Hematuria and urinary bladder lesions compatible with bracken fern (Pteridium aquilinum) intoxication in captive fallow deer (Dama dama)

Health and Environmental Hazards of the Toxic Pteridium aquilinum (L.) Kuhn (Bracken Fern)

Bracken fern (Pteridium aquilinum (L.) Kuhn) is ubiquitous and acts as a cosmopolitan weed in pastures and similar environments. Despite its historical uses, it presents risks due to toxicity. This study, conducted in the second half of 2023, aimed to assess the environmental and health hazards of P. aquilinum, primarily focusing on its carcinogenic compound, ptaquiloside. The literature was comprehensively reviewed using diverse databases, including PubMed, Web of Science, Scopus, and Google Scholar. Information was synthesized from original research articles, meta-analyses, systematic reviews, and relevant animal studies. Animals grazing on bracken fern face annual production losses due to toxin exposure. The substantial impact on biodiversity, animal health, and human well-being arises from the presence of ptaquiloside and related compounds in milk, meat, and water, along with the increasing global prevalence of P. aquilinum and its swift colonization in acidic soil and fire-damaged areas. The objectives were to identify major bioactive compounds and explore their effects at molecular, cellular, pathological, and population levels. Various cooking techniques were considered to mitigate toxin exposure, although complete elimination remains unattainable. Therefore, the findings emphasize the need for cautious consumption. In conclusion, continued research is necessary to better understand and manage its environmental and health implications.

A case of eagle fern (Pteridium aquilinum) poisoning on a pig farm

Background

Free-range pig farming represents a minor proportion of pig production in France but is attracting an increasing number of farmers because of societal expectations and the opportunity to use pasture-grazed forage. However, this type of farming faces several challenges, including biosecurity, parasitic management, and contact with wild fauna and pathogenic flora.

Case presentation

Two Gascon pigs raised on an outdoor fattening farm in the Hautes-Pyrenees department of France were submitted after sudden death for necropsy at the National Veterinary School of Toulouse. The pigs were of two different breeds but from the same group of 85 animals that had grazed on a 4-ha plot of land being used for grazing for the first time. Based on an in-depth interview with the farmer, the epidemiological information available, and the necropsy and histology examinations, a hypothesis of great eagle fern intoxication was proposed. Although the sample of animals available for diagnosis was small, the success of the administered therapy confirmed our diagnosis. It was recommended that in the short term, the animals be prevented access to the eagle fern by changing their pasture or removing the plants. Vitamin B1 and vitamin B6 were administered via feed as Ultra B® at 1 mL per 10 kg body weight per day for 2 days (providing 9 mg thiamine (vitamin B1) and 0.66 mg pyridoxine (vitamin B6) per kg body weight per day). Marked remission was observed, with 6 of 10 intoxicated animals with symptoms surviving (yielding a therapeutic success rate over 50%), but the therapy did not compensate for the loss of initial body condition. In total, of the 85 animals in the group after intoxication, 6 died, and 6 recovered.

Conclusions

The significance of this report lies in the scarcity of eagle fern intoxication cases reported in the literature, though such intoxication may become a significant problem as the development of outdoor rearing continues. Thus, eagle fern intoxication should be included in the differential diagnosis of nervous system symptoms in swine. The case also emphasizes the importance of anamnesis and discussion with the farmer as an essential step to guide diagnosis.

Intestinal Myxoid Leiomyosarcoma in a Sambar Deer (Rusa unicolor)

A 9-year-old male sambar deer (Rusa unicolor) that died during sedation had a large and firm polypoid mass, which expanded the small intestinal wall and partially obstructed the duodenal lumen. Histopathology revealed a pleomorphic sarcoma composed of stellate to spindloid cells loosely arranged in an abundant myxoid matrix. The cytoplasm of the neoplastic cells was strongly immunopositive for vimentin and smooth muscle actin, but negative for c-KIT, desmin and myoglobin. The findings are consistent with intestinal myxoid leiomyosarcoma, which is rare in cervids and has not been described in the sambar deer, which is an endangered species.

Ptaquiloside, the major carcinogen of bracken fern, in the pooled raw milk of healthy sheep and goats: an underestimated, global concern of food safety

Bracken fern (Pteridium aquilinum) is a worldwide plant containing toxic substances, which represent an important chemical hazard for animals, including humans. Ptaquiloside, 1, a norsesquiterpenoid glucoside, is the major carcinogen of bracken detected in the food chain, particularly in the milk from farm animals. To date, ptaquiloside has been shown in the milk of cows feeding on a diet containing bracken fern. This is the first study that shows the systematic detection of ptaquiloside, 1, and reports its direct quantitation in pooled raw milk of healthy sheep and goats grazing on bracken. Ptaquiloside, 1, was detected by a sensitive method based on the chemical conversion of ptaquiloside, 1, into bromopterosine, 4, following gas chromatography-mass spectrometry (GC-MS) analysis. The presence of ptaquiloside, 1, possibly carcinogenic to humans, in the milk of healthy animals is an unknown potential health risk, thus representing a harmful and potential global concern of food safety.