Paula V. Leal

Enterolobium contortisiliquum is a cause of acute ruminal acidosis in sheep

ABSTRACT The ingestion of pods of Enterolobium contortisiliquum is associated with digestive disturbances, photosensitivity and abortion in domestic ruminants. This experiment was designed to test the hypothesis that digestive disturbances in this toxicosis are really caused by acute ruminal acidosis. Three sheep fed large doses (10–15 g/kg/body weight [bw]) of E. contortisiliquum pods developed ruminal acidosis and were treated with sodium bicarbonate to try to control this metabolic disturbance, thus providing additional evidence of the involvement of ruminal acidosis in the pathogenesis of toxicosis. Two of the sheep died, and one recovered after treatment. In the two sheep that developed severe signs of ruminal acidosis, the values of blood lactate were 18 mg/dL and 196.88 mg/dL, indicating metabolic acidosis as the cause of death. Additionally, four sheep developed elevated serum levels of aspartate aminotransferase and gamma glutamyl transferase, indicating that the pods had hepatotoxic effects. Necropsy findings included the accentuation of the hepatic lobular pattern and multiple focally extensive red areas in the rumen mucosa and on the surface of the liver. Repeated ingestion of small doses induced tolerance but did not induce cumulative effects. Histopathologically, the epithelial mucosa of the rumen and reticulum exhibited swollen and vacuolated epithelia with intraepithelial pustules. Focal ulceration of the mucosa was also observed. Multifocal vacuolar degeneration of hepatocytes and scattered individual hepatocellular necrosis were evident in the liver. We concluded that the main clinical manifestation of intoxication by E. contortisiliquum pods in sheep was acute ruminal lactic acidosis and metabolic acidosis. Ingestion of repeated sublethal doses could stimulate proliferation of the ruminal fauna that degrades the sugar present in the pods, and thereby prevent the occurrence of ruminal acidosis. The plant is also hepatotoxic, and no abortions were observed. HIGHLIGHTSThe digestive disturbances in sheep fed the pods of Enterolobium contortisiliquum result from acute ruminal acidosis.Repeated ingestion of sublethal doses of the pods induces tolerance.Enterolobium contortisiliquum pods have no accumulative toxic effect.The pods of Enterolobium contortisiliquum are hepatotoxic.

Ingestion of the pods of Enterolobium contortisiliquum causes hepatogenous photosensitization in cattle

ABSTRACT Enterolobium contortisiliquum (Leg. Mimosoidae) is reported as a poisonous plant related to photosensitization and photodermatitis, digestive disturbs and abortion. To date, the clinical and pathological features of photosensitization has not been reproduced or only reproduced associated with very mild presentations. The objective of this study was to reproduce in cattle the clinicopathological features of photosensitization associated with the ingestion of the pods of E. contortisiliquum. The pods were harvested from a property with a history of an ongoing outbreak of photosensitization and abortion in cattle. Six 24‐month‐old steers were cannulated and used in the experiment, two of them served as negative controls. E. contortisiliquum pods were administered to four steers through ruminal cannula. In the first phase of the experiment, daily doses of 30 g/kg/body weight (bw) and 20 g/kg/bw were administered to Bovines 1 and 2 respectively, for three consecutive days. In the second phase, starting four days after the last daily feeding of the pods, these two bovines were challenged with the same doses of the pods for three consecutive days and another two steers (Bovines 3 and 4) were fed 15 g/kg/bw each for three consecutive days. In the two phases, the steers developed signs compatible with ruminal acidosis which were more severe during the second phase. Three and five days after the administration of the pods, two steers presented photodermatitis characterized by hyperemia and edema on the skin of the dorsum of the neck, of the shaved skin around the cannula, of muzzle and ear. Lesions evolved to dermal necrosis with sloughing and subsequent scar retraction and dermal thickening. Ulceration of mucosae exposed to sunlight was also observed. All the steers which received the pods had significant elevations in the serum activities of gamma‐glutamyl transferase (GGT) and aspartate aminotransferase (AST). The levels of GGT and AST remained elevated for up to 12 days after the administration of the pods was discontinued. Histopathological hepatic changes detected by liver biopsies were hepatocellular swelling and randomly scattered individual hepatocellular necrosis. The current study presents solid experimental evidence that the ingestion of E. contortisiliquum definitely induces the classical lesions of hepatogenous photosensitization in cattle. HIGHLIGHTSThe poisonous by Enterolobium contortisiliquum in cattle causes phosensitization.Photosensitization tends to develop in those bovines that survive the acute phase of gastrointestinal disturbances.The phosensitization is of the hepatogenous type.Hepatotoxic is demonstrable by clinical pathology and liver biopsy.

Estimativas de perdas econômicas causadas por reação granulomatosa local após uso de vacina oleosa contra febre aftosa em bovinos de Mato Grosso do Sul

Lesions caused by excessive reaction to foot and mouth vaccine were observed in 1,815 out of 5,000 cattle slaughtered in a slaughterhouse under federal meat inspection. Such lesions resulted in condemnation of the affect parts of the carcasses in accordance with the Brazilian Federal Meat Inspection Regulations. The affected cattle had been vaccinated on May 2012 and then slaughtered in September of the same year. They were allotted to two groups with 1,500 (Groups 1) and 315 cattle (Group 2). Post vaccination lesions were characterized as salient, firm variable sized nodules multifocally distributed in the musculature of the lateral neck. Pus oozed at the cut surface of these nodules. Samples of 28 cattle were submitted for histopathological examination; main findings were pyogranulomas with central variable-sized clear spaces surrounded by marked infiltrate of viable and dead neutrophils, which were surrounded by epithelioid macrophages with vacuolated cytoplasm and occasional multinucleated giant cell. This inflammatory reaction was walled by abundant connective tissue infiltrated by lymphocytes and plasma cells. Samples of the lesion of six cattle were submitted to bacteriological culture with negative results. When affected carcasses went through dressing, there was an average of 1.8 and 2.0 kg of muscle tissue cut off from the carcasses respectively of Group 1 and 2. Economic losses in the farm of origin of the affected cattle was R

Intoxicação experimental por Simarouba versicolor (Simaroubaceae) em ovinos e indução de resistência ao consumo da planta

20,424.00, considering the price paid by kg of cattle for slaughter at the time of the occurrence. This amount at that time was enough to buy 29.17 weaned calves for fattening. If one considers theses 5,000 cattle vaccinated on the farm as the population at risk, the morbidity rate would be 0.36%. These results indicate that the losses due to vaccine reaction, even with no overt clinical signs, may cause important economic losses.

Experimental poisoning by Vernonia rubricaulis in sheep

Simarouba versicolor St. Hil. is a semideciduous tree belonging to the Simaroubaceae family. An outbreak of poisoning in cattle by shoots of S. versicolor present in the pasture in Mato Grosso do Sul and experimental reproduction of the poisoning was described. This study aimed to verify experimentally whether sheep could be used as a clinical-pathological model in the study of the poisoning caused by S. versicolor, to determine if there develops resistance induced by ingestion of small and repeated doses of the leaves, and if the plant keeps its toxicity when dried. Two experiments were conducted: Experiment 1 with green leaves or dried and powdered leave of S. versicolor, given in single doses of 5g/kg, 5g/kg and 3g/kg to three sheep (Sheep 1, 2 and 3 respectively). Experiment 2 was made with different daily doses of dried and powdered leaves of S. versicolor; to four sheep was given 1.5g/kg, 0.75g/kg, 0.6g/kg and 0.3g/kg, and the positive control (Sheep 4) received 3g/kg. The administration was suspended when the animals showed clinical signs of poisoning. After twelve days of recovery, the surviving sheep were challenged with the same daily dose given previously, to assess the development of resistance. Clinical signs observed in both experiments were characterized by anorexia, congested ocular mucosa, polydipsia, drooling, loose stools which evolved into fetid greenish watery diarrhea, lateral decumbency and death of Sheep 1 to 7. The main histological lesions observed were necrosis of lymphoid tissue (lymph nodes, spleen, Peyers patches) and necrotizing enteritis. With the results it can be concluded that sheep can be used as experimental model for the clinic-pathological aspects of poisoning by S. versicolor. The method used has not shown resistance to the daily consumption of the plant by the sheep, and the leaves kept their toxicity when dried.

Photosensitization in Cattle Caused by Spontaneous and Experimentally Ingestion of Stryphnodendron fissuratum

ABSTRACT In order to evaluate the susceptibility of sheep to V. rubricaulis and to establish the clinical signs, serum biochemistry, and pathological findings, eight sheep were fed varying doses of V. rubricaulis. The onset of clinical signs occurred 6–48 h after the ingestion of V. rubricaulis. Clinical courses lasted 6–56 h after the ingestion of the plant. Serum activities of aspartate aminotransferase, gamma‐glutamyl transferase, and alkaline phosphatase were highly elevated and glucose blood levels were low in affected sheep. Clinical signs consisted of apathy, anorexia, dry muzzle, respiratory distress, abdominal pain, and mushy feces with streaks of blood and mucus. Two sheep had neurological signs including muscle fasciculation, nystagmus, paddling movements, and blindness. Liver necrosis could be detected antemortem through liver biopsy. Five sheep died and three recovered. The liver was affected in all necropsied sheep; it increased in volume and had marked accentuation of the lobular pattern with red, depressed areas intercalated with a pale yellow network. Ascites and hydropericardium were consistent findings. Microscopically, centrilobular to massive coagulative necrosis was observed. Coagulative necrosis was also observed in a few proximal renal tubules. Microscopic lesions were not found in any other organs. The severity of liver lesions was proportional to the dose. Chemical analysis to detect carboxyatractyloside in V. rubricaulis plant material was negative. It is concluded that V. rubricaulis poisoning in sheep is clinically, biochemically, and pathologically characteristic of an acute hepatoxicosis. HighlightsSheep are susceptible to poisoning by Vernonia rubricaulis.Experimental poisoning by Vernonia rubricaulis in sheep causes acute hepatotoxicosis.Hepatotoxicity can be demonstrated antemortem by clinical pathology and liver biopsy.Hepatic lesions are dose‐dependent.

Toxic diseases of bovines from of Mato Grosso do Sul

Background: Stryphnodendron fissuratum is a tree from the Brazilian Cerrado. Its fruit is toxic to cattle and can cause clinical digestive signs, hepatogenous photosensitization, and abortion. Cases of poisoning in cattle, goats and guinea pigs have been experimentally reproduced; however, photosensitization could not be reproduced. The aim of this work was to describe an outbreak of natural poisoning and experimental reproduction in cattle, both with hepatogenous photosensitization. Materials, Methods & Results: Its described and natural outbreak and an experimental poisoning. In the outbreak, three bovines in the acute phase and three in the chronic phase were examined. Blood samples were collected from all of these animals in order to measure serum levels of aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), urea, and creatinine. The first three animals underwent necropsy and histopathological evaluation. The experiment was conducted with two nine-month-old calves that received an oral paste made with crushed S. fissuratum fruits mixed with water. These fruits were collected at a farm at which cattle poisoning cases had occurred. Blood samples were collected in order to measure serum levels of AST, GGT, urea, and creatinine, before plant administration and then daily during the experimental period. Skin biopsies were taken before plant administration and new one after the first signs of skin lesions. The natural outbreak affected 52 of 160 bovine (31 calves and 21 cows) in the lot. Two calves and 14 cows died. Clinical signs consisted of depression, ataxia, incoordination, behavioral changes, decubitus, and death. One animal that died and 36 others that recovered had photodermatitis. Necropsy findings in the animals consisted of bad corporal condition, pale kidneys, evidence of liver lobular pattern, dry rumen contents, and full bladder. In two animals, fruit seeds were found in the rumen, and one animal had ulcers and transmural edema in the abomasum. Microscopically, mild to moderate renal tubular distension, accumulation of proteinaceous material in lumen with mild to moderate swelling, and epithelial necrosis. In the liver, swelling of hepatocytes and moderate bile stasis was detected. Enzymes values in all evaluated bovines were higher than those considered normal for the species. Experimentally, both calves became ill and one died. The clinical signs were apathy, inappetence, wobbling, weight loss, and goosebumps. One of them had jaundice, tearing, photophobia, ear skin detachment, and ulcers at the muzzle, nostrils and ventral face of the tongue. This animal was euthanized in extremis, and the necropsy findings showed generalized jaundice, evidence of increased liver lobular pattern, thick bile, pale kidneys, and esophageal, tongue, and epiglottal ulcers. Microscopically, the lesions were similar to those described during the natural outbreak. The skin biopsy from the calf that recovered showed perivascular edema and mild eosinophilia. Discussion: The diagnosis was made based on clinical signs, necropsy findings, histopathological lesions, and epidemiological analysis. Experimentally, the plant was toxic at the administered doses. Photosensitization was the most common clinical sign during the natural outbreak and until now, has never been experimentally reproduced. Based on histopathological lesions observed in this study, we can consider that is from hepatogenous origin. The results showed that the kidney lesions have an important role during the pathogenesis caused by this poisoning and during disease evolution.