Are Larkspurs Poisonous to Dogs?

Larkspur Toxins

• Like other members or the Buttercup (Ranunculaceae) family, larkspurs contain toxic diterpene alkaloids. While livestock are more vulnerable to these poisons than dogs, your pet still faces some very serious consequences if he munches on the plants. The California Poison Control system rates larkspurs' toxicity as Level 4, saying they're capable of causing serious organ damage. The age of the plant, amount your pet consumes and parts he eats all factor into the severity of his reaction. The good news is that most dogs usually ignore larkspurs.

Signs of Larkspur Poisoning

• United States Department of Agriculture researchers, examining the effects of larkspur consumption in cattle, found that larkspur prevents the neurotransmitter acetylcholine from reaching receptors in the brain and muscles. Affected animals struggle to breathe, developing irregular, rapid heart rates and muscular weakness before collapsing. The American Society for Prevention of Cruelty to Animals reports that dogs with larkspur poisoning may have all these symptoms, as well as stiffness, convulsions and digestive problems, including vomiting and constipation. Worst-case larkspur poisoning causes heart or respiratory failure.

Responding to the Emergency

• If you discover Fido snacking on the larkspurs, don't wait for him to exhibit symptoms of poisoning. Get him away from the plants and call your veterinarian, the ASPCA or a pet poison helpline. Remove any bits of the plant still in his mouth and give him a small amount of water if he wants it. Don't attempt to treat him yourself; take him to an animal hospital as soon as possible and bring along the larkspur. If he's still conscious, the doctor will induce vomiting before determining a course of treatment. If he's unconscious, he'll need oxygen and IV fluids or other support therapies to manage his symptoms.

Avoiding the Problem

• If your pooch loves wandering free in the garden, but the possibility of his making a deadly meal of the larkspurs is significant, your best option is to replace the plants. One suitable and nontoxic alternative is annual China aster (Callistephus chinensis). This annual blooms from early summer to fall, filling the border with masses of white, pink, yellow, red, blue or purple. As an added bonus, its cheery, 3-to-5-inch daisy or pompom flowers draw crowds of butterflies.