Are Macho and Sword Ferns Toxic to Dogs?

Name: Are Macho and Sword Ferns Toxic to Dogs?
Creator: Dr. Zubair Khalid

By Dr. Zubair Khalid, DVM, MS, PhD · 2026-10-03

Is macho fern toxic to dogs? No. The ASPCA Animal Poison Control Center lists sword fern (Nephrolepis biserrata), which is sold under names like macho fern and bold sword fern, as non-toxic to dogs, cats, and horses [1][2]. That means the plant itself does not contain a known poison that harms dogs. A dog that chews a frond may still drool, gag, or vomit from the plant material itself, but that is irritation, not poisoning.

This article is educational and is not a substitute for veterinary diagnosis or treatment.

Quick Answer

Macho fern and sword fern are the same species, Nephrolepis biserrata, and both are listed as non-toxic to dogs [1][2].
No toxic principle is listed for sword fern, so there is no poison dose to calculate [1].
Eating fronds can still cause mild mouth irritation, drooling, vomiting, or diarrhea from the fibrous plant material.
If your dog ate a small amount and seems normal, watch it at home and call your veterinarian with any questions.
If your dog has repeated vomiting, trouble breathing, or swelling of the face or throat, treat it as an emergency and call your veterinarian or a poison control line right away.

Is Macho Fern Toxic to Dogs?

No. Macho fern is a common trade name for sword fern, and the ASPCA plant record for sword fern lists it as non-toxic to dogs, cats, and horses [1]. A separate ASPCA record for bold sword fern, same scientific name Nephrolepis biserrata, also lists it as non-toxic to dogs, cats, and horses [2]. Both records belong to the same plant, so you can treat macho fern and sword fern as the same answer for your dog.

This is good news for households with ferns on the patio or in a bright window. Many popular ferns are safe, and sword fern is one of them. If you want a broader list of plants that will not poison your pets, see Plants That Aren't Toxic To Cats And Dogs.

Which Parts of the Plant Are Involved?

The whole plant is considered non-toxic, including the fronds, the stems, and the root ball [1][2]. There is no part of sword fern that carries a known poison for dogs. That does not make it food. Fern fronds are tough and fibrous, and a dog that swallows them can still get an upset stomach.

What About Fertilizers, Pesticides, and Potting Soil?

The plant is not the only thing in the pot. Fertilizer spikes, systemic insecticides, and slug bait can be far more dangerous than the fern. If your dog chewed a treated plant, the risk depends on the product, not the fern. Call your veterinarian or a poison control line and have the product label ready.

Is Sword Fern Toxic to Dogs?

No. The ASPCA lists sword fern as non-toxic to dogs, cats, and horses, with no toxic principles and no clinical signs listed [1]. The same is true for bold sword fern [2]. So if your dog nibbled a sword fern frond, the plant itself is not a poison.

The word "fern" covers a huge group of plants, and not all of them are safe. Bracken fern (Pteridium species) is a genuinely dangerous plant in livestock. In cattle, bracken fern consumption is linked to upper digestive tract squamous cell carcinomas, and it also causes a bleeding disorder tied to ptaquiloside [3][4]. Those findings come from cattle grazing on bracken fern, not from dogs eating a houseplant, but they show why "fern" alone is not a safe answer. Know the species, not just the common name.

If you are sorting through other plants in your home, Plants Poisonous To Dogs covers the ones that actually cause harm.

The Toxic Principle and What It Does in the Body

Sword fern has no toxic principle listed by the ASPCA [1]. There is no known compound in this plant that damages a dog's organs, nerves, or blood. That is the main reason it sits on the non-toxic list.

When a dog eats a fern frond, the effects come from the plant material itself. Chewing rough fibers can scrape the mouth and throat, which triggers drooling and lip licking. Swallowed fronds can sit heavy in the stomach and cause vomiting or loose stool. In most cases the body moves the material through and the signs settle.

Some plants cause harm through specific mechanisms. Bracken fern contains ptaquiloside, which predisposes animals to bleeding and hemorrhage, and it has been linked to cancer in cattle that graze on it for long periods [3][4]. Other plants damage red blood cells directly and cause anemia [4]. Sword fern does not work this way. There is no evidence that it causes anemia, bleeding, or cancer in dogs.

One more note on the word "fern." Tear ferning is a laboratory pattern seen when a dog's tear sample dries on a slide, and it is used to assess tear film quality in dry eye [5]. It has nothing to do with eating plants. If you see "ferning" in a veterinary report, it is about tears, not ferns.

Signs to Watch For and Typical Timeline

Most dogs that chew a sword fern have no signs at all. When signs do appear, they are usually mild and start within minutes to a few hours of eating the plant.

Watch for:

Drooling or lip smacking
Gagging or retching
Vomiting once or twice
Soft stool or diarrhea
Reduced appetite for a meal or two
Pawing at the mouth

These signs usually fade within a few hours to a day as the plant material passes. Call your veterinarian if vomiting repeats, if your dog stops eating, or if you are unsure how much was eaten.

Some signs point to something else entirely. Facial swelling, hives, trouble breathing, collapse, or a racing heart are not typical of sword fern and need emergency care. If your dog ate a different plant, a fertilizer, or a bait, the timeline and signs can be very different. Bring the plant or label with you.

What to Do Right Now

Stay calm and take stock. Identify the plant if you can, and estimate how much your dog ate. A photo of the plant or a cutting in a bag helps your veterinarian.

Call for advice. You can reach your veterinarian, the ASPCA Animal Poison Control Center at (888) 426-4435, or Pet Poison Helpline at (855) 764-7661. A consultation fee may apply to poison control calls. If the plant is confirmed sword fern and your dog is bright and comfortable, many cases can be managed at home with monitoring.

Do not induce vomiting unless a veterinarian tells you to. Making a dog vomit can cause harm if the material is sharp, if the dog is already struggling to breathe, or if the wrong substance was eaten. Let your veterinarian make that call.

Offer small amounts of water. Do not push food if your dog is vomiting. Keep the plant out of reach while you watch your dog.

Veterinary Treatment for Fern Ingestion

Treatment depends on what your dog actually ate and how it looks. For a confirmed sword fern nibble with mild signs, your veterinarian may simply recommend monitoring at home and a bland diet for a day.

If your dog is vomiting or uncomfortable, your veterinarian may give fluids under the skin or into a vein, an anti-nausea medication, and a stomach protectant. Any medication dose is calculated from your dog's weight and health, so it is set by your veterinarian, not by a home guess.

If the plant is unknown or a toxic species is possible, your veterinarian may run blood work, take x-rays, or use charcoal to bind a poison. Some poisons need specific antidotes. As one example, dogs with para-aminopropiophenone toxicity, a bait poison, were treated with intravenous methylene blue at a mean initial dose of 3.8 mg/kg in a case series of 13 dogs [6]. That drug and dose apply to that specific poison, not to ferns, and only a veterinarian can decide if it is needed.

Outlook for a Dog That Ate Macho Fern

The outlook is excellent for sword fern. Since the plant is non-toxic, most dogs recover fully with no treatment beyond a little rest and water [1][2]. Mild stomach upset from plant fiber typically passes within a day.

The outlook changes if the dog ate something else in the pot or yard. Fertilizers, insecticides, rodenticides, and toxic plants can cause serious illness. That is why identifying the plant and any products on it matters more than the fern itself.

Prevention and Safer Alternatives

You do not need to rehome your macho fern. You do need to keep your dog from treating it as a salad bar, mostly to avoid stomach upset and to protect the plant.

Place ferns on a stand or hanging basket out of reach.
Rinse leaves if you use foliar fertilizer, and keep fertilizer spikes buried and covered.
Store bait, insecticides, and fertilizer in closed containers away from pets.
Train a "leave it" cue and offer safe chew toys instead.
Check any new plant against a reliable list before you bring it home.

If you like the look of ferns, sword fern is a reasonable choice for a pet household [1][2]. For other safe options, browse Plants That Aren't Toxic To Cats And Dogs. If you are also wondering about non-plant hazards around the house, Are Tarantulas Poisonous to Dogs? Understanding the Risks answers a common question.

Limitations and When to Contact a Veterinarian

This article covers sword fern and macho fern only. It cannot tell you what your dog ate, how much, or how your dog will respond. Individual cases need a veterinarian who can examine your dog and ask about the details.

Contact your veterinarian the same day if your dog:

Vomits more than once or vomits for more than a few hours
Has diarrhea that does not settle
Refuses food or water
Seems dull, weak, or uncomfortable
Ate an unknown plant, fertilizer, or pesticide

Go to an emergency clinic now if your dog:

Has trouble breathing, wheezing, or noisy breathing
Has swelling of the face, lips, or throat
Collapses, faints, or has a seizure
Has a racing or irregular heartbeat
Has pale, white, or yellow gums
Is bleeding from the nose, mouth, or rectum

Schedule a routine visit if signs were mild and resolved but you want your dog checked, or if you need help pet-proofing your home.

Frequently Asked Questions

Is macho fern toxic to dogs?

No. Macho fern is a trade name for sword fern, Nephrolepis biserrata, and the ASPCA lists it as non-toxic to dogs, cats, and horses [1][2]. A dog that chews it may have mild stomach upset from the plant fiber, but the plant is not a poison.

Is sword fern toxic to dogs?

No. Sword fern is listed as non-toxic to dogs, with no toxic principles and no clinical signs listed [1]. The same record applies to bold sword fern under the same scientific name [2].

What happens if my dog eats a fern frond?

Most dogs have no signs or only mild drooling, gagging, or one episode of vomiting. The fibrous frond can irritate the mouth and stomach, and signs usually settle within a few hours to a day. Call your veterinarian if vomiting repeats or your dog seems unwell.

Are all ferns safe for dogs?

No. Ferns are a large group, and some, like bracken fern, are linked to serious disease in livestock, including bleeding disorders and upper digestive tract cancer in cattle [3][4]. Always identify the exact species before you assume a fern is safe.

Should I make my dog vomit after eating a fern?

No, not unless a veterinarian tells you to. Inducing vomiting can cause harm, and it is not needed for a non-toxic plant like sword fern. Call your veterinarian, the ASPCA Animal Poison Control Center at (888) 426-4435, or Pet Poison Helpline at (855) 764-7661 for guidance.

References

Toxic and Non-toxic Plants: Sword Fern. ASPCA Animal Poison Control Center.
Toxic and Non-toxic Plants: Bold Sword Fern. ASPCA Animal Poison Control Center.
Bovine upper alimentary squamous cell carcinoma associated with bracken fern poisoning: Clinical-pathological aspects and etiopathogenesis of 100 cases. PloS one, 2018.
Anaemia in Ruminants Caused by Plant Consumption. Animals : an open access journal from MDPI, 2022.
Tear ferning in normal dogs and dogs with keratoconjunctivitis sicca. Open veterinary journal, 2017.
Para-aminopropiophenone toxicity in domestic dogs: a description of non-target toxicosis in Victoria, Australia: 13 dogs (2016-2023). Australian veterinary journal, 2025.