Todayโs path rounds are on ๐๐ซ๐๐๐ค๐๐ง ๐๐๐ซ๐ง ๐ญ๐จ๐ฑ๐ข๐๐ข๐ญ๐ฒ!
๐๐ก๐๐ญ ๐ข๐ฌ ๐ข๐ญ?
๐๐ซ๐๐๐ค๐๐ง ๐๐๐ซ๐ง are plants of the Pteridium species, which are common in various places around the world. Bracken fern has several ๐๐๐ซ๐๐ข๐ง๐จ๐ ๐๐ง๐ข๐ (cancer-causing) toxins, which can cause issues for animals eating large amounts of the plant.
๐๐ก๐จ ๐ ๐๐ญ๐ฌ ๐ข๐ญ?
This disease is most commonly seen in cattle!
๐๐ก๐๐ญ ๐๐๐ฎ๐ฌ๐๐ฌ ๐ข๐ญ?
Bracken fern contains multiple carcinogenic toxins, the most significant of which is ๐ฉ๐ญ๐๐ช๐ฎ๐ข๐ฅ๐จ๐ฌ๐ข๐๐. This toxin stimulates growth of various types of ๐ง๐๐จ๐ฉ๐ฅ๐๐ฌ๐ฆ๐ฌ (tumours), particularly in the bladder and in gastrointestinal tract. These tumours include ๐ฉ๐๐ฉ๐ข๐ฅ๐ฅ๐จ๐ฆ๐๐ฌ (benign tumours of the lining cells), ๐๐ข๐๐ซ๐จ๐ฆ๐๐ฌ (benign tumours of the structural cells) and ๐ก๐๐ฆ๐๐ง๐ ๐ข๐จ๐ฆ๐๐ฌ (benign tumours of the vessels), as well as the malignant varieties of each. Ptaquiloside has also been shown to damage cells in the bone marrow, most notably the cells that produce ๐ฉ๐ฅ๐๐ญ๐๐ฅ๐๐ญ๐ฌ, the bodyโs major clotting cell. This leads to ๐ญ๐ก๐ซ๐จ๐ฆ๐๐จ๐๐ฒ๐ญ๐จ๐ฉ๐๐ง๐ข๐, or low platelet count.
๐๐ก๐ฒ ๐ข๐ฌ ๐ญ๐ก๐ข๐ฌ ๐ ๐ฉ๐ซ๐จ๐๐ฅ๐๐ฆ?
The thrombocytopenia from bracken fern toxicity prevents adequate blood clotting, leading to hemorrhages throughout the body and excessive bleeding after injury. A common site to see these hemorrhages is the bladder, which can be associated with ๐ก๐๐ฆ๐๐ญ๐ฎ๐ซ๐ข๐ (blood in the urine). These animals may become ๐๐ง๐๐ฆ๐ข๐ (low red blood cells) due to blood loss. If tumours develop, the animal may experience clinical signs related to the location of the tumour. For example, tumours affecting the throat may interfere with eating.
๐๐จ๐ฐ ๐ข๐ฌ ๐ข๐ญ ๐๐ข๐๐ ๐ง๐จ๐ฌ๐๐?
Diagnosis is typically based on identifying characteristic lesions at necropsy, combined with a history of scarce food sources or pastures contaminated with bracken fern.
๐๐จ๐ฐ ๐ข๐ฌ ๐ข๐ญ ๐ญ๐ซ๐๐๐ญ๐๐? ๐๐จ๐ฐ ๐ข๐ฌ ๐ข๐ญ ๐ฉ๐ซ๐๐ฏ๐๐ง๐ญ๐๐?
Unfortunately, there is no specific treatment for bracken fern toxicity. Animals with anemia may receive a blood transfusion, however this is usually cost-prohibitive for producers. Prevention primarily involves removing animals from affected pasture and herbicidal treatment.
๐๐ก๐จ๐ญ๐จ๐ฌ
1) What bracken fern looks like!
2) A very hemorrhagic bladder from bracken fern.
3-5) Examples of tumours in the ๐ฉ๐ก๐๐ซ๐ฒ๐ง๐ฑ (throat), rumen and bladder from bracken fern toxicity.
๐๐จ๐ฎ๐ซ๐๐๐ฌ
Maxie, G. Jubb, Kennedy and Palmerโs Pathology of Domestic Animals, Volume 2. Sixth Edition.
Stegelmeier BL. Bracken fern poisoning in animals. Merck Veterinary Manual 2016.
Photos 1-5 ยฉ Noahโs Arkive contributors Robinson, Barros, Ramos-Vera, Mendes licensed under CC BY-SA 4.0.
