Lobelia Poisoning in Dogs

Lobelia poisoning occurs when your dog consumes parts of the lobelia plant and is exposed to lobeline, the plant’s toxic principle. In terms of its toxicity level, lobelia is rated a major toxin. This means that ingestion of the plant can be the cause of serious consequences which may be fatal. Also, the various parts of this plant can result in dermatitis that can be painful and cause your pet much distress. If you see your pet ingesting this plant, seeking veterinary care is advised. Pets should always be evaluated after consuming a plant that you are unfamiliar with due to the potential for poisoning after exposure.

Lobelia (Lobelia cardinalis), which is of the family Campanulaceae and is also known as Indian pink and cardinal flower, is one of many plants that are poisonous to dogs when ingested.

Clinical signs that are associated with lobelia poisoning will typically become apparent within 24 to 48 hours after a dog consumes the plant. 

Initial symptoms include:

• Diarrhea
• Vomiting
• Excessive salivation and drooling
• Nasal discharge
• Drooping ears
• Extended neck
• Esophageal irritation
• Painful and tender abdomen

Also, the thorns, sap, and juice of the lobelia plant can cause skin irritation and damage to the mucous membranes upon exposure.

If not treated promptly, a dog’s symptoms will become more severe as the poisoning progresses. This can occur in a matter of hours, and the symptoms can include:

• Depression
• Dilated pupils
• Lack of appetite
• Exhaustion
• Weakness
• Collapse
• Disturbances in heart rhythm
• Shallow, difficult breathing
• Extremely weak pulse
• Convulsions
• Paralysis of limbs
• Cardiac arrest and death (may happen within hours of the first symptoms or within days)

Types   

Toxic plants within the lobelia genus include:

• Lobelia cardinalis (cardinal flower)
• Lobelia inflata (Indian tobacco)
• Lobelia siphilitica  (great lobelia)

In all three cases, the entire plant is toxic.

• Ingestion of any part of a plant within the lobelia genus

Many pet owners may not realize that their dog has consumed a potentially deadly dose of the lobeline compound in lobelia. They only become aware of the fact that something is wrong after their dog develops clinical symptoms. With exposure to the lobelia plant, do not wait for symptoms to appear before contacting the veterinarian.

While it’s rare that a dog would consume a fatal amount of lobeline because this plant also has emetic properties that induce vomiting, a dog could ingest a large portion of the plant and develop fatal symptoms within hours or days.

When a pet owner sees their dog eating a lobelia plant, a veterinarian will be able to diagnose the pet’s condition based upon the identification of the plant and the symptoms that it has caused. If possible, bring the plant that your dog was eating with you to the veterinarian’s office so that an accurate diagnosis can be made. 

If you aren’t certain about whether or not your dog consumed lobelia or any other plant, the veterinarian will require your pet’s medical history, along with any information regarding the potential that your dog could have consumed a poisonous plant. If you are able, take note of the time lapse between ingestion of the plant and the veterinary appointment.

The order of the testing will be contingent on the condition of your dog when he arrives at the clinic. The veterinarian will likely order a complete blood count, biochemistry profile, urinalysis, and other tests to determine the functionality of organ systems throughout the body and to determine the level of poisoning. The condition of the heart will be important, and can be determined through imaging tools.

Prompt treatment is necessary to help a dog recover after ingesting lobelia. If a dog is seen eating any plant of the lobelia genus, he should be stopped immediately and treated by a veterinarian right away. Whether a dog is seen consuming lobelia, or symptoms of poisoning have developed, prompt veterinary treatment is necessary to save the animal’s life. 

Veterinarians do not have an antidote for lobelia poisoning in dogs. Treatment will prioritize stabilising your dog and ridding the body of the toxins. If only a small amount of lobelia was ingested, the veterinary team will likely induce vomiting, especially if a pet owner can confirm that they saw the dog eating the plant. Activated charcoal can also be used to neutralize the lobeline and further bind the toxins remaining in your dog’s stomach. However, your dog will need to remain under a veterinarian’s care to watch for symptoms of neurological distress such as paralysis. 

If a large amount of lobelia was ingested, or your dog consumed small amounts over a period of days, and if advanced symptoms have manifested, the veterinary team will provide respiratory support and treatment for shock. Vomiting will be induced, and a gastric lavage may also be used, along with the administration of activated charcoal. 

Phentolamine and atropine can be given intramuscularly or intravenously to control sympathetic or parasympathetic hyperactivity. Also, propranolol can be used to treat cardiac arrhythmias. Dogs that are experiencing convulsions may have to be sedated. Because the main cause of death associated with lobelia poisoning is respiratory paralysis, especially when a large amount of the plant has been consumed, your pet will be given oxygen support to help him breathe and intravenous therapy for the administration of medications until the body is able to detoxify naturally and danger has passed.

If your dog only consumed a small amount of lobelia, a full recovery is possible with the appropriate treatment within a few hours. The veterinarian will determine when your  dog’s toxicity level has dropped to a safe enough level to be discharged. After discharge, the veterinarian may suggest a bland diet for your dog for a few days, and plenty of rest before returning to daily activity. Removal of the lobelia plant from your home or garden may be recommended, especially if your pet has an appetite for flowers and greenery.