Here’s a new one for me: Some topical flea medications contain an alcohol that can melt plastic. For one dog, that resulted in a very surprising problem: He got stuck to his crate. 

When Dr. Tej Dhaliwal of North Town Veterinary Hospital in Ontario, Canada was first presented with the distressed poodle, its belly was stuck to the bottom of its crate. The poodle's owners had brought it in to the hospital, crate attached. How exactly this reaction had happened was a mystery to Dr. Dhaliwal, but after thoroughly questioning the owners, it became apparent that it had resulted from the misapplication of a topical flea product the owners had used on their dog's underside.

Bayer, the manufacturer of Advantage for dogs (the brand used in this case), copped to it right away. According to a recent Veterinary Information News Service article:

"Bayer 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 ...

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' ...

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."

So it’s safe to say that any flea and tick topical could potentially cause the same sticky reaction. Please use caution, and read the instructions.  

Dr. Patty Khuly