Flax Poisoning in Dogs

Flax, also known as common flax or linseed, is grown for a variety of purposes. Fibers from the stem have traditionally been used to make linen; the seeds are processed to make flax meal and oil which is used as a health supplement as well as for some commercial purposes; flax can also be grown as a garden flower. Cultivated flax, Linum usitatissimum is a member of the Linaceae family. It grows about 4 feet (1.2 meters) high with sky blue flowers and a dry round fruit that contains the well-known flax seeds. 

Health supplement made from flax are high in Omega-3 and Omega-6 fatty acids. They are believed to reduce the risk of cancer, help heal inflammation, and improve digestive health. Some veterinarians recommend flax supplements for dogs, however there are several things dog owners should consider. Flax seed oil contains more Omega-3 fatty acids than fish oil, but it is in a form that is less accessible to dogs. ALA (alphalinolenic acid) in flaxseed oil must be converted to active Omega-3’s (EPA and DHA) to have an anti-inflammatory effect. There is currently no reliable proof that dogs can metabolize ALA, so fish oil (which already has available Omega-3’s) is still considered more effective than flax for treating dogs with chronic inflammation from arthritis or allergies. The other component in flax oil, Omega-6 fatty acids, can improve the health of your pet’s coat, however most pet foods do already contain some Omega-6 supplements. 

Additionally, the raw flax plant contains cyanogenic glycosides, so large amounts could result in cyanide poisoning. Processing removes the toxic component, so this is typically only a problem when raw flax meal is used to feed livestock. The FDA and Mayo-Clinic support the safety of flax supplements for humans, within the recommended dosage; however the FDA does not regulate health supplements, so care should be taken to read packaging and research specific products. Recommended doses of flaxseed oil for dogs range from about 1 teaspoon per day for a small dog to 1 tablespoon for a large dog, but you should discuss the best product and dose range for your dog with a veterinarian before beginning treatment. 

If your dog overdoses on flaxseed supplement, the adverse effects will typically be limited to vomiting and diarrhea, mainly due to the body’s inability to metabolize that much oil. However, very large amounts could result in poisoning from trace elements of cyanide that were not removed with processing. This is especially true if your dog is very small or has another medical condition that makes it harder for the body to eliminate toxins. Consumption of the raw plant from a garden could also have negative effects, although it would take a large amount to produce significant toxicity. Dermatitis and skin irritation may be associated with topical contact.

The flax plant contains low levels of cyanide producing compounds that make it toxic in large doses. Toxin levels can vary based on variety, season and climate. Cyanogenic glycosides are destroyed with processing, so flax oil and other supplements are safe for dogs, however overdose will still have negative symptoms.

These are some of the symptoms you may see if your dog overdoses on flax. (Extreme symptoms have been produced during research studies).

• Vomiting
• Diarrhea
• Shortness of breath
• Rapid heart rate (tachycardia)
• Weakness
• Trouble walking
• Seizures
• Paralysis

Types

There are a number of different flax products.

• Whole processed seeds are the most storable form the seeds will most likely be passed through a dog’s system without digestion
• Oil is the most concentrated source of flax, must be refrigerated to avoid spoilage
• Processed flax meal is ground flax seeds and a source of fiber, must be refrigerated to avoid spoilage
• Raw unprocessed flax seed or meal are most likely to cause toxicity.
• With the flax plant, topical contact can cause skin irritation and dermatitis, adverse effects if ingested in large amounts

These factors increase the risk of flax poisoning.

• Owner mistakenly giving their dog too much of a flaxseed supplement
• Dog chewing open a bottle of capsules or oil
• Improperly processed supplement
• Ingesting raw flax
• Flax plants growing in the garden

If you dog ingested a large amount of flaxseed oil, give him some dry dog food help to reduce the oil concentration in the stomach. Vomiting may be induced to limit absorption, but only upon the recommendation of a professional. Mild overdoses won’t require further treatment.

A veterinarian will be able to induce vomiting more safely and effectively than you can at home. If cyanide poisoning is present, immediate treatment will be necessary. Sodium nitrate and sodium thiosulfate will be given as an antidote as well as additional oxygen to supplement breathing.

If your dog has dermatitis from contact with the raw plant, gently wash the affected area. Topical ointments could be necessary for extreme symptoms. Call a veterinarian if the plant is ingested. Most cases won’t require treatment unless there are severe symptoms.

Most dogs will recover from flax poisoning. The risk of cyanide toxicity is more likely if raw flax products are consumed, but it remains extremely rare. Many common foods like almonds, cassava, and soy products contain low levels of cyanide producing compounds, but they can still be consumed safely since it would take such a large amount to have any significant toxic effect.

Flax supplements are typically safe for dogs, although there is still some debate about their effectiveness. It’s not advisable to use these products without the recommendation of a veterinarian. In order to avoid accidental overdose, store all supplements and medications on a high shelf or in a closed cupboard your dog cannot access.