Lupines (Lupinus species) are a genus of flowering plants comprising hundreds of species, including both wild natives and cultivated hybrids popular in gardens. They are easily recognized by their tall, showy spikes of pea-like flowers, which bloom in a wide array of colors including blue, purple, pink, white, and yellow. Their leaves are typically palmately compound, meaning multiple leaflets radiate from a central point like fingers on a hand. In the United States, common garden varieties are often hybrids (Lupinus polyphyllus), while the Texas Bluebonnet (Lupinus texensis) and Sundial Lupine (Lupinus perennis) are well-known native species. It is important for pet owners to correctly identify these plants in their gardens or on walks, as all parts of the plant contain compounds that can be harmful.
The primary toxic principles in lupines are a group of alkaloids, which are nitrogen-based organic compounds produced by the plant as a natural defense mechanism against herbivores. The specific type and concentration of these alkaloids can vary significantly between different lupine species and even within the same species based on factors like soil conditions, climate, and stage of growth. Some modern ornamental hybrids have been selectively bred to have lower alkaloid levels, but they are not considered safe. The most concerning alkaloids are those that can cause neurological effects. Additionally, the seeds and seed pods contain the highest concentrations of these toxic compounds, especially as the plant matures.
All parts of the lupine plant are considered toxic to pets, including dogs, cats, and horses. The seeds and seed pods pose the greatest threat due to their high alkaloid content. When ingested, these compounds can negatively affect the nervous system and the gastrointestinal tract. The toxicity is dose-dependent, meaning a large dog would need to consume a larger quantity to show severe signs compared to a small dog or cat. However, even small amounts can cause unpleasant symptoms. It is crucial to prevent pets from chewing on any part of the plant, particularly when it is setting seed. Furthermore, the plant material can potentially cause a mechanical obstruction in the digestive tract if consumed in large pieces.
The symptoms of lupine poisoning typically appear within an hour of ingestion but can be delayed. The effects are primarily neurological and gastrointestinal. Key signs to watch for include: lethargy, excessive drooling, vomiting, and diarrhea. More severe neurological signs can involve loss of coordination, tremors, seizures, and depression. In the most critical cases, especially with large ingestions, respiratory depression and coma can occur. It is worth noting that some lupine species, if consumed by pregnant animals, can cause congenital deformities known as "crooked calf disease" in livestock, though this is a greater concern for large animal owners than typical pet owners.
If you suspect your pet has ingested any part of a lupine plant, immediate action is required. First, safely remove any plant material from your pet's mouth. Do not induce vomiting unless specifically instructed to do so by a veterinarian or animal poison control expert, as this can sometimes cause more harm. Contact your veterinarian or the ASPCA Animal Poison Control Center (888-426-4435) immediately for professional guidance. Be prepared to provide information about the plant, the amount you believe was ingested, and your pet's current weight and symptoms. Treatment is primarily supportive and may include inducing vomiting by the veterinarian, administering activated charcoal to bind the toxins, and providing intravenous fluids and medications to control seizures or nausea.
