Dog Ate a Spotted Lanternfly? Upset Stomach Signs to Watch

Dog ate a spotted lanternfly? No toxin is confirmed, but it can upset the stomach. Watch for drooling or vomiting and keep pets off sprayed trees.

If your pet may have eaten bugs from a tree or yard that was sprayed with insecticide, or chewed on milkweed, call ASPCA Animal Poison Control (888) 426-4435 or Pet Poison Helpline (855) 764-7661 now (a fee may apply). If it is trembling, having a seizure, collapsing or struggling to breathe, go to an emergency vet in person now.

Spotted lanternflies turn up on tree trunks, decks and patios in parts of New York and Virginia, and curious dogs snap them out of the air. If your dog just caught and swallowed one, here is what the sources actually say, what to do at home and when to call a veterinarian.

Dog ate a spotted lanternfly: is it poisonous?

Cornell Cooperative Extension (Ontario County) says: "There have been no confirmed toxins in spotted lanternflies to-date." That is not the same as calling them harmless, and it is not a promise about every pet.

Poison Control (the National Capital Poison Center, a poison center for people) says: "While spotted lanternflies are not known to be toxic to pets, some veterinarians have reported that curious pets who have eaten a spotted lanternfly may experience a temporary upset stomach, drooling, diarrhea and loss of appetite."

Cornell Cooperative Extension also says: "Spotted lanternflies do not bite or sting humans, pets, or wildlife." A bigger worry can be what the bug was sitting on, such as a sprayed tree or yard, or what else your pet chewed, such as milkweed.

Emergency signs first: sprays, milkweed and seizures

Before you settle in to watch at home, rule out the situations that need help right now:

Your pet may have eaten bugs from a sprayed tree or yard: call ASPCA Animal Poison Control at (888) 426-4435 or Pet Poison Helpline at (855) 764-7661. Both answer 24/7, and a fee may apply.
Your pet chewed or ate milkweed: call one of the same two pet poison lines.
Your pet is trembling, having a seizure, collapsing or struggling to breathe: go to an emergency vet in person now. If a sprayed area is possible, call a poison line on the way.

Why sprays and milkweed? Poison Control notes: "Also, insecticides are used to control spotted lanternflies. It is best to keep pets away from areas that have been sprayed with insecticides." Some people plant milkweed to fight lanternflies, and Poison Control warns people to "be sure to keep kids and pets from eating milkweed plants as they contain cardiac glycosides."

Seizures are a different story. Cornell Cooperative Extension says: "To date, there is no evidence that spotted lanternflies have caused seizures in pets or blisters on pet’s paws." So tremors or a seizure after a lanternfly snack point to another cause, and they mean an emergency vet in person now. Do not wait to see whether they pass.

If you are not sure, treat it as an emergency: go to an emergency vet in person or call a pet poison line now. This checklist of pet emergency signs is worth reading ahead of time.

What to do right away at home

If none of the emergency branches apply, a few simple steps help right after it happens:

Move your pet away from any more lanternflies, and pick up any bugs within reach.
Look in its mouth for wing pieces and note what you see; do not reach into the mouth or throat.
Offer fresh water.
Note roughly when it happened and how many your pet ate.
Take a photo of the insect, or what is left of it, so a veterinarian can confirm what it was.

Do not try to make your pet vomit, and do not give any human medicine.

Cornell Cooperative Extension's advice is: "Monitor your pet’s behavior and always consult your veterinarian for advice and treatment if necessary." Both halves matter. Watching at home is not a way to decide on your own that everything is fine, so if you are unsure, call a veterinarian.

If your dog becomes lethargic or keeps drooling, call a veterinarian now and have your notes and photo ready. If a sprayed tree, yard or milkweed is possible, call a pet poison line first.

Normal tummy upset vs. a reason to call

Cornell Cooperative Extension says: "Veterinarians have only reported upset stomachs, drooling, or loss of appetite from eating lanternflies." Poison Control's list of what veterinarians have reported in pets adds diarrhea.

The key word is "continues." Cornell Cooperative Extension says: "If your pet continues to exhibit symptoms like vomiting, loss of appetite, or drooling, this could be a sign of a larger problem or illness with your pet other than just spotted lanternfly consumption." Signs that keep going may point to another illness, which is why an exam matters.

Call a veterinarian if your pet:

keeps vomiting or retching
skips meals or stops eating
keeps drooling
has diarrhea
seems weak, lethargic or unusually quiet

You may come across Poison Control's line that the symptoms "are self-limited and do not typically require treatment." Poison Control is writing about people who swallow a lanternfly, not about pets. In the same passage about people, it adds: "It is not known if eating large amounts of spotted lanternflies or if eating them chronically can lead to more serious symptoms." That open question is a good reason not to let lanternfly hunting become a habit.

The tree-of-heaven question

You may have seen posts claiming lanternflies carry poison from the trees they feed on. Poison Control notes that tree-of-heaven is the spotted lanternfly’s preferred host, and it says: "There is a theoretical risk that spotted lanternflies may sequester toxins from whatever plants they eat."

Cornell Cooperative Extension adds that "there is not a consensus in the scientific community about toxin sequestration in lanternflies and more research is being conducted to support or refute this claim."

In plain words: it is possible, it is unproven, and it is one more reason to stop the habit.

Cats and lanternflies

Cats stalk and bat at adult lanternflies on decks, screens and patios, and the same guidance applies to them.

Cornell Cooperative Extension's advice covers cats too: "You can let your pets play with them or squish them, but avoid having them lick or ingest lanternflies for their safety and general health."

A cat that keeps vomiting, hides or stops eating should be checked by a veterinarian.

What a RexVet online vet can and cannot do after a lanternfly snack

Once the emergency branches are ruled out, a video visit can help you sort out what you are seeing. A RexVet veterinarian can:

confirm from your photo whether the insect was a spotted lanternfly
watch your dog or cat on camera
check the mouth and hydration cues you are coached to show
go over what else your pet may have reached, such as a sprayed tree, milkweed or a sticky tree band
help decide whether watching at home is reasonable or your pet should be seen at a clinic

A video visit cannot run bloodwork, give fluids or take X-rays; a pet that needs any of those has to be seen in person.

If the veterinarian decides medication is appropriate, they can prescribe where state rules allow.

RexVet is a non-profit veterinary telehealth service. RexVet's veterinarians are licensed in Florida, New York and Virginia and are available 24/7, including nights, weekends and holidays. A video visit is $64.99, and you can book a RexVet video visit from your phone. A video visit does not replace an emergency vet or a pet poison line.

Lanternfly season in New York and Virginia: why fall is peak time

Penn State Extension, writing about its own state, says adults "begin to emerge in July and remain active as adults until they are killed by hard freezes later in the fall," and that "the eggs are laid in the fall (September to December)." Local timing can differ.

In New York, Cornell Cooperative Extension (Dutchess County) points to "the widespread distribution of spotted lanternfly in NYC, Long Island, and Lower Hudson Valley Counties."

In Virginia, the Virginia Department of Agriculture and Consumer Services says: "Spotted lanternfly was originally found in Virginia in 2018 and has now been found in more than half of Virginia’s counties and independent cities."

Sticky tree bands are a hidden risk. Some people wrap trunks with sticky material to catch lanternflies, and Penn State Extension warns that "this sticky material is not selective and can capture other animals, including pollinators, butterflies, birds, squirrels, and more." A curious pet can get stuck too. If that happens, follow these steps for getting a dog or cat off a glue trap safely.

Breaking the lanternfly-snacking habit

Cornell Cooperative Extension says: "It is recommended to not have your pet eat lanternflies because it is not a part of their regular diet." If your dog keeps catching and eating them, talk with your veterinarian.

A few habits make lanternfly snacks less likely:

Leash your dog near infested trees. Cornell Cooperative Extension (Dutchess County) says "Spotted lanternflies are easiest to spot at dusk or at night as they migrate up and down the trunk of the plant," so keep your dog close near those trees at those times.
Bring food and water bowls inside, or clean them often. Poison Control notes that "insects in general are attracted to food and water bowls."
Keep pets inside while anyone sprays nearby, and keep them away from sprayed areas afterward.
Keep pets away from milkweed in your yard or a neighbor's.
Practice a "leave it" cue on walks, and reward your dog for walking past bugs.

Lanternflies are not the only fall insect that ends up in dogs' mouths. If your dog also goes after beetles, here is what to do when a dog eats ladybugs or Asian lady beetles.

When to be seen in person in Florida, New York or Virginia

Take your pet to a clinic in person if you notice:

vomiting that keeps coming back
not eating
blood in vomit or stool
a painful belly
weakness or lethargy

Any possible contact with a sprayed area or milkweed goes to a pet poison line first, even if your pet seems fine. A pet that is trembling, having a seizure, collapsing or struggling to breathe goes to an emergency vet now.

In Florida, a telehealth veterinarian must give you the contact information for at least one physical veterinary clinic in the vicinity of your pet's location.

If your pet snacked on a lanternfly and you would like a veterinarian to look things over, RexVet's veterinarians are licensed in Florida, New York and Virginia and are available 24/7. A video visit is $64.99, and pet parents in those three states can book a RexVet video visit day or night.

Frequently Asked Questions

Are spotted lanternflies poisonous to dogs?

Cornell Cooperative Extension says there have been no confirmed toxins in spotted lanternflies to date, and Poison Control says they are not known to be toxic to pets. Some veterinarians have reported a temporary upset stomach, drooling, diarrhea and loss of appetite in pets that ate one (Poison Control). That does not make them safe to eat, and whether they pick up toxins from the plants they feed on is still unproven.

My cat ate a spotted lanternfly. What should I watch for?

Watch for the signs veterinarians have reported in pets: upset stomach, drooling, diarrhea and loss of appetite (Poison Control). Cornell Cooperative Extension's advice is to monitor your pet's behavior and always consult your veterinarian for advice and treatment if necessary. A cat that keeps vomiting, hides or stops eating should be checked by a veterinarian.

Can a spotted lanternfly bite or sting my dog?

No. Cornell Cooperative Extension says spotted lanternflies do not bite or sting humans, pets, or wildlife. For pets, the concern is eating them, not being bitten.

Can eating a lanternfly cause a seizure?

Cornell Cooperative Extension says there is no evidence to date that spotted lanternflies have caused seizures in pets. A seizure points to another cause and needs an emergency vet in person now.

Is it OK if my dog just squishes them?

Cornell Cooperative Extension says you can let your pets play with them or squish them, but you should avoid having them lick or ingest lanternflies for their safety and general health. In other words, the play is fine; eating them is the habit to stop.