Ticiana N. França

Intoxicação experimental por monofluoroacetato de sódio em bovinos: aspectos clínicos e patológicos

Sodium monofluoroacetate (MF) was identified, by cromatography, in three of the 12 plants that cause sudden death in cattle in Brazil, including Palicourea marcgravii, the most important plant of this group. A special kind of hydropic-vacuolar degeneration (HVD) of the distal convoluted uriniferous tubules was considered typical for the poisoning by some authors. The objective of this study was to verify if the ingestion of MF causes similar clinical signs and lesion in cattle poisoned by plants that cause sudden death. Six cows received orally 0.5 and 1.0mg/kg of M diluted in 50mL of distilled water. Clinically the animals presented tachycardia, engorgement and positive pulse of the jugular vein, abdominal breathing, swaying gait, subtle unbalance, and recumbency with head placed the on the flank. In the agonal phase all the animals in lateral recumbence presented muscular fasciculation, tonic contraction, peddling movements, opisthotonus, nystagmus, and died between 2 and 14 minutes. At postmortem examination, the heart auricles, jugular and pulmonary veins were moderately distended and engorged with blood. Slight to moderate edema of the subserosa was seen around the gall bladder and the duodenum near to the pancreas. At light microscopy, HVD associated with nuclear picnosis of the epithelial cells of the distal convoluted uriniferous tubules was present in all animals. Ultrastructurally, the cell lesion represents formation of cytosolic vacuoles, likely due to accumulation of water. Coagulation necrosis of individual or groups of hepatocytes and slight hepatic congestion secondary to the venous stasis were also observed. Hydropic-vacuolar degeneration has been observed in cases of poisoning by many substances, which cause acute tubular nephrosis, however not restricted to the distal renal tubules and without nuclear picnosis. This study demonstrates that the HVD in the kidney can be caused by MF and, in analogy, the compound should be considered responsible for the death of cattle that ingest toxic plants which cause sudden death in Brazil. Our results can be supportive to studies that will focus on the degradation of MF by rumen bacteria, what might have economic implications, as at least 500.000 cattle die annually by sudden death causing toxic plants in Brazil.

Intoxicação por antibióticos ionóforos em animais

The therapeutic use of ionophores in veterinary medicine has grown in the last years, with resultant increase in the risk of poisoning in animals. Ionophores are used as food additives as coccidiostacts in several animal species and growth promoter and bloat prevention in ruminants. The most often used ionophores are monensin, lasalocid, narasin and salinomycin. There is a great variation in the susceptibility to the toxic effect of ionophores in different animal species. Poisoning can occur when the dosage is too high or when not correct doses for a certain animal species are given. Cases of poisoning have been described in sheep, swine, horses, dogs and poultry. For horses ionophores are extremely toxic. The use of ionophores is only safe when used accordingly to the instructions of the manufacturer and especially for each animal species. In this paper the most important data regarding clinical-pathological and pathogenic aspects, and also the conditions in which the poisoning may occur are critically reviewed.

Intoxicação natural por Amaranthus spinosus (Amaranthaceae) em ovinos no Sudeste do Brasil

An outbreak of acute poisoning caused by Amaranthus spinosus is described in ewes of southern Brazil. The clinical signs were characterized by uremic halitosis, loss of ruminal motility, dispnoea and abortion. Grossly in the kidneys there were pale red spots, white streaks extending from cortex to medulla, and congestion. Histologically there was a severe acute tubular nephrosis, dispersed foci of coagulative necrosis in the liver, areas of coagulative necrosis in the myocardium and acute incipient interstitial pneumonia as well as secondary bronchopneumonia. Myocardial coagulative necrosis observed in seven sheep was attributed to hyperkalemia secondary to renal insufficiency. No references to spontaneous A. spinosus poisoning in sheep was found in the literature. Attempt to reproduce the poisoning by administration of the plant to sheep was insuccessful, probably because A. spinosus used was not from fertilized areas.

Enfermidades associadas à intoxicação por selênio em animais

Trough a critical literature review, the main data of selenium poisoning in domestic animals are presented. Epidemiological, clinical, anatomic and histopathological aspects attributed to Alkali Disease, Blind Staggers, acute poisoning and focal symmetrical poliomielomalacia of swine are discussed. The main objective of the paper is to clarify obscure points of selenium poisoning, as well to point out the risks that supplementation with this element can represent.

Avaliação de técnicas de biópsia hepática em ovinos

Due to lack of information about the subject and lack of studies that confront the techniques of liver biopsy in sheep, a comparative study between eight biopsy techniques in this species was developed. In this study, eight crossbred (Santa Ines) ewe lambs (17.95 kg ± 2.71) were used in serial procedures for eight consecutive weeks. Liver samples obtained through six percutaneous techniques and two videolaparoscopic techniques were analyzed. The clinical aspects, clinical pathological findings, hepatic sample weights, histology quality, number of centrilobular veins and portal spaces, and the presence of artifacts in the histology slices were recorded. For the percutaneous techniques, two types of needles were used, modified Menghini (M) and semi-automatic tru-cut (T). They were used in combinations with blind biopsies, guided by ultrasound (US) and monitored by video laparoscopy (VL) biopsies. In the videolaparoscopy procedures, Blakesley biopsy forceps and the method of liver fragment resection by VL were used. No relevant hematological or biochemical alterations were found and the clinical manifestations were slight and transitory. In a general way, the use of US and VL in percutaneous biopsies did not yield a significant improvement in weight and histology quality of the liver samples; however, the videolaparoscopic techniques allowed a wider access to the liver than the percutaneous techniques. The quality of the samples obtained through both VL techniques were equivalent; however, the resection technique enabled the collection of heavier samples, but determined the formation of perihepatic adherences. More difficulty in fragment retrieval, more fluctuation in weight and less quality were found in samples obtained with M needles when compared to T needles.

Surto de Circovirose (síndrome definhante multissistêmica de suínos desmamados) no estado do Rio de Janeiro

The first outbreak of Postweaning Multisystemic Wasting Syndrome (PMWS) in swine, which occurred in southeastern Brazil, in the state of Rio de Janeiro, is described. The disease, which affects mainly weaned about 4 month-old pigs, caused the death of at least 14 animals. The property, where the outbreak occurred, had inadequate sanitary and management conditions. Clinically the disease was characterized by wasting, poor development, cough, tachypnoea, dispnoea, diarrhoea, ataxia, tremors after stimulation, decubitus and convulsions. The course of the disease was acute or subacute. The most important post-mortem findings were enlarged lymphnodes, non-collapsed lungs, with consolidated areas mainly in the cranial lobes. Histological lesions consisted mainly of lymphohistiocytic infiltration with multinucleate giant cells in lymph nodes, spleen, Peyers patches, kidney, lung and liver, depletion or lymphoid hyperplasia, as well as lymphohistiocytic interstitial pneumonia and areas of secondary bronchopneumonia. The diagnosis was established through observations of the symptoms and typical lesions, and was confirmed by immunohistochemical examination and PCR. The objective of this study was to characterize the epidemiological, clinical and pathological aspects of the outbreak of PMWS, because of the severe direct or indirect economical losses caused by the disease to the world pig industry.

Intoxicação acidental por monensina em ovinos no Estado do Rio de Janeiro

An outbreak of monensin poisoning in sheep in the State of Rio de Janeiro is described. From 180 animals, eight died after they had been fed with ration containing the ionophore. The poisoning had a variable course and was clinically characterized by apathy, heart arrhythmia, myoglobinuria, incoordenation, incapacity of getting up, and sternal decubitus; one sheep aborted. The macroscopic lesions consisted of pale areas in the myocardium, hydroperitoneum, hydrothorax, and pulmonary edema. Histopathological examination revealed degenerative-necrotic alterations in heart and skeletal muscles. In the myocardium lesions were more severe and were characterized by multifocal necrosis with substitution of the myofibres by fibrous tissue and interstitial mononuclear infiltration. Proliferation of satellite cells and mononuclear inflammatory reaction in skeletal muscles were also verified. It seems that the exaggerated addition of sodic monensin, eventually associated with improper homogenization of monensin in the ration, was responsible for the excessive ingestion of monensin by some animals.

Spontaneous poisoning by Leucaena leucocephalai in a goat from Rio de Janeiro State, Brazil

Poisoning of a goat by Leucaena leucocephalai (Leg. Mimosoideae) in the State of Rio de Janeiro, Brazil, is described. Fresh leaves of the plant were ingested as the animals main meal for at least 4 months before it developed total alopecia. At necropsy the thyroid was moderately enlarged. Histological examination revealed a decrease in the number of hair follicles (empty or in telogenic phase), vacuolation of keratinocytes of the epidermis and hair follicles, and superficial and follicular hyperkeratosis. Myxedema was found between skeletal and cardiac muscles fibers, in the kidneys, and in the submucosa/muscular layer of the digestive tract. The thyroid follicles were enlarged and filled with copious amounts of colloid (colloidal goiter). Although L. leucocephala is common in several tropical regions, natural poisoning by this plant in goats seems to be rare. It is the first report about spontaneous poisoning in goats by L. leucocephala in Brazil.

Mammary adenocarcinoma in a mare

A non-lactating 17-year-old grey barren Mangalarga Marchador mare was referred to the Large Animal Veterinary Hospital of the Federal Rural University of Rio de Janeiro (UFRRJ), presenting enlargement of the mammary gland. The owner reported that the animal had a lesion in the mammary gland for at least two years, diagnosed and treated as chronic mastitis. Initially only the right gland was involved, presenting ulceration and exudation on the cutaneous surface. After 20 months, the left gland also became affected. The diagnosis of tubulo-papillary adenocarcinoma was based on the typical microscopic lesions. This work shows the importance of the histopathological examination in the differential diagnosis between the neoplasms and the chronic inflammation in the mammary gland of mares, as well as, to show that the cytological examination cannot detect the tumor, in case the puncture is made in areas of secondary infection.

Aspectos toxicológico, clínico-patológico e ultraestrutural das intoxicações iatrogênica e experimental por vitamina D em coelhos

Toxicological, clinic-pathological and ultrastructural aspects of iatrogenic and experimental subcutaneous poisoning in rabbits by vitamin D are described. Clinically the animals showed signs of cardiovascular insufficiency, as ascite and lung edema, hyporexia, anorexia, mucous diarrhoea, loss of weight and apathy. The classical alterations of minera-lization and, occasionally, ossification of the cardiovascular system, as well the lesions of kidneys, lungs, stomach, among other organs, were reproduced by the subcutaneous administration of an oily solution of cholecalciferol (non-activated vitamin D3).