Migraine gel masks can cause potentially life-threatening toxicity in dogs, experts warn

According to case data from the Pet Poison Helpline, dogs that ingest the hydrogel inside these masks can develop severe gastrointestinal illness followed by rapid-onset neurologic signs that may be life-threatening. 

The article reports that one tablespoon of hydrogel consumed by a roughly 10lb canine “resulted in severe signs including vomiting, tachycardia, ataxia, generalized tremors, and grand-mal seizures.”  

The long-term condition of this dog is unknown due to lack of a follow-up, but other dogs that recovered from this have also shown lingering neurologic impairment at discharge, suggesting possible lasting injury in some patients. 

These masks are typically used for hot or cold therapy in migraine treatment and are often stored in freezers, refrigerators, or bedside drawers.  

The ingredients in the mask may cover the true hazard 

In reviewing the product safety sheets, the typical ingredient list for the masks is water, glycerol, and polyacrylamide. According to the paper, each of these substances alone has a relatively wide margin of safety, which can make the severity of clinical signs difficult to explain at first glance. 

The authors point out that glycerol can cause gastrointestinal irritation and osmotic effects at very high doses, but the dogs that have consumed these masks have not shown the electrolyte issues one would typically associate with that. Polyacrylamide, the polymer that forms the gel, is also considered to be minimally toxic to dogs. 

Since those ingredients do not typically cause the clinical signs reported, the attention has instead turned to acrylamide monomer. Acrylamide monomer is a toxic impurity that can remain after manufacturing or be released if the gel breaks down. Even trace amounts may be clinically important because acrylamide is a potent neurotoxin. Heating or physical degradation of the product may increase the amount of free monomer available. 

Laboratory testing of gel samples from commercially available masks has confirmed the presence of acrylamide monomer, and studies cited in the article have shown that “polyacrylamide gels may contain residual acrylamide monomer ranging from 0.01% to 0.1%.” 

Clinical response and prevention 

According to the authors of the paper, given how quickly and dangerous the poisoning is, “immediate decontamination in the asymptomatic patient followed by aggressive symptomatic and supportive care are indicated upon presentation to a veterinary facility.” 

Hydrogel ingestion should be included on the differential list for dogs presenting with acute gastrointestinal signs followed by unexplained neurologic abnormalities. 

Pet owners should store gel masks securely, discard any damaged products, and keep them out of reach during heating or cooling.