ANOTHER DANGER OF SPOT ON FLEA-TICK TREATMENT

Dog owners are becoming more and more concerned about flea and tick treatments, both spot on and feed through. Read on. . .

Dog stuck in crate highlights rare risk of spot-on flea treatment
October 7, 2009

By: Edie Lau For The VIN News Service

A veterinarian presented with a peculiar case of a poodle stuck in its crate last week traced the problem to the pet’s spot-on flea treatment. Residue from the product Advantage, which was applied between the poodle’s shoulders, somehow came in contact with the plastic base of the animal’s crate, dissolving the plastic and causing it to adhere to the dog’s belly. When the dog wouldn’t come out of its crate the next morning, its concerned owner brought the dog, crate and all, to Dr. Tej Dhaliwal of North Town Veterinary Hospital in Ontario, Canada. Following two hours of sleuthing, Dhaliwal concluded that benzyl alcohol, an inactive ingredient in Advantage, was to blame.

Animal Health, maker of Advantage, acknowledged that the flea treatment was the likely culprit and offered to pay the owner’s veterinary bill, compensate him for loss of salary and replace the crate, Dhaliwal said.

Bob Walker, a spokesman for Bayer in the United States, confirmed that Advantage contains benzyl alcohol, which reacts with certain plastics. He said he consulted with colleagues in veterinary services and was told, “We know it can happen, but we’ve never seen it.” Walker said a lead veterinarian in the department thought that most of the veterinary community was aware of the potential for the product to react with plastic. Walker said that he personally had not heard of such a thing before. He added, “My counsel would be, if you’re not aware, you need to be aware.”

The incident certainly surprised Dhaliwal, a practitioner for 13 years, who posted his experience in an online discussion board of the Veterinary Information Network (VIN). Some veterinarians said they were familiar with the potential for the product to damage plastic, but many were astonished by the news.

Dhaliwal said the owner of the dog, a 15-year-old poodle mix, had applied Advantage to the dog before bedtime. He speculated that the dog rolled over in the crate before the liquid pesticide dried. Presumably, residue of the product made contact with the plastic floor of the crate, causing the plastic to dissolve and “glue” the dog in place overnight.

Dhaliwal noted that the dog had been unable to eat, drink or relieve itself for 15 hours by the time he managed to free it with a tool normally used to scrape excess plaster from drywall. The white dog had a patch of dark gray plastic about 6 inches by 4 inches stuck to its fur. Following the advice of representatives at Bayer, Dhaliwal said, he removed the remaining plastic using the contents of another two tubes of Advantage. Once freed, the dog was fine.From the start, the dog’s owner suspected that the Advantage was to blame, Dhaliwal said. The veterinarian figured some chemical was involved but wasn’t sure what. At first, he applied regular alcohol to the plastic base, to no effect. Then he tried a tube of Advantage. The plastic liquified almost instantly, and his gloved hand stuck to the plastic.

Photographs snapped with his iPhone show a puddle of liquid across the bottom of the crate. Dhaliwal said one tube containing .5 cc of product covered half the crate base; he speculated that the plastic, as it dissolved, perpetuated the chemical reaction.

According to a Material Data Safety Sheet for benzyl alcohol posted at http://www.sciencelab.com/, the compound “can extract and dissolve polystyrene plastic and may attack other plastics.” The chemical is in wide use, found in hundreds of cosmetic formulations including baby toiletries, mascaras, hair dyes and skin care products, according to the article “Benzyl Alcohol Allergy: Importance of Patch Testing Personal Products,” published Feb. 15, 2006, in the journal Dermatitis. Its function in topical preparations is as a preservative, solvent, anesthetic and/or to decrease viscosity, the article states.

Walker at Bayer said the company veterinarian he consulted speculated that benzyl alcohol is found in a variety of spot-on flea treatments besides Advantage. However, it’s not possible to determine which products contain the compound by reading their labels, as manufacturers are not required to list inactive ingredients.

Dale Kemery, a spokesman for the U.S. Environmental Protection Agency (EPA), which regulates pesticides including spot-on pet parasiticides, said the agency is considering a new rule to require that manufacturers disclose pesticides’ inert ingredients. “This increased transparency will assist consumers and users of pesticides in making informed decisions and will better protect public health and the environment,” Kemery said by e-mail. “The Agency anticipates publishing an Advance Notice of Proposed Rulemaking in the Federal Register within the next few months.”

Kemery also encouraged anyone aware of adverse reactions with an EPA-registered product to report the matter to the manufacturer and directly to EPA. “Manufacturers of pesticide products are required to report to EPA information they receive about potential adverse effects of their products, but reporting to the EPA directly is beneficial because the data we receive from the manufacturers is aggregated by severity category, and the report of an individual incident that we receive directly may provide more details initially that could lead to a follow-up by EPA with the manufacturer,” Kemery said.

Walker said Bayer officials in Canada examined the lot of Advantage used on the dog to check whether it contained an abnormally high concentration of benzyl alcohol but found nothing unusual. Dhaliwal complimented Bayer for taking responsibility right away. “Obviously, this is something of ongoing concern," he added. He said he plans to write a report on the incident and submit it to a professional journal in hopes of spreading the word. “This is something that everyone needs to know,” he said.