How to Poison Proof Your Yard and Garden

Renee DiPietro, CVT
Veterinary Information Specialist and
Ahna Brutlag, DVM, MS, DABT, DABVT
Director, Veterinary Services & Senior Veterinary Toxicologist 

Download our Spot the Pet Poisons in Your Home infographic here.

Just like us, our pets love to spend time outside in the yard and garden. The outdoor environment that we create for ourselves can bring enjoyment and joy to our lives and to our pets. In the yard and garden there can be inherent hazards and toxins that can be dangerous for our pets. Knowing what that risks are and how to keep your pets safe around these materials can go along way towards preventing toxic exposures.

Plants: There any many plants that are toxic to pets. Some cause only stomach upset when ingested but others can cause life threatening toxicities. Some of the most common plants we worry about in the yard or garden include: lilies (Lilium species); day lilies (Hemerocallis species.); lily of the valley (Convallaria majalis);  foxglove (Digitalis species); oleander (Nerium oleander); rhododendrons; azaleas; sago palms (Cycas revolute); mountain laurel (Kalmia species); certain bulbs such as tulips, daffodil, crocus, and hyacinths; grapes; Yesterday, Today, and Tomorrow (Brunfelsia species); yew (Taxus species); and castor beans (Ricinus communis). If you are planting your yard it is important to research the plants that you plan to landscape with if your pets will be exposed to your plantings. If you have moved or are planning to move to a new home, you can explore your yard to determine whether the plantings that are already there are safe for your dog or cat. Your local nursery or florist can be an important ally for plant identification. This will allow you to remove or build a barrier around any plants that are unsafe for your pets before allowing them access to your new yard. You can view our list of toxic plants and a list of safer considerations.

Fertilizers: Fertilizers come in many formulations and some of them can be toxic or contain ingredients that can be harmful in other ways. One of the toxins that we are most concerned with in fertilizers is iron. Iron poisoning can cause gastrointestinal, cardiac, metabolic and other signs of toxicity. Some fertilizers are mixed with herbicides which is another risk factor.

Many people use organic or natural fertilizers. These products can also contain hazards for pets and it is best not to assume that they are harmless. Pets are often attracted to organic/natural fertilizers because of ingredients such as bone meal or blood meal. If small amounts are ingested, the pet may only experience more minor signs; however, when ingested in large amounts, materials like bone meal can mass together and form a concretion in the stomach known as a bezoar. This is basically a rock made of bone that can pose a risk for foreign body obstruction in the GI tract. Large ingestions of these types of products may also result in pancreatitis—a potentially fatal disease caused by inflammation of the pancreas.

Pets are not only exposed to fertilizers in the yard or garden but will often access bags of these products in sheds or garages. Remember to keep the fertilizer out of your dogs reach during storage.

Pesticides: Lawn and garden pesticides are typically targeted toward insect pests. These can contain many different active ingredients. Some pesticide products are relatively harmless to mammals and expected to cause only GI irritation if ingested. Others, especially those containing organophosphates, carbamates, some pyrethroids, or other ingredients pose more significant risks for toxicity including neurologic, gastrointestinal, cardiovascular, ophthalmic and other symptoms. Pets can be exposed to pesticides in their packages (e.g., chewing into the container) or after application. These products include not only sprays or granules but products like slug killers and fly bait.

When using any type of pesticide in your yard or garden it is very important to follow instructions regarding application and re-entry so you know when it is okay for your pets to be allowed back into the area of application. Remember to store your pesticide products where your pets cannot access them.

Herbicides: Herbicides are targeted to kill plants as opposed to insects or other animal pests. In fact, some contemporary herbicides are designed to interact with enzymes only found in plants.  This means that, typically, herbicides have a wider margin of safety for pets and people compared to other pesticides. That said, dangerous products still exist (e.g. paraquat) but many are banned or restricted in the US and Canada. Ingestion of herbicides by animals can often lead to irritation of the gastrointestinal tract. In some cases, this can pose a serious situation for your pet. As with other yard products, apply as labeled, and keep you pets away from the area of application for the time labeled on the product. Store products in a safe place that cannot be accessed by pets.

Compost: Many pet owners are surprised to learn that that compost can pose multiple hazards to pets. Compost often contains moldy food or provides an excellent environment for mold growth. Some of the molds that grow on food or in compost produce toxic agents called mycotoxins. For example, Penicillium, a common mold that grows on human foods, can product tremorgenic mycotoxins—that is, toxins that, when ingested, cause severe tremors. The most common tremorgenic mycotoxin is called Penitrem A. Just a few bites of moldy food containg this mycotoxin can result in severe hypersalivation, vomiting, muscle tremors, incoordination, and seizures within minutes to hours after ingestion.

Even without the mold in compost, some inherent food contents can be toxic to your pets if ingested. Items like grapes, coffee grounds, chocolate, certain nuts and other ingredients all have toxic potential for pets. Another concern is the risk for foreign body obstruction posed by items such as corn cobs and fruit pits.

Composting is a great habit but take care to find a way to keep your pets out of the compost pile with adequate fencing or some other barrier.

Mushrooms: Mushrooms grow everywhere and become more abundant in wet seasons. They seem to spring out of no where in patches in your yard. Depending on the type of mushroom gastrointestinal, hallucinogenic, liver, central nervous system (such as seizures) and other symptoms are possible. Small amounts can cause poisoning and any mushroom exposure (other than culinary kitchen mushrooms) is considered potentially toxic.

You can reduce your pet’s exposure risk to mushrooms by not allowing your pet to roam free unmonitored and/or by checking your yard every morning for mushrooms before letting your pets out. You can remove mushrooms from the yard by pulling them (wear gloves!) and discarding them where your pets cannot access them.

Rodenticides: Many people use pesticides to control rodents around their homes and yards. The three most common types of rodenticides—anticoagulants, bromethalin, or vitamin D3—can cause internal bleeding, neurotoxicity, or kidney failure. Other, less common types such as strychnine or zinc phosphide, can although pose a risk for significant toxicity. Using a protective bait station may help reduce pet exposures although large dogs may be able to break into “pet resistant” bait stations. Keep your pets safe by ensuring that you place the product (blocks, pellets, worms, etc.) where your pets cannot access it. Store your rodenticides in a secure, pet proof location—we get as many calls about pets ingesting rodenticide from a storage site in the home as we do about pets getting into rodenticides after they’ve been placed out for rodents. Rodenticides can also pose a risk to wildlife when left where birds and other animals can access them.

Poisonous animals:  Depending on where you live, poisonous animals such as pickerel frogs, select toads, newts, caterpillars, and other animals, may inhabit your yard and garden. Examples of such creatures include the Rough-Skin Newt (Taricha granulosa) in the Pacific northwest. The skin of this salamander-like animal contains a cardio toxin called tetrodotoxin. Ingestion of this newt may lead to cardiopulmonary arrest and death in pets. Rough-skin newts are native to northern California, Oregon, Washington, and extreme southern Alaska. Other examples of poisonous animals in the US are the Colorado river toad (Incilius alvarius), native to the southwestern region of New Mexico, and southern regions of Arizona and California, and the Marine (Cane) toad (Rhinella marinus), an introduced (non-native) species living in Florida, Texas, and Hawaii. These toads, formerly referred to as “bufo toads”, have two large parotid glands on each side of the head that can release toxins when a toad is mouthed/chewed on or ingested. Poisoning has even occurred when dogs drink from a water dish that the toad has been sitting in. These toxins can rapidly cause respiratory, cardiovascular, neurological (seizures, paralysis) signs, and death in pets.

If you ever catch your pet with a toad or newt that you suspect could be toxic rinse out there mouths well with tepid water and call your veterinarian or an animal poison control center immediately.

Venomous animals: Venomous animals cause harm by injecting their toxic venom via a bite or sting (vs poisonous animals which cause harm after their poison has been ingested, inhaled, or touched). Venomous animals such as snakes, spiders, bees, wasps, scorpions and others live in most yards and gardens. Examples of animals with wide geographic distributions in the US include two families of insects in the order Hymenoptera—wasps, hornets, and yellow jackets (Vespoidea species)—and bees (Apoidea species). Black widow spiders (Latrodectus species) are found in every US state except Alaska. Brown recluse spiders (Loxosceles species) are found primarily in the southern Midwest with some species located in southern western states. It is a common misconception that brown recluse spiders are widespread across the US.

Venomous snakes are found in most US states although the species depends heavily on the geographic area. Common examples of snakes include cotton mouths/water moccasins and copperheads in the south and south eastern US. Timber rattlesnakes (Crotalus horridus) are found in small to large pockets throughout most of the eastern half of the US from Minnesota to Florida. The prairie rattlesnake (Crotalus viridis ssp.) are also found in pockets from Texas to Arizona and north into Canada. Unsurprisingly, the southwest US is a hotbed for venomous species including many snakes and scorpions.

Most venomous animals are reclusive, not aggressive, but will protect themselves with their venom when they feel threatened. Depending on the type of venom and the area of the bite, the potential for toxicity can range from mild to severe. Bites and stings are not always witnessed but behavior such as sudden vocalization, pawing at the face, limping, or the presence of redness, swelling, hives, or puncture wounds on your pet may indicate they have encountered a venomous animal. While some of these encounters may have mild and transient affects, others can be more serious and encounters such as these are best avoided.

If you are aware of a hive or other abode of a venomous animal on your property, it is best to have the venomous creature or creatures removed by a professional or restrict access to the part of your yard where your pet is at risk of encountering a venomous animal or insects.

Mulch: Some mulch can cause poisoning when ingested. Other risks include GI irritation and foreign body obstructions. Cocoa mulch is especially concerning as it can contain high levels of theobromine and caffeine (the components of chocolate that are toxic to dogs). Dogs seem to be attracted to this mulch and have been known to ingest it with life-threatening consequences. This is a product you may want to try and find an alternative for or at least use in a place where your dog will never have access.

When planning your yard or garden, a little diligent research and consultation with your veterinarian or an animal poison control service can go along way in protecting your pet from hazards. The knowledge that your outdoor haven is safe for your pets will increase the enjoyment of spending time there.

Even with the best planning and intentions our pets will occasionally be exposed to toxic substances in the yard or garden. If you suspect your pet has had a toxic exposure call your veterinarian or Pet Poison Helpline immediately as time is of the essence. It is not always safe to induce vomiting or administer other home remedies. Seek counsel before taking action.