What Are the Symptoms a Dog Would Get if She Ate Weed Killer?

By Lisa McQuerrey

Weed killers routinely used on lawns and gardens have the potential to be toxic to your dog if ingested -- gastrointestinal upset, seizures and breathing problems are symptoms. Careful application and cleanup helps reduce the likelihood of accidental poisoning. Know the signs of weed killer poisoning, and act quickly to improve your dog’s odds of recovery.

How Herbicide Poisoning Happens

When used as directed, herbicides don’t usually pose a risk to dogs, especially when animals are kept away for at least an hour after spraying. Poisoning usually happens when weeds are oversprayed or when dogs come in contact with weed killer before it dries. Dogs can ingest weed killer if they chew on a container of the stuff. In some instances, dogs can be slowly poisoned over time due to herbicide run-off that gets integrated into a water source. Careful storage of all lawn chemicals is vital to ensuring your dog’s safety.

Symptoms of Weed Killer Poisoning

If your dog ingests toxic weed killer, she could experience symptoms including vomiting, muscle weakness, lethargy, diarrhea, convulsions and respiratory problems. She may find it hard to stand or walk. You might notice inflammation or chemical burns on her mouth, nose and tongue. Your pup can develop signs of poisoning just from coming in contact with toxic lawn chemicals through her skin or footpads. Over the long term, dogs that experience weed killer poisoning may be more susceptible to reproductive issues and some forms of cancer.

Dangerous Herbicides

Read the labels on weed killers and look for brands that are pet-safe. Avoid products that contain ingredients including arsenic trioxide, sodium arsenite, borax, sodium chlorate and ammonium sulfamate.

Some ingredients that may be nontoxic on their own can be dangerous in combination with others. According to the Merck Veterinary Manual, beware of atrazine, buturon, butiphos, chloridazon, chlorpropham, cynazine, 2,4-D and 2,4,5-T alone or in combination, dichlorprop dinoseb, dinoterb, linuron, mecoprop, monolinuron, MCPA (2-methyl-4-chlorophenoxyacetic acid), prometryn, propachlor, nitrofen, silvex, TCDD and tridiphane. Lawn fertilizer, plant food and mulch can be toxic to your dog if eaten. If you employ a commercial landscaper to work in your yard, ask about the type of chemicals used and whether they are pet-safe.

Take Action

It may take hours or days for the effects of herbicide toxicity to set in, so if you think your dog ate weed killer, seek medical attention right away. If you suspect weed killer poisoning, contact your vet or the ASPCA Poison Control Center, whose emergency phone number is 888-426-4435. You can expect to pay a fee.

Do not induce vomiting unless directed to by a veterinary professional or poison control specialist. In the future, carefully label and store all lawn and garden chemicals, including those used to eradicate insects and rodents, and follow the directions for safe application.