Bovine enzootic haematuria from consumption of Pteris deflexa and Pteris plumula in northwestern Argentina

Plants causing poisoning outbreaks of livestock in South America: A review

This paper reviews toxic plants for livestock in South America. We included 219 plants in this review, considering only the plants that caused at least one demonstrated outbreak of poisoning. Plants reported as toxic in other regions and present in South America, but with no confirmed outbreaks of poisoning in this region, are not included. We report the main aspects of the epidemiology, clinical signs, pathology and economical importance of the poisonings. Initially, the toxic plants are described based on their toxic compounds, but because the toxic compound is unknown in 92 (42%) of the plants we also classify them according to the affected system. This review highlights the great diversity of toxic plants capable of affecting livestock in South America, and for this reason studies in this regard should be intensified.

Molecular Markers in Urinary Bladder Cancer: Applications for Diagnosis, Prognosis and Therapy

Cancer of the urinary bladder is a neoplasm with considerable importance in veterinary medicine, given its high incidence in several domestic animal species and its life-threatening character. Bladder cancer in companion animals shows a complex and still poorly understood biopathology, and this lack of knowledge has limited therapeutic progress over the years. Even so, important advances concerning the identification of tumour markers with clinical applications at the diagnosis, prognosis and therapeutic levels have recently been made, for example, the identification of pathological BRAF mutations. Those advances are now facilitating the introduction of targeted therapies. The present review will address such advances, focusing on small animal oncology and providing the reader with an update on this field. When appropriate, comparisons will be drawn with bladder cancer in human patients, as well as with experimental models of the disease.

Hemorrhagic diathesis in cattle due to consumption of Adiantopsis chlorophylla (Swartz) Fée (Pteridaceae)

An outbreak of acute febrile syndrome associated with coagulopathy and severe pancytopenia occurred in cattle grazing in paddocks with high infestation by Adiantopsis chlorophylla. The administration of the plant to a calf reproduced the same signs and lesions seen in spontaneous cases. Similar syndromes are caused by ptaquiloside from bracken fern. Traces of the ptaquiloside-like molecule caudatoside were detected together with 0.03-0.24 mg/g of it's degradation product pterosin A, in dry fronds of the plant. In conclusion, A. chlorophylla is a cause of hemorrhagic diathesis in cattle.

Ptaquiloside and Pterosin B Levels in Mature Green Fronds and Sprouts of Pteridium arachnoideum

Pteridium arachnoideum, a fern of the Pteridium aquilinum species complex found in South America, is responsible for several different syndromes of poisoning. Cases of bovine enzootic hematuria and upper alimentary squamous cell carcinoma are both frequent occurrences in Brazil, whereas only bovine enzootic hematuria is noted with any frequency around the world. The reason for the high frequency of upper alimentary squamous cell carcinoma in Brazil is not currently known. One possible explanation may be the higher levels of ptaquiloside and pterosin B in Brazilian Pteridium than those present in the plant in other countries. However, these levels have not yet been determined in P. arachnoideum. Thus, the present study aimed to measure and compare ptaquiloside and pterosin B levels in mature green fronds and sprouts of P. arachnoideum collected from different locations in Brazil. Samples of P. arachnoideum were collected from the states of Minas Gerais and Rio Grande do Sul. A total of 28 mature leaf samples and 23 sprout samples were used. The mean concentrations of ptaquiloside and pterosin B present in the mature green fronds of P. arachnoideum ranged from 2.49 to 2.75 mg/g and 0.68 to 0.88 mg/g, respectively; in P. arachnoideum sprouts, mean concentrations of ptaquiloside and pterosin B ranged from 12.47 to 18.81 mg/g, and 4.03 to 10.42 mg/g for ptaquiloside and pterosin B, respectively. Thus, ptaquiloside and pterosin B levels in P. arachnoideum samples collected in Brazil were higher in sprouts than in mature green fronds, as observed in other countries. However, there was no variation in ptaquiloside levels among plants collected from different cities in Brazil. The high frequency of upper alimentary squamous cell carcinoma in Brazilian cattle may not be attributed to greater levels of ptaquiloside and pterosin B in P. arachnoideum than in other Pteridium species in other countries.

Weedy ferns (Polypodiopsida) in Argentina: diversity, distribution and impact on human activities and ecosystems

Currently, in Argentina 368 species of true ferns (i.e. Polypodiopsida class) are distributed throughout the country, however, only four of them have been mentioned until now as weeds and ruderal species. The goal of this work was to generate an update of weedy ferns from Argentina, including morphology, distribution, and type of weed according to their impact on natural habitats and/or human activities. All Argentinian fern species were analyzed based on references, herbarium specimens, and field trips. As a result of our study 25 species were recorded from Argentina and classified as segetal, ecological, or aquatic weeds, and ruderal and/or toxic species. Current taxonomic identity, diagnostic characters, origins, habitats, geographical distribution, common names, and impact and potential risks were indicated by species. In addition, we provide a dichotomous key to species, presence of these species in southern South American countries, as well as and photographs in natural habitat. This work represents the first review on native and exotic ferns from Argentina that cause an impact on human activities or disturbe native habitats. The results provide information for the development of weed management tools and priority areas to implement them.