When attacked, Asian lady beetles release body fluids (called hemolymph) containing stinky and poisonous chemicals. “Hemolymph is corrosive, and can cause chemical burns to the mouth and/or gastrointestinal tract. It also has a strong repellent odor and foul taste,” says Dr. Elizabeth Doll, a veterinarian with WVRC Emergency and Specialty Pet Care in Waukesha, Wisconsin.

That awful taste and odor is why few dogs will attempt to eat more than a few of them, she says. Dog and beetle conflicts are so rare, that aside from anecdotal reports (like Bailey’s), a lone formal published paperexists on the subject. In this case, the patient had 16 Asian lady beetles embedded in the mucous membrane covering the hard palate, Doll says.

If a dog quickly swallows the beetles, erosion to the mouth appears to be minimal, says Dr. Nancy C. Hinkle, professor of veterinary entomology in the Department of Entomology at the University of Georgia, Athens. “Likely the dog will quickly seek water to wash away the taste—which is a good thing, because it minimizes the chance that beetles will get stuck in the esophagus.”

If the chemical burns are not treated properly, an infection could develop and potentially become serious. “Luckily for any dog with damage to their mouth, the gums and tissues of the mouth heal very quickly—usually within seven days,” says Dr. Jonathan Babyak, clinical assistant professor in the Emergency and Critical Care Department at Cummings School of Veterinary Medicine at Tufts University.

The cases that Mitchell saw, “were limited to anorexia due to painful ulcerations in the mouth,” she says. “The ulcers calmed down with manual removal of the beetles and treatment of the ulcers.” 

But Dr. Jennifer Coates, veterinary advisor with petMD, adds, “While I’ve not seen any cases myself, veterinarians have reported a few cases of dogs ingesting these beetles and subsequently developing vomiting, diarrhea, and other signs of gastroenteritis. One dog even died as a result.”