Dangerous Measures: A Case Report and Review of Motoro Ray Envenomation

Aquatic envenomations may cause severe tissue injury, neurologic morbidity, and even mortality among those whose leisure and/or occupational activities expose them to marine and freshwater animals. The Motoro ray, or Potamotrygon motoro (also known as an ocellate river stingray) is endemic to freshwater tributaries throughout Brazil, and is a frequent source of severe envenoming of local fisherman and those residing near waterways. Local wound management including immersion in warm water, wound cleaning and debridement, as well as antibiotics are mainstays of treatment, as are local anesthetics (e.g., nerve blocks) and systemic opioid analgesics; however, high-quality evidence supporting such interventions is lacking. We present a case of a Canadian who was envenomed by his pet Motoro ray, and describe his clinical presentation and evolution of symptoms over the subsequent months. With the ever-increasing trade of exotic wildlife, clinicians, public health authorities, and those within the broader wildlife regulatory ecosystem should be attuned for unanticipated adverse consequences, such as those described herein. We further situate this case within the existing published literature around this particular species of ray, which is not typically considered an ornamental fish.