Bacon, a French bulldog, likes to munch on the rhododendron bushes in the front yard of his Washington, D.C. home. His owner, Susan Rosenau, had heard that rhododendron might be toxic to dogs, but Bacon never seemed to suffer any ill effects, so she didn’t worry too much about his snack habit.
She was shocked, then, to learn that the showy shrub had the potential to cause vomiting and diarrhea, seizures, and even to affect Bacon’s heart rate and rhythm.
“Many people aren’t aware of just how toxic some of these really common plants are,” says Dr. Sharon Gwaltney-Brant, a veterinarian and board-certified toxicologist who is vice president of the Animal Poison Control Center, based in Urbana, Ill. “A rule of thumb is that the prettier it is, the more likely it is to be toxic.”
Besides rhododendrons, some of the other common ornamental plants that can be toxic, and even deadly, to pets are azaleas, cycad palms, oleander, foxglove, lily of the valley and castor bean.
The APCC, which is the only 24-hour-a-day animal poison control center in North America, received nearly 8,000 calls about potentially toxic plants in 2008. Actual poisonings are most commonly caused by Easter lilies in cats and cycad palms in dogs, Gwaltney-Brown says. Easter lilies are ubiquitous in floral arrangements, and miniature versions of cycad palms have become popular over the past five years in many parts of the country. A cat that chews on a single petal or leaf of an Easter lily can go into severe kidney failure and die without rapid, aggressive treatment. Cycad palms cause liver failure, and dogs may die within 24 to 48 hours after ingestion.
What does a pet-loving gardener need to know? Here are 10 expert tips to help keep your animals safe.
- Don’t assume that pets won’t eat a particular plant.
“Pets investigate things with their mouths,” Gwaltney-Brant says. “That’s why we see so many plant exposures. When you bring that new plant into the household, the cats are all going to go over and nibble on it, and ditto with the dogs.”
- Know the scientific names of plants in your home and yard so you can be specific when talking to poison control.
“The problem with common names is that jasmine in California is a totally different plant than what they call jasmine on the East Coast,” Gwaltney-Brant says. “Find out the scientific name and jot it down so you have it in case there is an exposure.”
- Be aware of regional plants that may not appear on poisonous plant lists.
Toxic plant lists don’t always include regional plants, says Dr. John Tegzes, a veterinarian and professor of toxicology at Western University College of Veterinary Medicine in Pomona, Calif. For instance, some varieties of hibiscus flowers are highly neurologically toxic while others are safe.
“Most hibiscus are fine, but there are a couple of varieties that are poisonous to dogs in particular, and unless you know which one that is, it can be dangerous,” Tegzes says.
- Use nontoxic gardening products. Slug and snail bait is highly attractive to dogs, but it causes tremors and seizures that can be severe and life-threatening within minutes to hours after they’ve eaten it. Instead, use Sluggo or Sluggo Plus, which uses iron phosphate and is non-toxic to dogs, cats and birds, recommends Cheryl S. Smith, author of "Dog Friendly Gardens, Garden Friendly Dogs."
To kill insects and fungi, Smith suggests a product called Phyta-Guard EC, which contains rosemary oil and clove oil rather than chemicals.
- If you do use chemical pesticides, restrict your pet’s access to the yard immediately after applying them. They are most dangerous when still wet. It takes a few hours for pesticides to dry in the sun and be absorbed by plants and soil, Tegzes says. To be on the safe side, wait 24 hours before letting your pet back into the yard.
- Avoid cocoa mulch. The concentration of theobromine — the active ingredient in chocolate that’s toxic to pets — varies depending on the processes companies use to create cocoa mulches. Because there isn’t any consistency from product to product, it’s safest not to use cocoa mulch, Tegzes says.
- Look beyond the plant itself to products made from it. People make jewelry out of all kinds of seeds, seed pods and beans.
“When I was in a clinical setting, the cases I would see with castor bean were jewelry: necklaces and bracelets that were made out of the castor beans themselves,” Tegzes says. “People would go to Mexico and buy these bracelets and dogs would chew on them and get poisoned.”
- If your pet has eaten a plant that may be toxic, don’t waste time trying to induce vomiting. Get veterinary advice immediately. People commonly overtreat pets or try to induce vomiting when it’s unnecessary or counterproductive, Gwaltney-Brant says. They also spend too much time trying to induce vomiting, especially in cats.
“We get calls from people who have spent the last two hours trying to get their pet to throw up, but the reality is, if it’s a true poisoning, we need to do something quickly. If they’ve been unsuccessful for more than half an hour, then generally I suggest they contact or take the animal in to a veterinarian.”
- Get rid of that old bottle of ipecac in your medicine cabinet. If you are advised to induce vomiting, ipecac isn’t the way to go about it. Instead, call your veterinarian to find out the correct dosage of hydrogen peroxide for your pet's size.
“Ipecac is actually quite dangerous if we use it in dogs and cats,” Gwaltney-Brant says. “Only about a third of dogs or cats will vomit from the ipecac, and if they don’t throw it up they will absorb it into their system where it can cause serious heart problems.”
- Don’t assume that after one bad experience, your pet will “learn his lesson.”
Tegzes once treated a dog poisoned by snail bait. After 11 days in the hospital, nine of them on a respirator, the dog recovered. The next day, he was back again, with the same type of poisoning. “We thought he would have learned his lesson,” the owners told Tegzes.
“Dogs love to eat that stuff once they’ve tasted it, so you have to be very careful of re-exposure,” he warns.
Kim Campbell Thornton is an award-winning author who has written many articles and more than a dozen books about dogs and cats. She belongs to the Dog Writers Association of America and is past president of the Cat Writers Association. She shares her home in California with three Cavalier King Charles spaniels and one African ringneck parakeet.