There are a few types of sweet pea plants; the Lathyrus latifolius is a perennial climbing vine which can over six feet, the Lathyrus odoratus is an annual that grows to the same height, and the Lathyrus sativus which is a smaller perennial that is grown for food in countries where food and rain are scarce. Any of these plants can be considered toxic to your dog, cat, or other small animals.

Although they sound like they should be edible, sweet pea plants are not food. As a matter of fact, they contain the toxic chemical called aminoproprionitrile, which causes musculoskeletal and central nervous system problems. If these pretty little plants are eaten repeatedly, a complication called lathyrism will be created, including the above symptoms as well as muscle weakness, paralysis, and it can even be lethal. One type of the sweet pea that is considered edible (Lathyrus sativus) can be dangerous if it is the main form of protein. In a study done with thousands of rats, it was found that when eating a diet that is at least 50% sweet pea seeds, the rats developed swollen adrenal glands with marked lethargy (tiredness), pacing, and more.

Sweet pea poisoning symptoms are varied, depending on the type of plant and how much was eaten. In addition, the symptoms of sweet pea poisoning may not show up for several days, making it hard to determine what is making your dog sick unless you actually witnessed your dog eating the plant. The most often reported symptoms are:

 Types

The sweet pea plant (Lathyrus latifolius or Lathyrus odoratus) is from the Fabaceae family, order of the fabales, and lathyrus genus. There are several varieties and other common names for the sweet pea, which are:

As with any type of suspected poisoning, try to take a portion of the plant to show the veterinarian for a faster definitive diagnosis. An intravenous (IV) line will be started to provide fluids while you give your veterinarian all the information on the incident and whether there have been any symptoms yet. The IV fluids will flush the toxins through the body faster and prevent dehydration. A brief medical history including your dog’s vaccination records, any strange behavior, previous illness, recent injuries, medication, and appetite changes can be very helpful in getting the best medical treatment. A physical examination will be done to check your dog’s overall health, reflexes, weight, temperature, respiration and pulse rate, blood pressure, breath sounds, and oxygen saturation levels.

The usual round of laboratory tests for this situation include a urinalysis, fecal examination, biochemistry profile, electrolyte panel, complete blood count (CBC), blood gas levels, glucose levels, and blood urea nitrogen (BUN). An electrocardiogram (ECG) may need to be done to monitor your dog’s heart muscle and electronic function while waiting for the other test results. The veterinarian may also want to get chest and abdominal x-rays as well to check pulmonary (lung), kidney, and liver function. If a more detailed view is needed, an MRI, CT scan, or ultrasound can be done.

To keep flushing out the toxins, IV fluids will be continued and oxygen will be given to your dog if needed. In addition, the veterinarian will try to induce vomiting with a hydrogen peroxide solution to rid the body of as much toxins as possible. Activated charcoal will also be given to absorb whatever poisons are left. If your dog has been having seizures, the veterinarian will administer an anti-seizure medication such as phenobarbital, and your canine companion will be kept at the hospital overnight for observation.

Once your dog is able to go home, it is essential to provide a safe and quiet place to rest. If your dog is acclimated to a cage, this is the best way to provide such rest safely, particularly if your dog is very active. If your dog gets too much exercise it could cause a relapse and the symptoms may return, making it necessary to visit the veterinarian again. To prevent this type of poisoning from happening another time, it is recommended to remove any sweet pea plants from either inside or outside your home. If that is not possible, make sure your dog is unable to access the flowers at any time.