Poison parsnip is found all over the United States and in parts of the United Kingdom. The most common place to find this deadly weed is by lakes and streams. Several children have been killed from using the hollow stem as a whistle and cattle have died from drinking water where the poison parsnip is growing. The poison parsnip can grow up to eight feet tall with a purple stem and jagged green leaves. The small white flowers grow in clusters that are shaped like umbrellas. Sometimes, the poison parsnip is mistaken for the edible parsnip, which is what causes many deaths in humans. It is also used by some to commit suicide because of the quick way it causes death.

Poison parsnip is the deadliest plant in the United States according to experts. Consumption of this plant is almost always fatal, causing an interruption of the central nervous system within minutes. The toxic substances in the poison parsnip are circutol, cicutoxin, and coniine. They are all in a group of polyacetylenes which depolarize the neurons by blocking the potassium in the central nervous system, causing seizures and death. These toxic properties are lethal even in small doses. If you believe your pet has eaten any part of a poison parsnip, do not wait for an appointment to see your veterinarian. Take your dog to the veterinary clinic or hospital immediately.

The signs of poison parsnip poisoning can vary, depending on the amount eaten, but if you notice symptoms, you need to transport your dog to a veterinarian right away. Some of the side effects are:

The scientific name of poison parsnip is Cicuta maculate from the Apiaceae family. It is also known by these other names:

The cause of poison parsnip poisoning is the consumption of any plant in the Cicuta family. It only takes three leaves to kill a large dog or a child and the roots are so toxic that just drinking the water around a poison parsnip plant can be lethal to your pet. There are several toxic properties in the poison parsnip, which are:

When you take your pet to the animal hospital or clinic, it is a good idea to bring a picture or a sample of the plant so the veterinarian can determine exactly what toxins are in your dog’s system. Also, bringing your dog’s medical records can be a big help in deciding what treatment to use. Be sure to tell the veterinarian if your dog is on any medications because this can mask some symptoms and may also interact negatively  with whatever treatment the veterinarian wants to use.

In some instances, therapy will be initiated before the diagnosis takes place, particularly if you are certain that your pet ingested a poisonous plant. When the exam does take place it may include weight and height, temperature, blood pressure, oxygen level, breath sounds, pulse, and respiratory rate. Some laboratory tests that may be done are a complete blood count, blood chemistry profile, liver enzyme panel, urinalysis, and blood urea nitrogen (BUN). An electrocardiogram (EKG) will also be done to check the muscle and electronic functioning in the heart. In addition, x-rays, and an ultrasound may be needed to take a look at the heart muscle and to check for obstructions. If a better look is needed, an MRI or CT scan can be performed.

Treating poison parsnip poisoning is done like all other poisonings, but with a more urgent attitude because time is essential to success. The veterinarian will probably already have hooked your pet up to an intravenous (IV) line and may also take steps to rid the body of the toxic chemicals.

The veterinarian will administer an emetic medication if your dog has not already started vomiting. An activated charcoal will also be given by mouth to absorb any undigested toxins.

To detox your pet, a gastric lavage will be performed right after the charcoal. This procedure is done by inserting a tube into the digestive tract to rinse away any lingering plant particles. Afterward, intravenous (IV) fluids will be continued to flush the kidneys and help with dehydration from vomiting and diarrhea.

An anti-seizure medication such as phenobarbital will be given to control the seizures. There is no antidote, so any medications will be supplemental damage control and support.

The veterinarian will almost certainly put your dog in the hospital for at least 24 hours, but this depends on the severity of the symptoms.

Be sure to set up a safe and quiet place for your dog to sleep for the first few days. If your pet would rather run around as usual, it may be necessary to administer sedatives or use cage training until it is safer. Watch for any signs of complications like fever, uncontrollable vomiting, and extreme lethargy. Call your veterinarian if you have any concerns about your pet’s rate of recovery, such as appetite, toileting habits, and general demeanor.