Hepatogenous Photosensitization Research Articles

Hepatogenic photosensitization in lambs supplemented with different levels of extruded urea in Brachiaria spp. pastures in the Brazilian Cerrado: Case report

The aim was to report cases and risk factors for hepatogenous photosensitization in lambs kept on Brachiaria spp. pastures and supplemented with levels of extruded urea (EU). The herd consisted of 69 Texel crossbred lambs with known parentage (fathers and mothers adapted to the consumption of forage of the genus Brachiaria), randomly divided into 5 groups and distributed in individual paddocks for each group. The animals were supplemented with increasing levels of EU (Amireia® 200S): 0, 6, 12, 18, and 24 g of EU per 100 kg−1 of body weight (BW). The concentration of protodioscin was estimated in the mixed pastures of Brachiaria spp. (cv. Marandu and cv. Basilisk), structural components (leaf, stem, and dead material), samples of each cultivar, and in the months of December (2018), February, and April (2019). The animals were examined daily, and when behavioral changes were identified, they underwent clinical examinations and anamnesis. Weighing was performed every 14 days, followed by necropsy and serum biochemical analysis, including gamma-glutamyltransferase (GGT). The highest concentrations of protodioscin (p < 0.0001) were found in the pastures used by animals supplemented without extruded urea (7.07 ± 0.56), in the Basilisk cultivar (11.35 ± 0.06), in the leaf blade components (2.08 ± 0.05), and thatch (2.20 ± 0.00), and in the month of April (7.34 ± 0.29) (the month with the lowest rainfall), respectively. Fourteen (20.29%) cases of photosensitization were observed in lambs, of which six recovered, and eight died. Serum GGT levels ranged from 42.2 to 225 IU/L; however, in animals that died, values ranged from 209.4 to 225 IU/L. The use of levels 12 g and 18 g per 100 kg−1 of body weight of extruded urea may contribute to the lower occurrence of photosensitization, as the animals selected pastures with lower protodioscin content, presenting a smaller number of cases.

Doenças de pele diagnosticadas em bovinos na região sul do Rio Grande do Sul

ABSTRACT: A retrospective study of skin diseases diagnosed in cattle from 2000 to 2022 was performed at the “Laboratório Regional de Diagnóstico” of the “Faculdade de Veterinária” of the “Universidade Federal de Pelotas” (LRD-UFPel) to determine the main skin diseases that affect cattle in southern Brazil. Information regarding epidemiological data, lesions and diagnosis was collected. The diseases were grouped into infectious/inflammatory, toxic, nonneoplastic proliferative and neoplastic. The macroscopic aspects, distribution, histopathology, and evolution of the lesions were obtained in the protocols, and the original diagnosis was preserved. The main skin diseases diagnosed during this period occurred during outbreaks. They were infectious, with an emphasis on dermatophilosis, papillomatosis and dermatophytosis, followed by hepatogenous photosensitization, which was included in the group of toxic diseases. Among the neoplasms, squamous cell carcinoma stood out, occurring in isolated cases, reflecting an irrelevant cause of economic losses.

Intoxicação espontânea e experimental por Myrocarpus frondosus em bovinos

ABSTRACT: An outbreak of photosensitization in Holstein and Jersey cattle occurred after the passage of an extratropical cyclone in Southern Brazil. On that occasion, several trees fell, including some of the species Myrocarpus frondosus (Fabaceae family) popularly known as “gabreúva”, “cabriúna” or “gabriúna”. Five heifers consumed the leaves of this plant, and all of them became ill. The main clinical signs were decreased appetite, permanence in the water, decreased ruminal movements, dry stools, congested and icteric sclera and conjunctivae, dark urine and restlessness when exposed to the sun. One heifer showed circling, incoordination, restlessness and death six days after the onset of clinical signs. From the seventh day, three heifers showed improvement; one remained apathetic, with jaundiced mucous membranes, ulceration, and scaling on the tongue, increased respiratory rate, and fever, and died 18 days after ingestion of the plant. At necropsy, photosensitivity lesions were observed on the depigmented skin, snout, teats, and ear tip, characterized by discontinuity of the skin with the formation of crusts, inflammatory exudate associated with redness of the skin, in addition to ulceration in the mouth, snout and ventral portion of the tongue and jaundice and edema in the submandibular region. The liver was enlarged, with an orange color, full gallbladder, and wall edema. Through microscopy, liver lesions were characterized by moderate and diffuse necrosis of hepatocytes, vacuolar and centrilobular degeneration, bilirubin retention and proliferation of biliary epithelium. The literature shows no reports of M. frondosus toxicity in cattle. Experiments were carried out in cattle to clarify the possible clinical-pathological picture produced by this plant. A survey of the epidemiological data of the diagnosed spontaneous outbreak was carried out, and subsequently, three cattle received the plant’s green leaves, and a fourth received the dried leaves. After administering the plant, blood samples were collected daily for blood count, measurement of liver enzymes (gamma glutamyl transferase, alkaline phosphatase, alanine aminotransferase, aspartate transferase), bilirubin, measurement of vital parameters and liver biopsy from the onset of signs. In case of death, a necropsy was performed with collection of viscera samples for macro and microscopic evaluation. The experimental part was developed at the Laboratory of Animal Pathology, CAV-UDESC. The single dose of 33g/kg of green leaves caused severe clinical signs, while the administration of 22g/kg and 11g/kg caused mild to moderate signs of the disease. The supply of desiccated leaves in a single dose did not cause clinical manifestations. M. frondosus can be blamed as a cause of spontaneous hepatogenous photosensitization in cattle. Experimentally, the ingestion of green leaves of this plant, in doses greater than 11g/kg can lead to clinical changes, with subsequent recovery, or progress to death with severe liver damage.

Presumptive hepatogenous photosensitization in beef cattle winter grazing a cover crop containing Brassica spp. turnips.

Over a period of ~2 wk, 5 adult beef cows developed severe necrotizing skin lesions on the face and neck shortly after being moved to a field with a cover crop of Brassica spp. turnips. We describe here the clinical signs, hematology, and serum chemistry results, as well as gross and histopathologic findings, from this outbreak. We made a presumptive diagnosis of Brassica-associated liver disease (BALD) based on the similarities in the history and diagnostic findings observed with previously reported cases of BALD from elsewhere in the world. BALD has not been reported previously in cattle in North America, to our knowledge, despite the increasing usage of cover crops to improve soil conditions and provide forage for livestock. After the presumptive diagnosis of BALD was made, the cattle were removed from the turnip field and no additional cases were noted by the producer. BALD is well known in other parts of the world, and veterinarians and diagnosticians should be aware of this condition given that the usage of cover crops is likely to continue to increase.

Chronic pithomycotoxicosis associated with obstructive rhinopathy in sheep

Pithomycotoxicosis (facial eczema) is a seasonal hepatogenous photosensitization of sheep caused by the ingestion of sporidesmin contained in the spores of the fungus Pithomyces chartarum. We describe 4 cases of obstructive rhinopathy associated with chronic pithomycotoxicosis naturally occurring in the north of Spain. Sheep were 5 to 7 years old and Latxa breed. A detailed clinical study was conducted together with computerized tomography examination and completed by necropsy and histopathology. All sheep developed a permanent narrowing of the nasal lumen close to the nostrils causing inspiratory dyspnea and snoring. Computerized tomography demonstrated a significant increase of soft tissue in the rostral nasal cavity. Elevated gamma-glutamyl transferase, alanine aminotransferase, and lipase were noted on serum biochemistry. At necropsy, liver atrophy and fibrosis associated with chronic pithomycotoxicosis was identified in 3 of the sheep. All sheep had whitish elevations and rough surfaces on the alar folds and areas adjacent to the nasal surfaces. Histopathologic assessments, which included histochemical and immunohistochemical techniques, of the nasal lesions identified moderate to severe arteriosclerosis in 21.5% to 61.9% of the small arteries evaluated with surrounding fibrosis and edema. No changes associated with hypersensitivity reactions were found. These lesions were similar to the ones described in blood vessels of the liver in chronic pithomycotoxicosis and in our cases. The results of this study suggest a direct action of the sporidesmin on the rostral nasal cavity. Further studies are needed to analyze the impact of the sporidesmin on the sheep nasal mucosa.

First case of pithomycotoxicosis in sheep in the Netherlands

AbstractPithomycotoxicosis, commonly known as facial eczema, is a hepatogenous photosensitisation in grazing ruminants caused by intake of sporidesmin‐containing spores of the saprophytic fungus Pithomyces chartarum. Although this is a significant sheep disease in various countries in the world, it is rarely seen in Europe, and has been reported only once in the Netherlands, but in cattle. In October 2019, both sheep and lambs in a flock of 50 breeding sheep showed clinical signs of photosensitisation, including oedematous facial swelling, reddening of eyelids, ulcerative skin lesions, hyperpigmentation, and in some cases icteric sclerae. The combination of clinical signs, seriously elevated glutamate dehydrogenase, gamma‐glutamyl transferase and total bilirubin, necropsy findings, course of events, time of the year, absence of known toxic plants or mycotoxins, strongly suggest that sporidesmin was the most probable cause of this case of hepatogenous photosensitisation, which makes this the first reported case of pithomycotoxicosis in sheep in the Netherlands.

Genotypic identification of Panicum spp. in New South Wales, Australia using DNA barcoding

Australia has over 30 Panicum spp. (panic grass) including several non-native species that cause crop and pasture loss and hepatogenous photosensitisation in livestock. It is critical to correctly identify them at the species level to facilitate the development of appropriate management strategies for efficacious control of Panicum grasses in crops, fallows and pastures. Currently, identification of Panicum spp. relies on morphological examination of the reproductive structures, but this approach is only useful for flowering specimens and requires significant taxonomic expertise. To overcome this limitation, we used multi-locus DNA barcoding for the identification of ten selected Panicum spp. found in Australia. With the exception of P. buncei, other native Australian Panicum were genetically separated at the species level and distinguished from non-native species. One nuclear (ITS) and two chloroplast regions (matK and trnL intron-trnF) were identified with varying facility for DNA barcode separation of the Panicum species. Concatenation of sequences from ITS, matK and trnL intron-trnF regions provided clear separation of eight regionally collected species, with a maximum intraspecific distance of 0.22% and minimum interspecific distance of 0.33%. Two of three non-native Panicum species exhibited a smaller genome size compared to native species evaluated, and we speculate that this may be associated with biological advantages impacting invasion of non-native Panicum species in novel locations. We conclude that multi-locus DNA barcoding, in combination with traditional taxonomic identification, provides an accurate and cost-effective adjunctive tool for further distinguishing Panicum spp. at the species level.

Hepatogenous photosensitisation in cows grazing turnips (Brassica rapa) in South Africa.

Holstein cows on a farm in the Humansdorp district, Eastern Cape province, South Africa, developed reddened, painful teat skin 3 days after grazing a mixed forage crop dominated by bulb turnip (Brassica rapa, Barkant cultivar). The crop was grazed 45 days after planting and 10% of the herd developed symptoms. More characteristic non-pigmented skin lesions started manifesting 1–2 days after the appearance of the teat lesions. Affected cows had elevated serum activities of gamma-glutamyl transferase, glutamate dehydrogenase and aspartate aminotransferase. These blood chemistry findings confirmed a secondary (hepatogenous) photosensitivity. As a result of the severity of the teat and skin lesions, seven cows were slaughtered and tissue samples from five of them were collected for histopathological examination. Liver lesions in cows that were culled 3 or more weeks after the onset of the outbreak showed oedematous concentric fibrosis around medium-sized bile ducts and inflammatory infiltrates in portal tracts. Characteristic lesions associated with other known hepatobiliary toxicities were not found. No new cases were reported 5 days after the cattle were removed from the turnips. The sudden introduction of the cows, without any period of transitioning or adaptation to grazing turnips, as well as the short latent period, clinical signs of photosensitisation, blood chemistry and histopathology, confirmed a diagnosis of Brassica-associated liver disease, a condition seen in New Zealand but not previously described in South Africa. Brassica forage crops are potentially toxic under certain conditions and farmers must be aware of these risks.

Hepatogenous photosensitization in ruminants and horses caused by the ingestion of Chamaecrista serpens in Brazil

This study aimed to describe the first reports of outbreaks of hepatogenous photosensitization in cattle, sheep, and horses caused by spontaneous ingestion of Chamaecrista serpens, as well as to reproduce poisoning in sheep experimentally. Eleven photodermatitis outbreaks of unknown cause occurred in cattle, sheep and horses on nine farms in the semiarid region of Bahia, northeastern Brazil, between July 2017 and July 2020. Cutaneous lesions of photosensitization initiated until one week after the animals were introduced in paddocks invaded by the plant at the beginning of the rainy season. The photosensitive skin lesions were progressive and consisted of hyperemia, edema, ulcerative-crusted lesions with necrosis, especially in non-pigmented skin areas. The lesions in young animals were more severe. The animals avoided the sun and exhibited hyporexia, weight loss, restlessness, irritability, and severe itching. An experimental study was made using seven sheep, and resulted in photodermatitis, similar to that observed in the natural poisoning, seven days after the beginning of plant ingestion. Two sheep were reserved for the control group. Serum biochemistry changes indicated liver injury caused by the plant. Skin biopsies and liver biopsy guided by ultrasound were performed. The one sheep that had more pronounced skin lesions was euthanized and necropsied. At the necropsy, the liver was enlarged, diffusely pale, and firm, with an evident lobular pattern and an empty gallbladder. Histopathology revealed similar skin and liver lesions in samples from biopsies and the necropsy. There was a marked disorganization of the cords of hepatocytes associated with degenerative necrotic changes on the liver. The cutaneous injuries included orthokeratotic hyperkeratosis, hypergranulosis, acanthosis, and extensive areas of epidermic necrosis and ulceration. Three sheep were protected from sunlight and the lesions regressed within 45 days after the plant's consumption ceased. In conclusion, C. serpens causes hepatogenous photosensitization in ruminants and horses, and should be included in the list of differential diagnoses in cases of photosensitive dermatitis.

Hepatogenous Photosensitization in Steer by Brachiaria decumbens

Background: Although the etiology of hepatogenous photosensitization has not yet been fully elucidated, it is known that hepatotoxic substances (saponins) present in grasses of the genus Brachiaria spp. are responsible for intoxication of several species, causing great economic losses in the whole world. Since this grass is the source of food for the herd in Brazil, and other countries of the world, the aim of this paper is to describe the epidemiological, clinical, laboratory and anatomopathological aspects of a steer with this disease.Case: A 3-year-old Nellore steer was referred to veterinary care at a property in Bahia, with a 3-week history of swelling, loss of cutaneous tissue in the ear and scrotum region, and dry faeces. The animal was raised in pasture with Brachiaria decumbens along with five animals of different age and sex; however, it was the only one to present symptoms. Although the animal had been treated at the farm, there was no clinical improvement. On clinical examination, the steer was apathetic with jaundiced mucous membranes, nasal and ocular discharge, epiphora, and ulcers on the labial and gum commissure. The steer had leukocytosis with neutrophilia, anemia, and hyperfibrinogemia. The body condition score (BCS) was 3 (BCS ranges from 1 to 9), and the skin lesions observed were bedsores, necrosis and scabs in several regions. The increase in liver enzymes (GGT, AST) indicated hepatic impairment, suggesting a case of hepatogenous photosensitization. The therapeutic protocol instituted was enteral hydration, electrolyte replacement, topical application of ointment in the injured areas. In addition, it was recommended to maintain the animal in the shade, supply of good quality grass, and a new clinical evaluation in seven days. On new examination, it was observed that there was no satisfactory clinical improvement of the animal, and persistence of laboratory changes. Despite the poor prognosis, treatment was continued for another month with the same recommendations. However, in view of the severe clinical condition and unfavorable prognosis, the animal was submitted euthanasia. Necropsy revealed extensive areas of bedsores, erythema, severe jaundice in the mucous membranes, eyeballs and opaque corneas. The liver had an enlarged volume with bulging edges and a greenish color. The kidneys had a pale brownish color, with an irregular and mottled subcapsular surface, with blackened and depressed spots. Histologically, the cytoplasm of the hepatocytes was finely vacuolated, sometimes refringent and with an abundant presence of bile pigment. It was also observed in the middle of the liver parenchyma, multiple foci of accumulation of macrophages filled with vacuoles of different sizes containing saponins and crystals of saponins inside bile ducts. Furthermore, it was possible to observe hypertrophy and hyperplasia of Kupffer cells, disarrangement of hepatocytes with individual necrosis of hepatocytes.Discussion: The diagnosis of hepatogenous photosensitization was based on history, clinical, laboratory and anatomopathological findings. Serum biochemistry was important to measure hepatic impairment and possible secondary lesions, which were confirmed by the necropsy. Although hepatogenous photosensitization is less common in adult cattle, it must be considered in the differential diagnosis of skin lesions, reduced appetite, and jaundice. Since it was a sporadic case, individual predisposition is probably a preponderant factor. Keywords: cattle, photodermatitis, intoxication, liver injury, skin lesions.

Protodioscin levels in Brachiaria spp. in a sheep production system and a brief review of the literature of Brachiaria spp. poisoning in ruminants

ABSTRACT: Plants of the genus Brachiaria, used in several countries as forage, are poisonous to some livestock species. Their toxic principle is protodioscin, and the main form of clinical presentation of the toxicosis is hepatogenous photosensitization. Here we compare protodioscin levels in B. decumbens and B. brizantha and review the literature on the concentrations and methodologies of collection and analysis of the toxic principle in Brachiaria spp. and the risk of contamination of pastures by more toxic species that may facilitate poisoning by plants of this genus in sheep. The experiment was conducted in pastures originally formed by B. brizantha, with many B. decumbens invasion points. The occurrence of cases of poisoning by Brachiaria spp. was the criterion for confirming pasture toxicity. The forage samples were collected at ten random points every 28 days through manual grazing simulation. The samples were analyzed for protodioscin by high-performance liquid chromatography (HPLC) with light scattering by evaporation (ELSD) after being dried and crushed. In the flock of 69 sheep, five poisoning cases occurred, three sheep died, and two recovered. The protodioscin levels found in the evaluated pastures ranged from 0.70 to 0.45%; higher levels appeared in B. decumbens (7.09%) compared to 1.04% in B. brizantha. We suggest that Brachiaria spp. should be avoided in pastures where sheep are grazing.

Hepatogenous photosensitization by Brachiaria spp. in sheep: first report in Mexico

Hepatogenous photosensitization by Brachiaria spp. in sheep: first report in Mexico

The aetiology, prevalence and morbidity of outbreaks of photosensitisation in livestock: A review.

BackgroundPhotosensitisation is a clinical condition occurring in both humans and animals that causes significant injury to affected individuals. In livestock, outbreaks of photosensitisation caused by ingestion of toxic plants are relatively common and can be associated with significant economic loss.ObjectivesThe agents that are most commonly implicated in outbreaks of photosensitisation have not been formally investigated on a global scale. To address this question, a systematic review of the literature was undertaken to determine the most common causative agents implicated in outbreaks of photosensitisation in livestock in Australia and globally, as well as the prevalence and morbidity of such outbreaks.MethodsA systematic database search was conducted to identify peer-reviewed case reports of photosensitisation in livestock published worldwide between 1900 and April 2018. Only case reports with a full abstract in English were included. Non peer-reviewed reports from Australia were also investigated. Case reports were then sorted by plant and animal species, type of photosensitisation by diagnosis, location, morbidity and mortality rate and tabulated for further analysis.ResultsOne hundred and sixty-six reports qualified for inclusion in this study. Outbreaks were reported in 20 countries. Australia (20), Brazil (20) and the United States (11) showed the highest number of peer-reviewed photosensitisation case reports from this analysis. Hepatogenous (Type III) photosensitisation was the most frequently reported diagnosis (68.5%) and resulted in higher morbidity. Panicum spp., Brachiaria spp. and Tribulus terrestris were identified as the most common causes of hepatogenous photosensitisation globally.ConclusionsHepatogenous photosensitisation in livestock represents a significant risk to livestock production, particularly in Australia, Brazil, and the United States. Management of toxic pastures and common pasture weeds may reduce the economic impact of photosensitisation both at a national and global level.

Labia and Lingua Histopathology of Bali Cow (Bos sondaicus) on Hepatogenous Photosensitization Symptoms in Pakutatan Village, Jembrana, Bali

Hepatogenous photosensitization is one of the ruminant diseases with symptoms of dermatitis or eczema of the skin accompanied by liver damage. The disease is caused by the compounds of toxic lantadene A and lantadene B which are secondary metabolites of Lantana camara plant. This research was carried out on January 2017. The material used in this study was preserved organs of the labia and lingua of dead three year old cow (Bos sondaicus). Samples were taken from Pakutatan Village, Jembrana, Bali. Identification of organ samples, histological preparation and histopathological examination were conducted at the Disease Investigation Center (DIC) 6, Denpasar, Bali. The preparation of labia and lingua samples used the paraffin method with Hematoxylin and Eosin staining. The tissue structural damages found were necrosis, inflammatory cell infiltration, congestion and tissue bleeding. The data obtained were analyzed statistically by One Way Anova test with a confidence level of 95%. Based on the results, dead Bali cow which consumed a large numbers of Lantana camara plants showed that the highest number of cell damage was at the picnotic stage of cell necrosis (cell death) in the labia organ significantly (P&lt;0.005), while the highest bacterial invasion was found in the labia organ with an average percentage of 12.40%.

Poisoning of cattle by Senecio spp. in Brazil: a review

ABSTRACT: 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. 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. Senecio brasiliensis is the main species associated with natural intoxication of livestock in Brazil, and the number of cases associated with the ingestion of S. madagascariensis is increasing. The toxic principle of Senecio spp. comprises the hepatotoxic alkaloids of the pyrrolizidine group (pyrrolizidine alkaloids, PAs). The resulting liver lesions are chronic and irreversible and result from the inhibition of hepatocellular mitosis. Deaths of adult cattle may occur both sporadically and in larger outbreaks over an extended period of time. In cattle raising, Senecio spp. are consumed mainly during the winter, when there is a dearth of forage; at this time the poisonous Senecio species are budding and contain high concentrations of PAs. Spontaneous Senecio spp. intoxication in cattle is a chronic condition that frequently involves acute clinical manifestations. Affected cattle may present ascites, emaciation, intermittent dark diarrhea, tenesmus, rectal prolapse, and neurological signs resulting from hepatic encephalopathy. Hepatogenous photosensitization may be observed but is uncommon. Necropsy findings include dependent subcutaneous edema, ascites, and edema of the mesentery, abomasal folds, and gallbladder. The liver is firm, normal or reduced in size with a white, thick capsule. Microscopically, the hallmarks of Senecio-associated disease are varying degrees of hepatocellular megalocytosis, bile duct hyperplasia and fibrosis. Sheep are significantly more resistant to Senecio intoxication than are cattle and avidly ingest Senecio plants; therefore, the use of sheep for grazing infested pasture is recommended for preventing the associated disease in cattle.

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

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 &amp; 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.

STEROIDAL SAPONIN TOXICITY IN EASTERN GREY KANGAROOS ( MACROPUS GIGANTEUS): A NOVEL CLINICOPATHOLOGIC PRESENTATION OF HEPATOGENOUS PHOTOSENSITIZATION.

We describe the clinicopathologic features of a mortality event characterized by blindness and dermatitis affecting eastern grey kangaroos ( Macropus giganteus), secondary to hepatogenous photosensitization. Affected animals exhibited photophobic behavior, blindness, ataxia, recumbency, lethargy, ear shaking, and behavior consistent with distress or depression. The photophobia manifested as abnormal shade-seeking during the day, including finding refuge under or in structures used frequently by people. Severely affected kangaroos were jaundiced and had markedly elevated serum bilirubin and gamma glutamyl-transpeptidase concentrations. Blindness in affected animals was attributed to moderate to severe corneal opacity due to corneal edema and inflammation. Skin lesions were typically subtle on gross examination even in cases which had severe necrotizing dermatitis histologically. Histologic lesions in the liver of affected animals included the presence of acicular clefts typical of steroidal saponins. The outbreak was associated with pasture dominated by the invasive grass, Panicum gilvum, which is a recognized source of saponin-induced photosensitization in livestock.

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

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.

Experimental poisoning by Enterolobium contortisiliquum in sheep

ABSTRACT: Ingestion of Enterolobium contortisiliquum pods causes digestive disturbances, secondary hepatogenous photosensitization and abortions in ruminants. Pods were administered to sheep via a ruminal cannula to characterize acute poisoning. In Experiment 1, a single dose of 12g/kg of body weight (BW) was administered to three sheep in one experiment. One sheep died, and the other two recovered after presenting clinical signs. In Experiment 2, 10g/kg BW were administered daily to 15 sheep until the onset of clinical signs or for three consecutive days. Fourteen sheep showed mild to severe signs after the ingestion of 1-3 doses. Two sheep died, and the others recovered. Clinical signs in both experiments were diarrhea, anorexia, rumen atony, apathy, dehydration and tachypnea. The main macroscopic findings were an orange, frothy ruminal content witch contained pods fragments. The intestinal content was liquid. Detachment of the mucosa from the submucosa and ballooning degeneration of mucosal cells were observed histologically in the forestomachs. Evaluation of ruminal contents revealed acute lactic ruminal acidosis (ALRA). Bromatological analysis of E. contortisiliquum pods revealed 537.8g/kg DM (dry matter) of non-fibrous carbohydrates, which is sufficient to cause ALRA. Only one sheep in Experiment 2 had liver failure, characterized by jaundice, elevated serum activity of liver enzymes and histological lesions in liver biopsies. It is concluded that the administration of E. contortisiliquum pods in forage-fed sheep at doses of 10g/kg BW or higher may cause ALRA. The induction of liver failure in one sheep suggests that liver damage may occur in those sheep that do not develop acidosis.

Hepatotoxicity in sheep and goats caused by experimental feeding with foxtail millet (Setaria italica)

Background: Some species of grass cause poisoning and hepatogenous photosensitization in animals. OBJECTIVES: Feeding trials were conducted in sheep and goats to evaluate the hepatotoxic effects of Setaria italica (S. italica). METHODS: Twelve indigenous male sheep and goats were used in this study. The animals were kept outdoors against prevailing climatic conditions. They were fed with S. italica freely for 50 days. Some biochemical factors associated with liver function, such as total bilirubin (TBIL), direct bilirubin (BC), aspartate amino transferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), gamma glutamyltransferase (GGT) activities, blood urea nitrogen (BUN), total protein (TP), and albumin (ALB), were measured on day 0, 7, 14, 21, 28, 35, 42, and 49 of the experiment. On the 50th day, the animals were sacrificed and necropsied, then the gall bladder and livers were removed for pathological study. Blood samples on day 0 (prior to feeding with S. italica) were set as the control group. RESULTS: Three sheep and 3 goats showed signs of intoxication, including facial edema, mucus hyperemia, runny nose, lacrimation, and icterus. Post-mortem examination revealed varying degrees of generalized icterus, degeneration, necrosis and cell swelling of hepatocytes, formation of acidophilic bodies, and mild hyperplasia in biliary ducts. CONCLUSIONS: Clinical signs, laboratory findings, and necropsy findings, support the potential of S. italica in the induction of hepatotoxicity and secondary photosensitivity in sheep and goats.