Poison Hemlock Poisoning in Dogs

Poison hemlock is an herb that resembles parsley. Poison hemlock is often confused for parsley because, it to, has a purplish stem that is smooth and hollow similar looking leaves. Poison hemlock may be also mistaken for water hemlock, although they have a different root systems and leaves. This herb can grow up to 6 feet tall and is adorned with white flowers in the summer. Perhaps poison hemlock gets its name from the leaves, which are excruciating to the taste buds and contain piperidine alkaloid poisons known as coniine.  Coniine is highly similar to nicotine.

Poison hemlock came to the North American continent from Europe. This plant is very hardy; however, does not grow as well in high temperature areas. Poison hemlock is found in various locations in the United States, namely around water areas such as streams and small rivers. It can also be found on riverbanks, in fields, and in other undisturbed areas.

Poison hemlock poisoning in dogs is a result of dogs ingesting any quantity of the poison hemlock plant. This plant contains coniine, which is a toxic substance similar to nicotine.

If your dog has eaten poison hemlock, symptoms may vary depending on the amount ingested. Symptoms of poison hemlock toxicity include:

• Abnormal hyperactivity or excitement
• Seizures
• Collapse
• Muscle spasms
• Shaking
• Drooling
• Urination
• Pain in the abdomen
• Vomiting
• Diarrhea
• Increased heart rate
• Respiratory system excitement

Types

Piperidine alkaloids are present in poison hemlock, and other plants as well. Plants that contain coniine, similar to nicotine include:

• Hemlock
• Yellow pitcher plant
• Fool’s parsley
• Tobacco plant (nicotine)

Piperidine alkaloids are also present in other plants that have different names. Other names for poison hemlock are:

• Spotted hemlock
• Winter fern
• Nebraska fern
• Deadly hemlock
• Poison parsley

Causes of poison hemlock poisoning are the chemicals in the plant. Coniine, N-methylconiine, and conhydrine are found within the Poison hemlock. The causes of poisoning by coniine are:

• The negative effects coniine has on the central nervous system
• Antagonistic interactions with various receptors of the nervous system
• Coniine is absorbed very quickly into the tissues and blood stream
• Coniine and other similar alkaloids can affect the liver and kidneys

If your dog ate any amount of poison hemlock, call your veterinarian as he will develop symptoms almost immediately. If you are able to do so, take a sample of the plant to the veterinarian’s office with you. Your veterinarian will assess your dog and ask you questions pertaining to the amount ingested and how long ago it happened.

Your medical professional will take samples of his blood; he may also perform a urinalysis and biochemistry profile. The veterinarian may also take a sample of the plant to be sure it is poison hemlock rather than parsley.

By looking at the tests that were administered, signs of coniine will alert the veterinarian to begin immediate treatment. Poison hemlock can be lethal if treatment is not received immediately. Even if this happens, depending on the time it took for the treatment to begin, your dog may be facing a life-threatening situation.

Treatment must begin immediately to counteract the effects of the toxins. Treatment methods may vary depending on your dog’s level of poisoning. Treatment methods include:

Emesis

Your veterinarian may induce vomiting to expel the stomach contents. This will assist in removing a portion of the coniine before it becomes absorbed by the stomach. This method of treatment will also be followed up with activated charcoal. The administration of activated charcoal may help prevent further toxicity by soaking up the poisons within the remaining contents of the stomach.

Intravenous Fluids

Due to the severity of the poisoning, your dog may have severe vomiting and diarrhea. IV fluids will help rehydrate your companion. IV fluids will also promote proper kidney function by encouraging your dog to urinate.

Sedation

If your dog is showing signs of central nervous system abnormalities, namely tremors and muscle spasms seizures, your medical professional may need to sedate him. During sedation your dog will receive oxygen therapy to help deliver oxygenated blood throughout the body which will help to  keep your dog from becoming agitated and stressed.

In terms of recovery, it is important to understand that this chemical can be fatal to dogs. Immediate treatment and whether your dog responds to this treatment will allow the veterinarian to make a prognosis. Prognosis is fair to extremely guarded, depending on the level of poisoning.

More than likely, your dog will have stayed in the hospital for a few days. If your pet is showing signs of recovery and becoming stable your veterinarian will release him and you can take him home. He will give you directions on how to properly care for your dog at home and will explain to you any symptoms of concern.

The veterinary team may also prescribe a special diet if your dog suffered from gastrointestinal distress. Large quantities of fresh water must be made available to your dog. In order to prevent future poisonings, become familiar with all of the plants within your home or on your property. It is important to learn which plants should be removed from the garden and which ones require you to monitor your dog when he is inside or outside.