78% dos casos), megalocitose (76% dos casos) e proliferação de ductos biliares (68% dos casos), classificadas entre discretas e acentuadas. O trabalho confirmou a ocorrência da doença, mesmo em bovinos sem sinais clínicos evidentes. Os resultados obtidos nessas avaliações foram fundamentais para orientar proprietários e técnicos quanto às principais características da doença e às formas de controle a serem adotadas. O emprego da biópsia hepática possibilitou o diagnóstico precoce da intoxicação e auxiliou os criadores quanto ao descarte mais criterioso de bovinos e a real situação da intoxicação no rebanho, minimizando as perdas econômicas.

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.

Spontaneous poisoning by Sida carpinifolia (Malvaceae) in horses

ABSTRACT: Sida carpinifolia poisoning causes a chronic neurodegenerative disorder associated with lysosomal storage by indolizidine alkaloids (swainsonine). The epidemiological, clinical, pathological and lectin histochemistry findings of an outbreak of natural poisoning by S. carpinifolia in horses in Rio Grande do Sul state, Brazil, are described. Five horses from a total of 15 that were kept on native pasture with large amounts of S. carpinifolia presented during 90 days clinical signs of progressive weight loss, incoordination, stiff gait and ramble, in addition to exacerbated reactions and locomotion difficulty after induced movement. Four horses died, and one of them was submitted for necropsy. At necropsy, no significant gross lesions were observed. Histological findings observed in the central nervous system were characterized by swollen neurons with cytoplasm containing multiple microvacuoles; these abnormalities were more severe in the thalamus, hippocampus, cerebellum and pons. Using lectin histochemistry, the pons and hippocampus sections stained positive for commercial lectin Con-A, sWGA and WGA. This study aimed to detail S. carpinifolia poisoning in horses to be included in the differential diagnoses of neurological diseases of horses.

Causas de morte em vacas leiteiras no Rio Grande do Sul

RESUMO: As causas de morte em vacas leiteiras no Rio Grande do Sul foram analisadas através de um estudo retrospectivo dos protocolos de necropsia de 600 vacas leiteiras examinadas entre os anos de 1998-2012. Do total de vacas analisadas 67,5% eram oriundas da Região Metropolitana de Porto Alegre, seguida das Regiões Nordeste Rio-Grandense 12,4% e Centro Oriental Rio-Grandense 10,4%. Quanto às raças, 76,5% eram holandesas, 9,8% Jersey e 13,7% misturas dessas raças. O diagnóstico definitivo foi possível em 85,8% dos casos. A categoria de doenças inflamatórias e parasitárias foi a principal causa de morte com 48,2% dos casos conclusivos, seguida por neoplasias (17,5%), doenças tóxicas e toxi-infecções (15,9%), doenças nutricionais e metabólicas (8,5%), doenças causadas por agentes físicos (7,4%) e outras doenças (2,5%). As principais enfermidades diagnosticadas em cada categoria foram: tristeza parasitária bovina (120 casos), linfoma (77 casos), intoxicação por Senecio spp. (23 casos), retículo pericardite traumática (19 casos), cetose e timpanismo (11 casos cada uma) e fulguração (5 casos).

Sudden death associated with Niedenzuella stannea (Malpighiaceae) in cattle in the State of Mato Grosso, Brazil: importance and epidemiological aspects

ABSTRACT: The aim of this study was to investigate the importance of an acute disease that was characterized by sudden death associated with exercise that affected cattle in the region of the Araguaia River, especially in the municipality of Torixoréu, southeastern Mato Grosso, Brazil. Between August and September 2013, eighty farms in the municipality were visited and the pastures of these farms were inspected. Epidemiological questionnaires were completed from 65 farms. A plant identified as Niedenzuella stannea (N. stannea) of the Malpighiaceae family was attributed to the cause of sudden death in cattle, what causes major economic losses. Sudden death reports have occurred since 1970, when livestock was introduced into the region, and sudden death reports still occur. Outbreaks were reported to occur from May to October, but mainly during the dry season between June and August. N. stannea was identified at 41 farms and was always found in near to rivers. The most effective plant control methods included plowing the pastures and fields followed by manual application of Tordon® (Picloram and 2.4D). The administration of 5g/kg of young leaves which were collected from a farm with a sudden death history in cattle also caused sudden death in a sheep. Thus, it is concluded that the sudden death of cattle in the region of the Araguaia River is caused by the consumption of N. stannea.

Natural production of fluorinated compounds and biotechnological prospects of the fluorinase enzyme

Fluorinated compounds are finding increasing uses in several applications. They are employed in almost all areas of modern society. These compounds are all produced by chemical synthesis and their abundance highly contrasts with fluorinated molecules of natural origin. To date, only some plants and a handful of actinomycetes species are known to produce a small number of fluorinated compounds that include fluoroacetate (FA), some ω-fluorinated fatty acids, nucleocidin, 4-fluorothreonine (4-FT), and the more recently identified (2R3S4S)-5-fluoro-2,3,4-trihydroxypentanoic acid. This largely differs from other naturally produced halogenated compounds, which totals more than 5000. The mechanisms underlying biological fluorination have been uncovered after discovering the first actinomycete species, Streptomyces cattleya, that is capable of producing FA and 4-FT, and a fluorinase has been identified as the enzyme responsible for the formation of the C-F bond. The discovery of this enzyme has opened new perspectives for the biotechnological production of fluorinated compounds and many advancements have been achieved in its application mainly as a biocatalyst for the synthesis of [¹⁸F]-labeled radiotracers for medical imaging. Natural fluorinated compounds may also be derived from abiogenic sources, such as volcanoes and rocks, though their concentrations and production mechanisms are not well known. This review provides an outlook of what is currently known about fluorinated compounds with natural origin. The paucity of these compounds and the biological mechanisms responsible for their production are addressed. Due to its relevance, special emphasis is given to the discovery, characterization and biotechnological potential of the unique fluorinase enzyme.

Perdas econômicas pela condenação em matadouro frigorífico de fígados de bovino por fibrose causada por ingestão de Braquiaria spp

Resumo: A ingestão crônica de braquiária induz lesões hepáticas em bovinos caracterizadas por fibrose, atrofia do lobo esquerdo, hipertrofia compensatória do lobo direito e proliferação de ductos biliares. Tipicamente, essas lesões são associadas com agregados de macrófagos espumosos no parênquima hepático. Nesse trabalho foram estudados fígados com essas lesões num abatedouro frigorífico do Brasil Central e as perdas econômicas causadas pela condenação de tais fígados afetados foram estimadas. Durante o período estudado, 488.476 bovinos foram abatidos nesse matadouro frigorífico, dos quais 5.295 fígados foram condenados devido à fibrose, e 192 com lesão hepática foram estudados. Cálculos econômicos permitiram inferir que essas condenações representaram uma perda de R$ 108.817,60. Conclui-se que a condenação de fígados em razão de fibrose induzida pela ingestão de braquiária causa uma perda significativa para a indústria de carne e produtos bovinos devido à condenação de 23,6 toneladas de fígado em um ano em apenas um frigorífico, com perdas estimadas acima de R$ 100.000,00.

Resistência à intoxicação por Amorimia septentrionalis em caprinos, induzida pela inoculação ruminal das bactérias Pigmentiphaga kullae e Ancylobacter dichloromethanicus

No Brasil, estima-se que as intoxicações por plantas tóxicas que contém monofluoroacetato de sódio (MFA) causam a morte de aproximadamente 500.000 bovinosao ano. A inoculação ruminal de bactérias que degradam MFA tem sido proposta como uma forma de prevenir a intoxicação. O presente trabalho teve como objetivo avaliar, em caprinos, a resistência ao MFA presente em Amorimia septentrionalis, induzida por inoculação ruminal das bactérias Pigmentiphaga kullae e Ancylobacter dichloromethanicus. Doze caprinos, que nunca tiveram contato prévio com plantas que contêm MFA, foram divididos em dois grupos, com seis animais cada. No grupo 1, 60 mL de uma mistura das duas bactérias foi inoculada, diariamente, durante 10 dias em cada caprino. No grupo 2, os caprinos não receberam as bactérias. A partir do 10º dia de inoculação, A. septentrionalis foi administrada, diariamente, na dose de 5g/kg de peso vivo, sendo interrompida em cada animal após a observação dos primeiros sinais clínicos da intoxicação. Os caprinos do grupo 1 apresentaram sinais clínicos 5,83±2,56 dias após a administração da planta o que diferiu significativamente (p=0,037) dos caprinos do grupo 2, que apresentaram sinais clínicos aos 2,67±0,52 dias. A quantidade de planta ingerida pelos caprinos inoculados (28,83±12,97g/kg) e os não inoculados (12,03±3,65g/kg) para desencadear os sinais clínicos foi, também, estatisticamente diferente entre os grupos (p=0,025). Conclui-se que a administração intraruminal de Pigmentiphaga kullae e Ancylobacter dichloromethanicus induz resistência à intoxicação por plantas que contêm MFA.

Intoxicação por Ipomoea asarifolia em bovinos e ovinos no Rio Grande do Norte

Ipomoea asarifolia é uma das principais plantas tóxicas para ruminantes nas regiões Norte e Nordeste. A intoxicação ocorre na época das secas quando há escassez de forragem e é mais frequente em ovinos do que em outras espécies, porem casos espontâneos também são relatados em caprinos, bovinos e búfalos. Este trabalho relata a ocorrência de 18 surtos de intoxicação em bovinos por I. asarifolia que ocorreram de agosto de 2012 a fevereiro de 2013 no estado do Rio Grande Norte. De um total de 1704 bovinos, 202 (11,8%) adoeceram e 34 (2%) morreram. Em seis propriedades onde havia ovinos estes também se intoxicaram. Foram observados também sinais clínicos em bezerros e cordeiros confinados, sem acesso às pastagens, que se intoxicaram pela ingestão do leite das mães que ingeriam I. asarifolia a pasto.

Identificação e distribuição de lesões cardíacas em bovinos intoxicados por Amorimia exotropica

Amorimia exotropica é um arbusto escandente que pertence à família Malpighiacea, cujo princípio tóxico é o monofluoracetato de sódio e possui ação cardiotóxica em bovinos. Ela é a única representante, na região Sul do país, do grupo de plantas que causam morte súbita associada ao exercício. Este trabalho identificou e mapeou as lesões cardíacas observadas em bovinos intoxicados naturalmente por A. exotropica. Selecionaram-se nove corações bovinos, provenientes de um surto de intoxicação natural pela planta em uma propriedade de gado de corte do Rio Grande do Sul e procedeu-se o mapeamento de oito regiões topográficas distintas (ápice, ventrículos direito e esquerdo, septo interventricular, músculos papilares direito e esquerdo e átrios direito e esquerdo). À avaliação macroscópica quatro bovinos apresentaram lesão focal e bem delimitada no músculo papilar esquerdo. Estas áreas na histologia correspondiam à necrose de coagulação em diferentes estágios de evolução, similares a infartos. Todos os bovinos apresentavam necrose de cardiomiócitos, caracterizadas por retração e hipereosinofilia citoplasmática e fragmentação celular em todas as áreas amostradas. A severidade da injúria celular foi avaliada pela imuno-histoquímica anti-troponina C, a qual demonstrou acentuada perda e/ou diminuição de marcação citoplasmática em células necróticas. O músculo papilar esquerdo foi a região mais acometida nos casos de intoxicação por Amorimia exotropica.

Performance of sheep grazing in pastures of Brachiaria decumbens, Brachiaria brizantha, Panicum maximum, and Andropogon gayanus with different protodioscin concentrations

Brachiaria spp. are the most important grasses for ruminants in central-western Brazil. However, the use of these pastures is limited by their toxicity due to steroidal saponins. This experiment was conducted for 60 days to demonstrate the resistance of sheep raised on Brachiaria spp. pastures to steroidal saponin poisoning. The experiment was composed by 48 animals randomly divided into four groups (n = 12). Among them, 32 4- to 5-month-old castrated male crossbred Santa Inês sheep, originating from flocks that had been grazing on Brachiaria spp. for more than three consecutive years, and 16 were non-adapted (naïve) sheep from flocks that never had prior contact with pastures of Brachiaria spp. were randomly divided into four groups. Each of the four experimental groups was composed by eight adapted and four non-adapted animals. The four experimental groups were introduced into paddocks, each of which contained a single grass: either Brachiaria decumbens, Brachiaria brizantha, Panicum maximum, or Andropogon gayanus. The addition of the naïve sheep to the groups was designed to detect pastures' toxicity to naïve sheep and to adjust the stocking rate to optimize the use of forage. The weight gains of sheep grazing on B. decumbens, B. brizantha, and P. maximum were similar; however, the A. gayanus group showed lower weight gains compared with the other groups (P < 0.05). The mean serum activities of γ-glutamyltransferase in the sheep grazing on B. decumbens were higher than those in the sheep from the other groups. No significant differences among the groups were found in aspartate aminotransferase, creatinine, albumin, or total protein serum concentrations. No clinical signs were observed in the adapted sheep in any of the pastures. Of the four non-adapted sheep introduced into the B. decumbens pasture, two showed clinical signs of steroidal saponin poisoning, and one died. No clinical signs were observed in the non-adapted sheep in the other pastures. The saponin (protodioscin) concentrations in the pastures varied from 3.3 to 12.2 g/kg DM in B. decumbens, from 2.8 to 9.1 g/kg DM in B. brizantha, and from 1 to 1.5 g/kg DM in A. gayanus. No saponins were found in P. maximum. It is concluded that sheep from flocks reared in pastures of B. decumbens and B. brizantha were resistant to steroidal saponin poisoning and showed similar weight gains to those of sheep grazing in other tropical pastures.