Intoxicação por Senecio spp. em bovinos

Devido à grande importância da intoxicação por Senecio spp. em bovinos no Sul do Brasil e o impacto provocado pela doença, nessa tese estão incluídos dois artigos científicos acerca do tema. No primeiro trabalho, realizou-se uma revisão bibliográfica da intoxicação por Senecio spp. em bovinos. O objetivo desse estudo foi fornecer uma abordagem detalhada da intoxicação nessa espécie, com enfoque nos seguintes aspectos: princípio tóxico e patogenia, epidemiologia, sinais clínicos, diagnóstico e controle e profilaxia. No segundo trabalho são descritos os aspectos epidemiológicos, clínicos e anatomopatológicos de um surto de intoxicação natural por Senecio brasiliensis em bezerros e a caracterização e evolução das lesões hepáticas durante o surto. Um lote com 206 bovinos, fêmeas, sem raça definida, foi desmamado com aproximadamente quatro meses de idade e soltos em campo nativo com 25 hectares, com grande quantidade de Senecio brasiliensis em diferentes estágios. Os bovinos permaneceram nesse campo durante três meses e posteriormente foram transferidos para outra área. Na nova área, seis bezerras, com idades entre sete a oito meses, começaram a apresentar sinais clínicos de emagrecimento, fraqueza, diarreia e edema subcutâneo na região submandibular. Os seis bovinos morreram em um período de 15 dias e um deles foi necropsiado. Macroscopicamente, foi visualizado o primeiro (Padrão 1) dos três padrões distintos de lesão hepática dos bovinos desse surto, que se caracterizava por um fígado aumentado de tamanho, com os bordos arredondados e com superfície capsular e de corte alaranjada. Histologicamente, havia acentuada degeneração vacuolar hepatocelular difusa, bilestase, megalocitose, leve proliferação de ductos biliares e fibrose periportal. Dois meses após o início do surto, constatou-se que em um período de 20 dias adoeceram mais 28 bezerras e, dessas, 14 morreram. Os bovinos acometidos nessa segunda visita tinham idades entre nove a 10 meses. O principal sinal clínico observado foi fotossensibilização. Das 14 bezerras mortas, realizou-se a necropsia de duas delas, e foi visualizado o segundo padrão de lesão hepática nesse surto (Padrão 2). Os fígados estavam com a superfície capsular lisa e esbranquiçada, e moderadamente diminuídos de tamanho. Ao corte observou-se leve irregularidade do parênquima e áreas mais claras intercaladas com áreas avermelhadas. O aspecto histológico incluía acentuada fibrose periportal, marcada proliferação de ductos biliares, megalocitose, áreas multifocais de necrose de hepatócitos, hemorragia e lesões veno-oclusivas. A atividade sérica da gamaglutamiltransferase foi avaliada em 15 bovinos afetados nessa segunda visita à propriedade. Desses, 13 bezerras testadas apresentaram alterações nos valores, que variaram de 26-175 U/L. Em uma terceira visita à propriedade, sete meses após o início do surto, mais 27 bezerras adoeceram em um período de 40 dias e, dessas, 23 morreram, sendo três submetidas à necropsia. Evidenciou-se o terceiro padrão de lesão hepática (Padrão 3). O fígado dos três bovinos estava diminuído de tamanho e acentuadamente firme. A superfície capsular era lisa e esbranquiçada, e a superfície de corte apresentava-se difusamente acastanhada. Lesões histológicas semelhantes ao segundo padrão foram também constatadas no fígado dessas três bezerras. Na quarta visita à propriedade, realizaram-se biópsias hepáticas nos 163 bovinos restantes do lote. Lesões hepáticas características da intoxicação estavam presentes em 103 dos 163 bovinos submetidos à biopsia hepática.Poisoning of cattle by plants of the Senecio genus represents an important cause of death in cattle and has important economic repercussions in southern Brazil. Thus, in this thesis are included two scientific articles on the subject. At first work a bibliographic review was carried out on the disease. This review is intended to provide a detailed review of Senecio spp. intoxication in cattle and addresses issues regarding the toxic principle and pathogenesis of the disease caused by these plants and the epidemiology, clinical signs, diagnosis, control and prophylaxis of the disease. In the second article, the epidemiological, clinical and anatomopathological aspects of a spontaneous outbreak of Senecio brasiliensis in calves are described here. Characterization and evolution of liver lesions during the outbreak are also described. Two hundred and six 4-month-old female calves were weaned and placed in a 25-hectare pasture heavily infested by S. brasiliensis at of varying growth stages. The calves remained in this pasture for three months and were later transferred to another area where six calves aged 7-8- month-old developed clinical signs including unthriftiness, diarrhea, and subcutaneous dependent edema in the submandibular region. All these six affected calves died within 15 days from the onset of clinical signs and one of those was necropsied. Grossly the first of three patterns of hepatic lesions described in this report was observed and it was characterized by an enlarged liver, with round borders and an orange hue to the capsular and cut surfaces. Histologically there was marked diffuse vacuolar hepatocellular degeneration, bilestasis, hepatocellular megalocytosis, and mild bile duct proliferation and periportal fibrosis. Two months after the onset of the outbreak, in another visit to the farm, it was observed that an additional 28 calves got sick and 14 died. Affected calves observed in this second on-site visit were 9-10 month-old and their main clinical sign was photosensitization characterized by varying degrees of photophobia, tearing from the eyes, marked drooling, mucopurulent ocular discharge, increased nasal secretion, and ventral diphtheric glossitis. Two of the fourteen calves that died were necropsied and displayed the second pattern of hepatic lesions observed in the outbreak. Liver had smooth and whitish capsular surfaces and a moderate decrease in size. There was moderate irregularity to the cut surface of hepatic parenchyma and pale areas intercalated with red ones. Histologically there was marked periportal fibrosis, marked bile duct proliferation, hepatocellular megalocytosis, focal areas of hepatocellular necrosis, and hemorrhage and veno-occlusive changes. In this second on-site visit, gamma-glutamyltransferase serum activity was determined in 15 affected calves and 13 of them had increased values (26-175 U/L). Seven months after the onset of the outbreak, a third visit was made to the farm when was learned that and additional 27 calves have been affected, 23 of which died within a period of 40 days. At the necropsy of three of these calves the third pattern of hepatic lesions were observed. The liver was decreased in size and markedly firm. The capsular surface was smooth and whitish and the capsular surface

Aspectos epidemiológicos e clínicos dos acidentes ofídicos botrópicos em cães

Snakebites are included in the group of emergencies for domestic animals, and these consultations demand technical knowledge as well as careful clinical evaluation of patients. Because of the importance of this theme and the higher prevalence of snakebites caused by snakes of the genus Bothrops in Rio Grande do Sul state, Brazil, this study aimed to address the epidemiological and clinical aspects of these accidents in dogs in the state, in addition to establishing their incidence. Clinical records of dogs, with a diagnosis of ophidian bothropic accident, assisted at the Toxicological Information Center of Rio Grande do Sul (CIT-RS) were revised from 2014 to 2016. These data were collected at the Toxicological Information Center, Statistics and Evaluation Center, State Secretary of Health. Data on the incidence of accidents and epidemiological and clinical information were obtained for each case. A total of 53 records were revised. In the records that included animal sex (n=49), 53% were female and 46.9% were male. As for animal age (n=47), the dogs ranged from one to 14 years, and most of them (46.9%) were in the 1-4-year age group. Over half of the cases occurred in the rural area (60.7%), and the head and neck were the main venom inoculation sites (76.3%). Diseases were characterized by clinical courses varying from hyperacute (<30 min to 6h), acute (6-24h), to subacute (4-5 days). Severe accidents accounted for 40% of the cases, with edema as the most frequent clinical sign (88.7%) followed by hemorrhagic manifestations (41.5%). Associations of epidemiological and clinical aspects coupled with history of exposure are important characteristics to assist with suspicion and definitive diagnosis of bothropic accidents in dogs.Os acidentes ofídicos se enquadram no grupo de emergências para animais domésticos e esses atendimentos demandam conhecimento técnico, aliado a uma criteriosa avaliação clínica do paciente. Devido à importância do tema e a maior frequência de acidentes ofídicos provocados por serpentes do gênero Bothrops no Rio Grande do Sul, esse estudo teve como objetivo abordar os aspectos epidemiológicos e clínicos desses acidentes em cães nesse estado, além de estabelecer a frequência em que ocorrem. Foram revisados os protocolos de atendimentos clínicos de cães realizados pelo Centro de Informações Toxicológicas do Rio Grande do Sul (CIT-RS) com diagnóstico de acidente ofídico botrópico, entre o período de 2014 e 2016. Esses dados fazem parte do Centro de informação Toxicológica, Secretaria da Saúde, RS, Núcleo de Estatística e Avaliação. Foram obtidos dados relacionados à frequência dos acidentes e informações referentes à epidemiologia e à clínica de cada caso. Totalizaram-se 53 registros de atendimentos. Dos protocolos que informaram o sexo (n=49), 53% corresponderam a fêmeas e 46,9%, a machos. Em relação à idade (n=47), houve uma variação entre um e 14 anos, com maior concentração dos casos entre 1-4 anos (46,9%). Mais da metade dos atendimentos ocorreu em zona rural (60,7%) e a cabeça e o pescoço foram os principais locais de inoculação do veneno botrópico (76,3%). Observou-se uma doença com um curso que variou de hiperagudo (<30 min à 6h), agudo (6-24h) a subagudo (4-5 dias). Acidentes graves representaram 40% dos casos, no qual edema foi o sinal clínico mais frequente (88,7%), seguido por manifestações hemorrágicas (41,5%). A associação dos aspectos epidemiológicos e clínicos, aliados ao histórico de exposição, constituem características importantes que auxiliam na suspeita e no diagnóstico definitivo do acidente botrópico em animais

Aspectos clínicos e patológicos de linfoma bovino afetando a medula espinhal

Clinical and pathological features of bovine lymphoma involving the spinal cord were evaluated through a retrospective study of the necropsy database from 2005 to 2017. Thirty-four cases of bovine lymphoma were found, 24 of which had central nervous system involvement restricted to the spinal cord. All cattle were Holstein cows 2.5-12 years-old (median age, six years-old). The clinical course was 7-21 days, and the main neurological sign was pelvic limb paresis (81.8%). The lymphoma often affected the spinal cord in a multifocal manner. Lumbar segments were the mostly affected sites (23/24), followed by the sacral segments and cauda equina (20/24), cervical (5/24) and thoracic (5/24) segments. Tumors were in the epidural space, peripheral to the pachymeninges (extradural) and between layers of adipose tissue. In addition, two cases had progressive hemorrhagic myelomalacia. Further organs affected included the lymph nodes (100%), abomasum (79.2%), heart (75%) and kidneys (45.8%). Microscopically, all lymphomas had a diffuse pattern, with no meningeal or medullar infiltration. According to the REAL/WHO classification, all these neoplasms were mature B-cell lymphomas. Diffuse large B-cell lymphoma (DLBCL) was observed in 95.8% (23/24) of the cases. The following subtypes were observed in the DLBCL group in descending order: immunoblastic (60.9%, 14/23), centroblastic (26.1%, 6/23), anaplastic (8.7%, 2/23) and T-cell rich (4.3%, 1/23).Os aspectos clínicos e patológicos do linfoma bovino afetando a medula espinhal foram avaliados através de um estudo retrospectivo dos protocolos de necropsia durante o período de 2005-2017. De um total de 34 bovinos com linfoma, 24 apresentaram afecção do sistema nervoso central (SNC) restrito a medula espinhal. Todos os bovinos afetados eram fêmeas, da raça Holandesa, com 2,5 a 12 anos de idade (idade mediana de seis anos). Clinicamente, os casos tiveram uma evolução de sete a 21 dias, com a principal alteração neurológica caracterizada por paresia de membros pélvicos, a qual foi observada em 81,8% dos casos. O linfoma afetou frequentemente a medula espinhal de maneira multifocal. Os segmentos lombares foram os mais envolvidos (23/24), seguidos pelos sacrais e cauda equina (20/24), cervicais (5/24) e torácicos (5/24). Os tumores estavam localizados no espaço epidural, periférica à paquimeninge (extradural) e associada ao tecido adiposo. Em dois casos foi também observada mielomalacia hemorrágica progressiva. Os órgãos acometidos com maior frequência, concomitantemente ao espaço epidural, foram os linfonodos (100%), abomaso (79,2%), coração (75%) e rins (45,8%). Microscopicamente, todos os linfomas exibiam um padrão difuso, sem infiltração em meninges e medula espinhal (extradural). De acordo com a classificação da REAL/WHO, todos esses neoplasmas foram incluídos como linfomas de células B maduras. O linfoma difuso de grandes células B (LDGCB) foi observado em 95,8% (23/24) dos casos. Os subtipos classificados dentro do grupo dos LDGCB’s foram em ordem decrescente: imunoblástico (60,9%; 14/23), centroblástico (26,1%; 6/23), anaplásico (8,7%; 2/23), e rico em células T (4,3%; 1/23)

Bloat in cattle secondary to esophageal obstruction by Citrus limon (sicilian lemon)

Timpanismo ruminal consiste na distensão acentuada do rúmen e retículo, devido a incapacidade do animal em expulsar gases produzidos durante o processo fisiológico da fermentação. O timpanismo pode ser ocasionado de forma primária, por formação de espuma estável, ou secundária, devido a anormalidades funcionais e/ou físicas que interferem na eructação. Nesse trabalho, são descritos os aspectos epidemiológicos, clínicos e anatomopatológicos da ocorrência de timpanismo secundário em bovinos, decorrente da obstrução esofágica aguda por limões sicilianos. Cinco bovinos, de um lote de 210, foram afetados. Os bovinos eram suplementados com resíduo de tangerina (Citrus reticulata) no cocho e na última carga desse subproduto, havia limões sicilianos inteiros misturados ao resíduo. Os cinco animais afetados eram da raça Aberdeen Angus e tinham entre 12-24 meses de idade. Todos apresentaram sinais clínicos caracterizados principalmente por mucosas cianóticas, grave timpanismo, desconforto abdominal, acentuada dispneia e taquicardia, atonia ruminal, desidratação, decúbito e morte. O curso clínico variou entre 24 a 48 horas. Na necropsia, os cinco bovinos apresentavam grave obstrução esofágica por limões nas porções: cranial (logo após a laringe [1/5]), porção medial (entrada do tórax [1/5]) e final (próximo ao cárdia [3/5]). Nas áreas de oclusão, observou-se extensa necrose e ulceração da mucosa esofágica. O conteúdo ruminal dos bovinos estava seco e misturado com limões inteiros. No esôfago de dois animais havia linha de timpanismo. As lesões histológicas eram visualizadas principalmente no esôfago, na região da obstrução, onde se evidenciaram alterações degenerativas, necróticas e ulcerativas acentuadas no revestimento epitelial.Ruminal bloat (acute timpany) in ruminants is a marked rumenreticular distension which results from more gas being produced during the physiologic process of fermentation than is eliminated by eructation. This condition may present itself as either primary timpany due to the formation of stable foam or secondary timpany resulting from functional and/or physical disturbances compromising eructation. This paper describes the epidemiological, clinical, and anatomopathological aspects of acute timpany in cattle secondary to esophageal obstruction by sicilian lemons. Five out of a herd of 210 cattle were affected. Cattle were supplemented with tangerine (Citrus reticulata) residues in a trough. In the last batch of this feed there were whole sicilian lemons mixed with the tangerine residue. The five affected cattle were 12-24 month-old Aberdeen-Angus. All of the five presented clinical signs characterized mainly by cyanotic mucous membranes, severe timpany, abdominal discomfort, marked dyspnea and tachycardia, ruminal atony, dehydration, recumbence and death. Clinical course lasted from 24 to 48 hours. Necropsy findings in the five affected cattle were similar and included complete esophageal obstruction by lemons in the cranial esophagus (immediately cranial to the larynx [1/5]) medial esophagus (at the thoracic inlet [1/5]) and caudal esophagus (close to the cardia [3/5]). At the occluded sites the esophageal mucosa was necrotic and ulcerated. Ruminal content was dried and admixed with whole lemons. In the esophagus o two affected bovine a bloat line was observed. Histological lesions were observed mainly in the esophagus at the sites of obstruction and consisted of marked degenerative, necrotic and ulcerative changes in the esophageal mucosal epithelium

Lily poisoning in domestic cats

Background: Cases of plant intoxication in small animals are observed frequently in the domestic environment, mainly because most dogs and cats live in households and occasionally have access to streets and rural areas. Among such toxic agents, ornamental plants of the genus Lilium and Hemerocallis, which are potentially nephrotoxic to the feline species, are highlighted. Affected cats start presenting clinical signs 1-6 h after plant ingestion. Renal failure takes place in 12-72 h, and death may occur in an interval ranging from three to seven days. The objective of this article is to describe the epidemiological, clinical and pathological findings of lily (Lilium sp.) poisoning in two cats. Case: The aspects of lily poisoning in two cats are described (cat #1 and cat #2). Cat #1 was a 3-year-old, mixed breed female cat, which presented a clinical history of anorexia, apathy, drooling, vomiting and polydipsia. Serum biochemical analysis revealed creatinine elevation (21.2 mg/dL), as well as hyperphosphatemia (19 mg/dL). Seventy-two h after the onset of clinical signs, renal failure progressed to anuria, followed by death. The second animal of this report (cat #2) was a 2-year-old, mixed-breed male cat. The animal was found dead by the owner without displaying any previous clinical signs. Cats #1 and #2 ingested leaves of lily, which were present in their households as ornamental plants. At necropsy, the kidneys of both cats presented mild enlargement. Moderate perirenal edema was also noted. Cat #1 showed morphologic extrarenal uremic lesions, characterized by ulcers in the oral mucosa and in the margin of the tongue ventral surface. Microscopic lesions observed in both cases were similar and compatible with acute toxic nephropathy. Histologically, severe epithelial cell degeneration and necrosis of proximal and distal convoluted tubules were noted. Other renal microscopic findings included hyaline and granular casts, tubule regeneration and occasional birefringent oxalate crystals. Cat #1 also presented moderate white matter vacuolation in the telencephalon and cerebellum. Discussion: The epidemiologic, clinical and pathological findings reported in the present study are similar to previous descriptions of lily poisoning in cats. Lily poisoning has been described in both males and females, without breed and age predisposition, similarly to what has been found in the present study. Kidney metabolite excretion, including the elimination of molecules such as creatinine, urea, and phosphorus is usually compromised in these cases, which was noted in cat #1. The same animal showed extrarenal manifestations of renal failure, leading to a clinical presentation of uremic syndrome, which is not frequent in these intoxications. Animals intoxicated by lily usually die from renal failure and anuria. In most cases, lesions are restricted to the kidneys. In the reported cases, the microscopical lesions consisted of tubule epithelial cells degenerative changes and necrosis. Acute lily intoxication in cats must be differentiated from other conditions, such as intoxications due to aminoglycoside antibiotics, heavy metals, nonsteroidal anti-inflammatory drugs, antifungal agents, chemotherapeutic drugs, and ethylene glycol. The knowledge regarding the toxic potential of ornamental plants is fundamental in order to prevent such events of intoxication, as well as to reach the final diagnosis. Epidemiological, clinical and pathological findings were essential to conclude the final diagnosis

Pet pyometra : correlating bacteria pathogenicity to endometrial histological changes

Pyometra is a life-threatening infectious disease that frequently affects bitches and queens. Although histopathological patterns of pyometra have been extensively explored, the microbiological aspects, such as bacteria pathogenicity, have not been correlated to microscopy endometrial lesions so far. In this study, these two pathological aspects of pyometra were analysed and correlated. Uterus fragments and intrauterine content samples were collected from pets diagnosed with pyometra (30) and submitted to histopathology analysis and bacterial culture, respectively. The degree of endometrial histopathological lesions in pyometra cases were classified as mild, moderate and severe. Thirty different bacteria isolates were identified from intrauterine content culture. Escherichia coli(E. coli) was pure isolated in 57.7% and highly related to severe endometrial lesions. Immunohistochemistry assay revealed the adhesion and invasion of this bacteria agent to the injured endometrium. Virulence aspects of these E. coli strains were explored, demonstrating biofilm formation ability and a set of virulence genes in most isolates. These results support the adaptive genetic and phenotypic advantages of E. coli for uterus infection, and justify the high frequency of this agent involved in pyometra cases

Surto de neuropatia tardia induzida por organofosforados em búfalos

Forty 1-2-y-old water buffaloes were simultaneously treated with trichlorfon and chlorpyrifos products in the recommended dose for cattle. After a week, 19 animals started presenting clinical signs characterized by apathy, diarrhea, aggressiveness, dehydration, and motor incoordination, followed by flaccid paralysis and permanent lateral recumbency. All affected buffaloes died after a clinical course of 1–4 days. Reduction of serum cholinesterase activity in three cases was indicative of significant exposure to organophosphorus compounds (OPs). Pathological examination of three buffaloes revealed no gross and histological lesions. By thin layer chromatography, chlorpyrifos residues and trace of trichlorfon residues were detected in fresh tissue samples. The epidemiological, clinical, pathological, and toxicological findings were highly compatible with OPs-induced delayed neurotoxicity, a neurological manifestation rarely described in domestic animals.Quarenta búfalos foram simultaneamente tratados com clorpirifós e triclorfom na dose recomendada para bovinos. Após uma semana, 19 animais apresentaram sinais clínicos caracterizados por apatia, diarreia, agressividade, desidratação e incoordenação motora, seguidos por paralisia flácida e decúbito lateral permanente. Todos os búfalos afetados morreram após um curso clínico de 1–4 dias. Redução da atividade da colinesterase sérica em três casos foi indicativa de exposição significativa a organofosforados (OPs). O exame patológico de três búfalos não revelou lesões macroscópicas e histológicas. Por cromatografia em camada delgada, resíduos de clorpirifós e traços de resíduos de triclorfon foram detectados em amostras de tecidos frescos. Os achados epidemiológicos, clínicos, patológicos e toxicológicos foram compatíveis com neuropatia tardia induzida por OPs, uma manifestação neurológica raramente descrita em animais domésticos

Lesões parasitárias atípicas em bovinos de abatedouro no sul do Brasil

In this study, we described the morphological features and unusual presentations of hydatidosis, fasciolosis, and eosinophilic myositis caused by Sarcocystis species diagnosed at the slaughterhouse lines. Twenty-seven samples of atypical parasitic lesions from distinct cattle were evaluated, of which 12 corresponded to hydatidosis, 11 to fasciolosis, and 4 to eosinophilic sarcocystosis. Hydatid cysts were observed mainly in the heart, with all cases involving the left ventricle. Fasciolosis lesions involved mainly the lungs, and were characterized by a focal nodular elevated area involving the edges of the lobes. Intralesional trematodes were observed in three cases. Sarcocystosis lesions were observed in four cases, and lesions were primarily located in the skeletal and cardiac muscles. Grossly, they presented as focal or focally extensive streaks, patches, or numerous nodules that were greenish to mildly yellowish. Histologically, all the cases had intralesional ruptured cysts of Sarcocystis that were associated with severe eosinophilic myositis and myocarditis. Parasitic lesions in atypical locations and/or with aberrant responses should be promptly identified because it may mistakenly diagnosed as other potentially zoonotic diseases, such as cysticercosis and tuberculosis.No presente estudo, são descritas as características morfológicas e as apresentações incomuns das lesões parasitárias de hidatidose, fasciolose e miosite eosinofílica por Sarcocystis spp., diagnosticadas nas linhas de abate. Foram analisadas 27 amostras de diferentes bovinos, das quais 12 correspondiam a casos de hidatidose, 11 de fasciolose e 4 de sarcocistose eosinofílica. Os cistos hidáticos foram observados predominantemente no coração, todos com localização no ventrículo esquerdo. As lesões de fasciolose envolveram principalmente os pulmões e eram caracterizadas por áreas nodulares e elevadas nos bordos dos lobos pulmonares. Trematódeos intralesionais estavam presentes em três casos. Lesões de sarcocistose foram observadas em quatro casos, com localização nos músculos esquelético e cardíaco. Macroscopicamente, observaram-se listras, manchas ou numerosos nódulos de coloração esverdeada a discretamente amarelada. Histologicamente, todos os casos apresentaram cistos intralesionais de Sarcocystis spp. rompidos e degenerados, associados à acentuada miosite e miocardite eosinofílica. A identificação das lesões parasitárias em locais poucos frequentes é de extrema importância, pois podem constituir diagnósticos diferencias de enfermidades zoonóticas, como cisticercose e tuberculose

Enterites e tiflocolites parasitárias fatais em equinos no sul do Brasil

Diseases related to the alimentary system are the main cause of death in horses. This retrospective study aimed to describe the pathological findings of fatal parasite-induced enteritis and typhlocolitis caused by cyathostominae, Eimeria leuckarti, Balantidium coli, and Strongyloides westeri in horses. The records of parasite-induced intestinal lesions in horses necropsied in Southern Brazil between 2005 and 2017 were reviewed. Ten horses had fatal parasitic enteritis and/or typhlocolitis, and the main causes were: cyathostominae typhlocolitis (6/10), E. leuckarti enteritis (1/10), S. westeri enteritis (1/10), B. coli colitis related to cyathostominae (1/10), and infection by multiple agents (1/10). Cyathostominae typhlocolitis showed marked mucosal thickening, with multifocal elevated nodules containing tangled filiform parasites. Microscopic examination revealed that the mucosa and submucosa had encysted parasitic structures surrounded by eosinophilic and granulomatous inflammation. E. leuckarti enteritis was microscopically characterized by macrogamonts, microgamonts, and oocysts inside the host cells. S. westeri enteritis showed microscopic atrophy of the villi with numerous mucosal encysted parasitic structures. B. coli typhlocolitis showed severe diffuse mucosal reddening, with microscopic superficial mucosal necrosis associated with multiple protozoan trophozoites. Fatal parasite-induced enteritis and typhlocolitis are important causes of death in horses in Southern Brazil.Doenças relacionadas ao sistema alimentar são as principais causas de morte em equinos. Esse estudo teve o objetivo de descrever aspectos patológicos de enterites e tiflocolites parasitárias fatais por ciatostomíneos, Eimeria leuckarti, Balantidium coli e Strongyloides westeri, em equinos. Foi revisado o banco de dados de lesões intestinais parasitárias em equinos necropsiados de 2005 a 2017, no Sul do Brasil. Dez equinos apresentaram enterite e/ou tiflocolite parasitária fatal, e as principais foram: tiflocolite por ciatostomíneos (6/10), enterite por E. leuckarti (1/10), enterite por S. westeri (1/10), colite por B. coli com ciatostomíneos (1/10), e infecção por múltiplos agentes (1/10). A tiflocolite por ciatostomíneos exibia acentuado espessamento da mucosa, com nódulos multifocais elevados contendo parasitas filiformes. Microscopicamente, a mucosa e submucosa apresentavam estruturas parasitárias encistadas envoltas por inflamação eosinofílica e granulomatosa. A enterite por E. leuckarti era caracterizada microscopicamente por macrogamontes, microgamontes e oocistos no interior de células do hospedeiro. Microscopicamente, a enterite por S. westeri apresentava atrofia de vilosidades com numerosas estruturas parasitárias encistadas na mucosa. A tiflocolite por B. coli exibia avermelhamento acentuado difuso da mucosa, e microscopicamente necrose superficial associada a múltiplos trofozoítos protozoáricos. Enterites e tiflocolites fatais parasitárias são importantes causas de morte em equinos no Sul do Brasil