If you love fiddleheads, don’t share them with your rabbit since most of them are high in thiaminase that will breakdown vitamin B1, carry pathogens, and some like ostrich fern and bracken (genus Pteridium)are poisonous or toxic.
What are they?
Fiddleheads or fiddlehead greens refer to the curled or rolled fronds of young ferns used as a vegetable. Usually, harvesting happens before they unroll or grow to their full height.
There are some Nepalese, North America, Indian cuisines, Asian cuisine that cook these vegetables. Also, you can pickle them. The commonly eaten ones are Bracken and midin as well as the Western sword, Ostrich (contains some unidentified toxins), Lady, Royal, flowering (Zenmai), and Vegetable ferns.
Are they safe?
No, they are not safe and rabbits shouldn’t eat fiddleheads. We don’t recommend them unless you know the specific species or variety is safe for bunnies. Yes. We know they are rich in antioxidant-rich, have omega-3 and omega-6 fatty acids, high in potassium but low in sodium.
However, you deserve to know that most ferns are high in the enzyme thiaminase, which will break down thiamine (vitamin B1) and potentially cause a deficiency. For instance, Bracken is known to cause thiamine deficiency in pigs and horses.
Secondly, Bracken, a name for genus Pteridium ferns in the family Dennstaedtiaceae are carcinogenic. They can cause acute poisoning since it has ptaquiloside, known to damage DNA. Cattle are known to suffer from poisoning.
While proper cooking it degrades ptaquiloside, bunnies don’t eat cooked foods, meaning they may suffer from poisoning.
While they are not carcinogenic, the ostrich fern (Matteuccia struthiopteris) has a toxin that hasn’t yet been well identified.
Finally, they do carry a lot of microbes, making them potentially dangerous to your furry friends.
Conclusion
The reasons why we don’t recommend them are apparent. Therefore, before you give your bunny any fiddleheads, ensure they don’t contain thiaminase, are not carcinogenic, or don’t have any other toxins.
If you are unsure, don’t give them. Also, don’t let them graze in areas that have fiddleheads or any other unsafe ferns.