Cycads Poisoning in Dogs

Cycads come in many shapes and sizes, but all resemble a palm tree and fern combined. These types of plants generally have a large trunk with fronds that are only at the top of the plant and look similar to fern fronds. Even though they look like palm trees, they are not related, and are found all over the southwestern part of the globe and into the southern United States. There are two main toxins in cycads, which are Beta-methylamino-L-alanine (BMAA), a neurotoxic amino acid which causes loss of balance, confusion, and liver damage, and cycasin, which causes gastrointestinal, hepatic, and neurological effects.

Cycads are a group of toxic plants with three families (Cycadaceae, Stangeriaceae, and Zamiaceae) and many classes, orders, and suborders with over 100 species in each. Therefore, there are a large amount of plants and trees that are considered cycads, but all of them are toxic to dogs, other animals, and even humans if eaten. Some forms of cycads are more toxic than others, depending on the amount of the toxin in the plant and seeds. The seeds are the most toxic, and just two or three can be fatal if consumed, causing liver failure, central nervous system damage, and gastrointestinal irritation. Some of the side effects are vomiting, jaundice, paralysis, convulsions, coma, and death.

The signs of cycads poisoning in dogs may show up within minutes or it may take several days, and these symptoms can last from one to nine days. The severity of the symptoms depends on the amount and part of the cycads consumed, with the seeds being the most toxic. The most often reported symptoms are:

Gastrointestinal signs

• Dark stools
• Diarrhea (sometimes bloody)
• Loss of appetite
• Nausea
• Vomiting

Neurological

• Weakness
• Depression
• Inability to control movement
• Paralysis
• Seizures
• Coma
• Convulsions

Hepatic

• Abdominal pain
• Bruising
• Abnormal bleeding and clotting
• Lethargy
• Dark urine
• Frequent urination
• Swollen abdomen (fluid retention)
• Jaundice (yellow tint to skin and eyes)
• Liver failure
• Death

Types

Cycads have many different types and species, but the most common are:

• Cardboard palm
• Coontie palm
• Fern palm
• Sago palm
• Zamia

• B-methylamino-l-alanine (BMAA) is a neurological irritant that can cross the blood/brain barrier; staying there and causing symptoms such as paralysis, muscle atrophy, and brain damage  
• Cycasin may cause gastrointestinal, hepatic, and neurological effects

Diagnosis of cycads poisoning can be made by the symptoms you have seen and what plant you believe your dog has been eating. If you are not sure what your dog ate, tell the veterinarian what plants you have both inside and outside your home. In some cases, your dog may have gotten ahold of a cycad, such as a coontie or cardboard palm tree, in another person’s yard or at the park, so the symptoms may be all the veterinarian has to go on. She will do an extensive physical examination of your dog’s overall skin and coat condition, vital statistics, breath sounds, pulse oximetry, and an abdominal palpation.

Abdominal x-rays are important to determine the extent of damage to the liver and an ultrasound to check the stomach contents and look for internal bleeding. In addition, an MRI or CT scan may be ordered to get a more detailed view of what is happening. A complete blood count and blood chemistry profile will be done to determine the levels of ammonia, blood urea nitrogen (BUN), liver enzymes, alkaline phosphatase, and bilirubin. Depending on the test results, a coagulation profile may be needed to check clotting, prothrombin, and thromboplastin times.

Your dog’s treatment plan depends on the test results and present symptoms. Most often, the veterinarian will follow the protocol of decontamination, vomiting, fluids, medication, and observation.

Decontamination

To decontaminate your dog, the veterinarian will rinse away any plant material or residue from the mouth, nose, and eye area. Washing and rinsing the coat may also be necessary to remove the toxins.

Vomiting

To encourage your dog to vomit, a peroxide solution or ipecac will be given. This will help empty the stomach contents. Activated charcoal will be administered to absorb any material that remains.

Fluid Therapy

An intravenous (IV) line will be started on your dog to administer fluids and electrolytes. This helps flush the toxins through the kidneys and prevents dehydration. A blood transfusion may be done if there are signs of liver damage.

Medication

Once the stomach contents are gone, the veterinarian will administer any medications that are needed such as antiemetics, antiseizure drugs, and intestinal protectants. Antibiotics may also be given to prevent infection. 

Observation

The veterinarian may keep your dog overnight for observation, depending on your pet’s condition. This will give the medical staff the opportunity to provide supportive treatment if needed.

If treatment was given within a few hours of ingestion, your dog has a good chance of survival. However, if the symptoms started before treatment and the liver is affected, the prognosis is guarded, and the chance of survival is about 50-50. To make sure this does not happen again, be sure to rid your home and yard of any type of cycads as well as any other poisonous plant.