Spontaneous and experimental poisoning by Froelichia humboldtiana in cattle / Intoxicação espontânea e experimental por Froelichia humboldtiana em bovinos

The aim of this work was to describe the epidemiological, clinical and pathological aspects of two outbreaks of spontaneous poisoning caused by Froelichia humboldtiana in cattle in Pernambuco, northeastern Brazil and reproduce experimentally this poisoning in cattle. Spontaneous poisonings of primary photosensitization occurred in two farms at the municipalities of Cachoeirinha and São Caetano and affected twenty-two adult bovines and two suckling calves after the rainy season. All bovines have recovered 21 days after they were removed from the pasture. To reproduce experimental poisoning, three cows and a calf were maintained in a pasture with 1ha composed by F. humboldtiana during 14 days. Clinical signs and skin lesions were similar in both spontaneous and experimental poisoning and consisted of cutaneous itching and hyperemia of non-pigmented areas of skin that evolved into edema, exudative dermatitis and extensive areas of skin necrosis. Serum levels of aspartate aminotransferase (AST), gamma glutamyltransferase (GGT), total, direct and indirect bilirubin were normal in all cattle examined. Histologically, lesions consisted of epidermal necrosis, hyperkeratosis with large amounts of degenerate neutrophils and acanthosis. In the dermis, edema and inflammatory infiltrate composed of eosinophils, lymphocytes and plasma cells mainly around the blood vessels were observed. In the experimental group, clinical signs of photosensitization were observed after the third day of F. humboldtiana consumption. The suckling calf displayed mild clinical signs of photodermatitis on the 8th day of the experiment. It was estimated that the average consumption of F. humboldtiana necessary to initiate clinical signs in each adult bovine was 78kg.(AU)

Os objetivos deste trabalho foram descrever os aspectos epidemiológicos, clínicos e patológicos de dois surtos de intoxicação por Froelichia humboldtiana em bovinos em Pernambuco e reproduzir experimentalmente essa intoxicação em bovinos. Intoxicações espontâneas foram observadas após o início do período chuvoso nos municípios de Cachoerinha e São Caetano. Vinte e dois bovinos apresentaram sinais clínicos e lesões cutâneas compatíveis com fotossensibilização primária, dentre os quais, dois bezerros lactentes. Todos os bovinos se recuperaram totalmente cerca de 21 dias após serem retirados da pastagem. Para reproduzir experimentalmente a intoxicação, três vacas, uma delas com bezerro ao pé, foram mantidas em um piquete de 1ha composto por F. humboldtiana por 14 dias consecutivos. O quadro clínico e as lesões tegumentares, tanto nos bovinos intoxicados nos surtos espontâneos, quanto nos bovinos do experimento consistiram em prurido e hiperemia em áreas despigmentadas de pele, que evoluíam para edema, dermatite exsudativa e necrose de áreas extensas de pele. Em todos os bovinos examinados, os níveis séricos de aspartato aminotransferase (AST), gamaglutamiltransferase (GGT), bilirrubina total, direta e indireta estavam normais. Histologicamente, as lesões consistiram em necrose da epiderme, hiperqueratose com grande quantidade de neutrófilos degenerados e acantose. Na derme havia edema e infiltrado inflamatório composto por eosinófilos, linfócitos e plasmócitos principalmente ao redor dos vasos sanguíneos. Nos bovinos do experimento, sinais clínicos de fotossensibilização foram observados após o terceiro dia de consumo de F. humboldtiana. O bezerro lactente apresentou sinais clínicos leves de fotodermatite no 8º dia do experimento. Estimou-se que o consumo médio de matéria seca de F. humboldtiana necessário para iniciar os sinais clínicos em cada bovino adulto foi de 78kg.(AU)

Wild parsnip (Pastinaca sativa)-induced photosensitization.

Wild parsnip (Pastinaca sativa) has been associated with livestock and human photosensitization. An investigation of a natural occurrence of photosensitization of grazing horses identified wild parsnip as a possible cause. HPLC-MS and MS/MS analysis of this plant identified five furanocoumarins i.e., xanthotoxin, bergapten, isopimpinellin, imperatorin and a putative methoxyimperatorin. Goats fed this wild parsnip were largely unaffected. Xanthotoxin was not detected in the serum of parsnip-fed goats or in the serum of goats dosed orally or intravenous with purified xanthotoxin. Cutaneous application produced severe photodermatitis in goats and a horse consistent with topical exposure as the likely route to produce wild parsnip-induced photosensitivity. Wild parsnip-induced superficial necrotizing dermatitis was consistent with photodermatitis with no evidence of other allergic or inflammatory components.

Secondary plant products causing photosensitization in grazing herbivores: their structure, activity and regulation.

Photosensitivity in animals is defined as a severe dermatitis that results from a heightened reactivity of skin cells and associated dermal tissues upon their exposure to sunlight, following ingestion or contact with UV reactive secondary plant products. Photosensitivity occurs in animal cells as a reaction that is mediated by a light absorbing molecule, specifically in this case a plant-produced metabolite that is heterocyclic or polyphenolic. In sensitive animals, this reaction is most severe in non-pigmented skin which has the least protection from UV or visible light exposure. Photosensitization in a biological system such as the epidermis is an oxidative or other chemical change in a molecule in response to light-induced excitation of endogenous or exogenously-delivered molecules within the tissue. Photo-oxidation can also occur in the plant itself, resulting in the generation of reactive oxygen species, free radical damage and eventual DNA degradation. Similar cellular changes occur in affected herbivores and are associated with an accumulation of photodynamic molecules in the affected dermal tissues or circulatory system of the herbivore. Recent advances in our ability to identify and detect secondary products at trace levels in the plant and surrounding environment, or in organisms that ingest plants, have provided additional evidence for the role of secondary metabolites in photosensitization of grazing herbivores. This review outlines the role of unique secondary products produced by higher plants in the animal photosensitization process, describes their chemistry and localization in the plant as well as impacts of the environment upon their production, discusses their direct and indirect effects on associated animal systems and presents several examples of well-characterized plant photosensitization in animal systems.

Heracleum Sosnowskyi Manden.

Heracleum Sosnowskyi was discovered in 1772 and described as a separate species in 1944 by I. P. Mandenova. Its name is derived from the surname of a botanist studying Caucasian flora, Prof. D.I. Sosnowski. In the area of the Caucasus foothills, the plant reaches approximately 1-1,5 m in height, whereas in Poland its size is significantly larger, up to 3-3.5 m. Heracleum blooms from mid-June to the end of July. The flowers are arranged in umbels and last for 2-3 weeks. In Central Europe, the species colonizes mostly neglected green areas, ruins and riversides. Heracleum poses a serious threat to the human population due to its photoallergic properties, resulting from the presence of intensely toxic furanocoumarin in its sap. Furanocoumarins are found in small hairs that cover the leaves and stem, and are the components of the essential oil. They may penetrate the skin through the epithelial layer, posing a direct threat to human health. Contact with the plant, followed by sun exposure, may lead to the development of large blisters and symptoms of burns. Heracleum, in the event of consumption, is also harmful to farm animals, causing, among others, internal bleeding and diarrhea. Although the toxic properties of Heracleum have been known for many years, every summer people who had contact with the plant present at physicians of different medical specialties.

Necrotic dermatitis in waterfowl associated with consumption of perennial rye grass (Lolium perenne).

Mute swans (Cygnus olor), whooper swans (Cygnus cygnus), and mixed-breed domestic geese (Anser anser domesticus) were presented for necrotic lesions on the feet, eyelids, and beak. Individuals from the same collection of birds had developed identical lesions during March-September of each of the previous 3 years. Vesicular and necrotic dermatitis involved only nonfeathered and nonpigmented areas of the integument. No abnormal clinical signs were seen on either carnivorous species or birds with pigmented skin from the same collection. The enclosure that housed the birds had been planted with perennial rye grass (Lolium perenne) 3 years previously. Based on the pathologic features and anatomic location of the lesions, the seasonal occurrence, the vegetation history of the enclosure, and the feeding behavior of the affected species, vesicular dermatitis resulting from photosensitization was the presumptive diagnosis. All affected birds recovered completely after the birds were removed from the enclosure, and no further clinical signs have been reported.

Dermatite solar felina associada a carcinoma epidermóide / Felinesolar dermatites associated to squamous cell carcinoma

A pele é um dos maiores sistemas do organismo animal, desempenhando importantes papéis e apresenta inúmeras alteraçöes que, frequentemente, levam os proprietários de animais domésticos a procurar os serviços veterinários. A dermatite solar felina é uma doença de natureza ambiental, que acomete gatos brancos ou aqueles que possuem áreas despigmentadas, principalmente nas orelhas e nariz. Esta doença, causada pela exposiçäo da pele despigmentada à radiaçäo ultravioleta, pode evoluir para carcinoma epidermóide nos casos de exposiçäo por período prolongado. A lesäo inicia-se com severo eritema da orelha, progredindo para descamaçäo cutânea e formaçäo de crostas marginais. O controle objetiva evitar o contato da pele despigmentada com a luz solar, principalmente nas horas mais quentes do dia. Para se atingir este objetivo, deve-se evitar que os animais entrem em contato com o sol, mantendo-os presos em horários estratégicos, utilizando filtros solares à base de creme ou ainda confeccionando tatuagens nas áreas despigmentadas. Após a instalaçäo do carcinoma epidermóide, diferentes métodos terapêuticos säo recomendados para o tratamento, dentre eles a cirurgia, com remoçäo total dos tecidos atingidos pela neoplasia, a radioterapia, a fotoquimioterapia, a hipertemia e a terapia com glicocorticóides.