Poisoning by Senecio brasiliensis in Horses in Northern Rio Grande do Sul

Background: In various regions of Brazil, horses and cattle are considered the most susceptible animals to plant poisoning. The plants of the genus Senecio are the most important in Rio Grande do Sul because they have the active principle known as the pyrrolizidine alkaloid. Its diagnosis is made through epidemiology, clinical signs and histopathological analysis, either of the tissues obtained by biopsy or necropsy. The objective of this study was to report and characterize the epidemiological, clinical and anatomopathological findings of three cases of natural poisoning by Senecio brasiliensis in horses assisted at the Hospital Veterinário (HV) of the Universidade de Passo Fundo (UPF).Cases: Three traction horses, two males and one female, were admitted at the HV-UPF for clinical care. The animals were presenting anorexia, weight loss, dysmetria, proprioceptive deficit and signs suggestive of colic. The epidemiological study revealed that the sites where these animals were located were infested by Senecio brasiliensis. The support therapy used for equine colic in all three cases was unsuccessful. One of the animals died and the other two were euthanized, all three of them being reffered for necropsy. The post-mortem findings were mainly found in the liver, which showed accentuation of the lobular pattern and the appearance of nutmeg. During necropsy, fragments of organs from thoracic and abdominal cavities and central nervous system were collected and fixed in 10% buffered formalin. Subsequently, the samples were processed chemically, submitted to cuts of five micrometers of thickness and stained with hematoxylin and eosin for microscopic analysis. Microscopically, the liver of all three horses presented megalocytosis, fibrosis and bile ducts hyperplasia. In the central nervous system, spongiosis and the presence of Alzheimer type II astrocytes were observed. Thus, through the association of information, the diagnosis of poisoning by Senecio brasiliensis was achieved.Discussion: The diagnosis of natural poisoning by Senecio brasiliensis was obtained through the epidemiological survey that showed S. brasiliensis in pastures where all three horses were allocated.  Cases of intoxication by S. brasieliensis in cattle are more frequent than in equines, although both species are considered the most susceptible. In horses, the main clinical manifestations observed include neurological disorders, apathy, anorexia, dysphagia, weight loss, subcutaneous edema and icterus. The clinical signs presented by the equines suggested initial signs of colic syndrome, although anorexia, weight loss, dysmetria and proprioceptive deficit are commonly observed in pyrrolizidine alkaloid poisoning in the liver, both in cattle and horses. The pyrrolizidine alkaloids present in the genus Senecio that become toxic when biotransformed in the liver into a pyrrholic form highly reactive that inhibits cell mitosis and leads to the onset of megalocytosis, cell death and liver fibrosis. The necropsy findings and histopathology were characteristic of poisoning in equines, since the predominant macroscopic lesions in the liver were hepatomegaly and accentuation of lobular pattern, whereas microscopically, there was a predominance of hepatic fibrosis, megalocytosis, spongiosis and the incidence of Alzheimer's type II astrocytes in the brain. These lesions are observed both in natural and in experimental cases of poisoning in horses. Thus, through the ante-mortem and complete post-mortem evaluation of the three equines, it was possible to establish the occurrence of natural poisoning by Senecio brasiliensis in Northern Rio Grande do Sul, as well as to characterize the epidemiological, clinical and anatomopathological findings of poisoning in this species

Anatomopathological and immunohistochemical characterization of a case of granulomatous meningoencephalitis in a bovine with systemic tuberculosis / Caracterização anatomopatológica e imuno-histoquímica de um caso de meningite granulomatosa em bovino com tuberculose sistêmica

A two-year-old male bovine of Aberdeen Angus breed with anorexia, weight loss, and apathy was reported for necropsy, being diagnosed with systemic tuberculosis and tuberculoid meningitis lesions. Bovine tuberculosis was observed and confirmed through the necropsy of granulomatous lesions, mainly in the lungs and regional lymph nodes; specific staining for alcohol-acid resistant bacilli and immunohistochemistry were also performed. It should be noted that bovine tuberculosis is a zoonotic disease, with mandatory notification, caused by Mycobacterium bovis. In most cases, it has nonspecific clinical symptoms, such as respiratory signs, weight loss, and lymphadenopathy. In rare cases, alterations in the central nervous system occur. Therefore, this study aimed to report a case of granulomatous meningitis in a bovine with systemic tuberculosis through the characterization of its anatomicopathological and immunohistochemical aspects

Ventricular septal defect in sheep - case report / Defeito de septo interventricular em ovino - relato de caso

A 1-month-old uncastrated Ile de France male sheep was diagnosed with an opening in the left interventricular septal. The malformation was evidenced and confirmed through necropsy and observations of systemic histological lesions related to congenital heart disease, especially in the liver, lungs, and heart. Depending on the severity of the defect, the connection promoting free blood transit between the two heart ventricles can be associated with a series of clinical signs culminating in the animal's death. The etiology of congenital malformations in ruminants can be nutritional, toxic, hereditary, or infectious. However, these anomalies are infrequent in sheep; thus, their most common causes are undetermined. The present report describes macro- and microscopic findings related to this congenital malformation in a lamb

Spontaneous poisoning in sheep caused by pseudofruits of Hovenia dulcis (japanese grape): Intoxicação espontânea em ovinos causada por pseudofrutos de Hovenia dulcis (uva japonesa)

An outbreak of spontaneous intoxication by the pseudofruits of the japanese grape (Hovenia dulcis) was observed in a flock of 270 sheep in Rio Grande do Sul, Brazil, resulting in the death of nine animals. The clinical picture was characterized by digestive, nervous, and respiratory alterations with progression to death after 15 to 48 hours. The main microscopic findings were hepatic necrosis, necrosis of the rumen and abomasum mucosa, pulmonary edema and atelectasis, kidney degeneration, cerebral spongiosis, and vacuolization of Purkinje neurons. Hovenia dulcis is wide spread in Brazil, especially in the south of the country. However, this is the first report of spontaneous poisoning in sheep caused by its pseudofruits

Metastatic Vulvar Squamous Cell Carcinoma in a Mare

Background: Squamous cell carcinoma (SCC) is a common cutaneous neoplasm in horses, which mainly affects the external genitalia, oral cavity, and periocular region. The development of SCC metastases is rare in these animals, and the most common occurrence is a marked local infiltration. Exposure to ultraviolet rays and skin depigmentation are the main etiological factors of SCC. Definitive diagnosis of the neoplasm is performed through histological examination of lesions. The present report describes the clinical, anatomopathological, and immunohistochemical (IHC) aspects of a case of metastatic SCC, with the vulva as the primary site in a mare. Case: A 17-year-old mare, mixed breed, was referred to the Veterinary Hospital of the Universidade de Passo Fundo (UPF), with history of areas of depigmented skin (pinto coat), and  clinical history of anorexia, frequent episodes of colic, and recumbency. During clinical evaluation, heart rate (68 bpm), rectal temperature (38.4ºC), and respiratory rate (48 mpm) were elevated, and the oral mucosa was pale. The mare also had an ulcerated tumor mass involving the vulva, which extended to the inguinal region and involved the mammary gland. A cytological aspirate of the vulvar tumor was performed, in which no neoplastic cells were found. Next, a biopsy of 2 distinct areas of the vulva was performed. The material was sent for anatomopathological examination, which showed markedly pleomorphic malignant squamous cells, with individual keratinization and high mitotic index, organized in trabeculae with rare keratin pearl-like formations. The exam allowed the diagnosis of SCC Grade II. Due to the poor prognosis and high cost of treatment, the owner consented to euthanasia and necropsy examination. During necropsy, the vulvar tumor mass was grayish, firm to hard, infiltrative, and had friable areas. Tumor foci suggestive of metastasis were also observed in inguinal, mesenteric, mediastinal and renal lymph nodes, adrenal glands, lung, pericardium, medullary canal, intercostal muscles, right 15th rib, and tissue surrounding the azygos vein. Samples from all organs were collected for anatomopathological examination. Diagnosis of metastatic vulvar SCC was confirmed through histological and IHC studies, which evaluated the expression of cytokeratins (AE1/AE3), as well as the proliferative activity of neoplastic cells through the PCNA marker. Discussion: The diagnosis of metastatic SCC was obtained through the observed clinical, necroscopic, histological, and IHC characteristics. This neoplasm usually appears in depigmented regions exposed to ultraviolet light, and older animals are more likely to be affected. The mare in the present case had areas of depigmented skin (pinto coat). The animal was kept in a paddock outdoor and exposed to constant solar radiation. Although rare in horses, manifestation of anorexia, progressive weight loss, and frequent colic episodes and recumbency may be closely related to the multiple sites of metastasis in the present case. The main histological findings of the neoplasm were the dense proliferation of malignant squamous cells with individual keratinization, arranged in a trabecular pattern and with rare formations of keratin pearls, in line with previous studies. During IHC evaluation, the neoplastic cells showed expression of cytokeratins (AE1/AE3), as well as high proliferative activity evidenced by the PCNA marker. Given this background, the present report describes the clinical, anatomopathological, and IHC aspects of a case of metastatic SCC with a primary site in the vulva of a mare. Keywords: equine, genital neoplasm, tumor embolism, squamous cell carcinoma, metastasis, immunohistochemistry

Eugenia pyriformis ('uvaia') intoxication of sheep / Intoxicação por Eugenia pyriformis ('uvaia') em ovinos

This study describes the clinical and pathological picture of a disease followed by death in sheep raised for subsistence, characterized by difficulty in locomotion, sternal decubitus, severe dyspnea, opisthotonos, and pedaling movements, followed by death. The disease occurred in February 2020 in the northern state of Rio Grande do Sul, Brazil, due to the consumption of the fruits of Eugenia pyriformis ('uvaia'). All sheep that became ill later died, resulting in morbidity of 68.75% and mortality of 100%. An autopsy revealed the presence of E. pyriformis fruits with or without seeds in the rumen, in addition to the diet provided to the animals. The main histological findings consisted of edema and perivascular cuffs in the frontal telencephalon, nephrosis and glomerular necrosis, in addition to glomerulosclerosis. One sheep had heightened urea and creatinine and lower levels of non-protein thiols. Deaths ceased once animals were prevented from accessing E. pyriformis. These findings confirm that this plant was responsible for the deaths of the animals and point to the possibility of E. pyriformis having neurotoxic and nephrotoxic action on sheep

Infecção multissistêmica por Dipetalonema spp. em um macaco-prego (Sapajus nigritus)

O macaco-prego (Sapajus nigritus) é um dos primatas que compõem a fauna silvestre do Rio Grande do Sul. Assim como outros animais silvestres, os primatas padecem de doenças infecciosas veiculadas por insetos, entre as quais, as filarioses. Este relato apresenta os aspectos anatomopatológicos de uma infecção multissistêmica por Dipetalonema spp. em um macaco-prego, fêmea, adulta, de origem silvestre, resgatado junto a uma rodovia do Norte do Estado do Rio Grande do Sul pelo serviço de policiamento rodoviário e conduzida para atendimento. Na avaliação clínica observaram-se nistagmo e movimentos involuntários da cabeça, estado semi-comatoso, hipertermia (38,7ºC), hipovolemia, múltiplas escoriações e lacerações cutâneas profundas abrangendo camadas musculares. O paciente foi hospitalizado e medicado, mas apresentou piora do quadro clínico, que evoluiu a óbito. Na necropsia, os principais achados foram na cavidade peritoneal, onde observaram-se acúmulo de líquido seroso amarelado, marcada formação de aderências fibrinosas e numerosos parasitas nematódeos livres na cavidade. Histologicamente foram observadas microfilárias no lúmen de vasos sanguíneos do pulmão, fígado, coração, rins, baço, intestinos delgado e grosso, e cérebro. Também foram constatadas peritonite, pneumonia e bronquiolite associadas à nematódeos, danos hepáticos e microgliose cerebral com satelitose, neuronofagia e malácia hemorrágica. Microfilarias e filarídeos adultos foram submetidos à identificação morfométrica e caracterizados como pertencentes ao gênero Dipetalonema. Assim, foi concluído tratar-se de um caso de infecção multissistêmica por Dipetalonema spp. Palavras-chave: animal silvestre; dipetalonemose; microfilária; parasita; macac

Abordagem “One Health” na toxoplasmose: soroprevalência de Toxoplasma gondii em suínos

O objetivo desse estudo foi avaliar por imunofluorescência indireta (IFI) a soroprevalência de Toxoplasma gondii em suínos, identificar por PCR a presença de T. gondii em linguiças suínas defumadas e relacionar a epidemiologia e a transmissão de toxoplasmose aos humanos através de uma abordagem “One Health” integrando a saúde humana, a saúde animal e o consumo de alimentos seguros. Foram avaliadas 50 amostras de soro sanguíneo de suínos e 18 amostras de linguiças suínas defumadas. No teste de imunofluorescência indireta (IFI) 8% dos animais foram positivos para T. gondii e no PCR todas as amostras foram negativas. Apesar dos resultados negativos no PCR, a presença de suínos soropositivos para T. gondii encaminhados ao abate e posterior industrialização da carcaça demonstra potencial risco à saúde pública, seja no consumo inadequado da carne in natura suína ou em subprodutos cárneos, reforçando assim, a abordagem “One Health” na toxoplasmose e sua contribuição na epidemiologia e transmissão de T. gondii aos humanos

Mastocitoma intranasal unilateral em canino com metástase em linfonodo submandibular

Background: Mast cell tumors (MCTs) are neoplasms originating from mast cells, which can be well or poorly  differentiated. They are considered the most commonly diagnosed malignant cutaneous neoplasm in dogs; however, intranasal forms are still little reported. Thus, this study seeks to report a case of unilateral intranasal MCT exhibiting submandibular lymph node metastasis.Case: A 11-year-old-and-4-month-old dog of undefined breed (UB), weighing 41 kg, was referred to the Veterinary Medical Teaching Hospital of the University of Passo Fundo (UPF), in the state of Rio Grande do Sul, Brazil. Presenting a clinical history of bilateral purulent nasal secretion, accompanied by sneezing in the two months prior to admission, in addition to vomiting and diarrhea. Auxiliary tests were requested, including skull X-ray, cytology of the nasal cavity with a swab, and collection of material from the submandibular lymph node directly through cytology with a needle. Cytological findings from the right nasal cavity were consistent with mast cell tumors (MCTs). Cytological analysis of the left nasal cavity was compatible with dysplasia/cellular reactivity. A heterogeneous population of cells was detected on cytology of the right submandibular lymph node. These findings were consistent with MCT lymph node metastasis. Skull radiographyshowed an increase in both opacity and soft tissue extension, surpassing the palate, from the canine tooth through the caudal region of the maxillary sinuses to the last molar, without bone destruction. The dog was then admitted for an abdominal ultrasound, which showed no changes in the spleen or liver. The leukocyte count showed mild lymphopenia and the presence of reactive lymphocytes. Through the buffy coat, the presence of rare round cells, compatible with circulating mast cells, was detected. Due to the biological behavior of the neoplasm and its anatomical location, the established therapy was based on the use of vinblastine and prednisolone. The patient did not show any clinical improvements. In a joint decision with the patient’s guardian, the dog was euthanized.Discussion: Intranasal MCTs commonly present progressive and intermittent unilateral epitaxis, mucopurulent nasal discharge, dyspnea, and ocular discharge. Several anatomical sites were associated with more aggressive neoplastic phenotypes; those with an unfavorable prognosis were mainly those present in the oral and intranasal mucosa. Cytopathological examination is considered a highly sensitive method for the diagnosis of MCTs. Metastases are present in more than 90% of mucosal MCTs, usually affecting regional lymph nodes and associated with a poor prognosis. Radiography is considered a useful test in determining the size and location of tumors in the nasal cavity. Chemotherapy plays an important role in the treatment, especially in cases like the one described in this report, in which surgical excision is not possible due to the anatomical location of the neoplasm. Intranasal MCTs are uncommon in dogs. In this case, he presented aggressive, metastatic behavior and a poor response to antineoplastic therapy. Furthermore, due to the location of these tumors, they may be clinically similar to a number of other upper respiratory tract diseases, posing a diagnostic challenge. Therefore, it is essential that the search for differential diagnoses be carried out through auxiliary tests, such as cytology and imaging. Keywords: neoplasm, cytology, diagnosis, chemotherapy

Mastocitoma intranasal unilateral em canino com metástase em linfonodo submandibular

Background: Mast cell tumors (MCTs) are neoplasms originating from mast cells, which can be well or poorly  differentiated. They are considered the most commonly diagnosed malignant cutaneous neoplasm in dogs; however, intranasal forms are still little reported. Thus, this study seeks to report a case of unilateral intranasal MCT exhibiting submandibular lymph node metastasis.Case: A 11-year-old-and-4-month-old dog of undefined breed (UB), weighing 41 kg, was referred to the Veterinary Medical Teaching Hospital of the University of Passo Fundo (UPF), in the state of Rio Grande do Sul, Brazil. Presenting a clinical history of bilateral purulent nasal secretion, accompanied by sneezing in the two months prior to admission, in addition to vomiting and diarrhea. Auxiliary tests were requested, including skull X-ray, cytology of the nasal cavity with a swab, and collection of material from the submandibular lymph node directly through cytology with a needle. Cytological findings from the right nasal cavity were consistent with mast cell tumors (MCTs). Cytological analysis of the left nasal cavity was compatible with dysplasia/cellular reactivity. A heterogeneous population of cells was detected on cytology of the right submandibular lymph node. These findings were consistent with MCT lymph node metastasis. Skull radiographyshowed an increase in both opacity and soft tissue extension, surpassing the palate, from the canine tooth through the caudal region of the maxillary sinuses to the last molar, without bone destruction. The dog was then admitted for an abdominal ultrasound, which showed no changes in the spleen or liver. The leukocyte count showed mild lymphopenia and the presence of reactive lymphocytes. Through the buffy coat, the presence of rare round cells, compatible with circulating mast cells, was detected. Due to the biological behavior of the neoplasm and its anatomical location, the established therapy was based on the use of vinblastine and prednisolone. The patient did not show any clinical improvements. In a joint decision with the patient’s guardian, the dog was euthanized.Discussion: Intranasal MCTs commonly present progressive and intermittent unilateral epitaxis, mucopurulent nasal discharge, dyspnea, and ocular discharge. Several anatomical sites were associated with more aggressive neoplastic phenotypes; those with an unfavorable prognosis were mainly those present in the oral and intranasal mucosa. Cytopathological examination is considered a highly sensitive method for the diagnosis of MCTs. Metastases are present in more than 90% of mucosal MCTs, usually affecting regional lymph nodes and associated with a poor prognosis. Radiography is considered a useful test in determining the size and location of tumors in the nasal cavity. Chemotherapy plays an important role in the treatment, especially in cases like the one described in this report, in which surgical excision is not possible due to the anatomical location of the neoplasm. Intranasal MCTs are uncommon in dogs. In this case, he presented aggressive, metastatic behavior and a poor response to antineoplastic therapy. Furthermore, due to the location of these tumors, they may be clinically similar to a number of other upper respiratory tract diseases, posing a diagnostic challenge. Therefore, it is essential that the search for differential diagnoses be carried out through auxiliary tests, such as cytology and imaging. Keywords: neoplasm, cytology, diagnosis, chemotherapy