The FDA reached out to veterinarians and pet owners today for help in figuring out why nearly 600 dogs have died and another 3,600 have gotten sick since 2007 after eating jerky treats, reports NBC News. Most of the treats have come from China, but the agency hasn't been able to zero in on exactly what's so harmful to the animals. The agency wants vets and owners to contact the FDA when affected, and vets in particular are being asked to send along blood and urine samples and be more vigilant about reporting cases, reports the LA Times.
"This is one of the most elusive and mysterious outbreaks we've encountered," says an FDA statement. (You can read the separate letter to vets here and see an FDA fact sheet on jerky treats here.) Extensive testing hasn't turned up much so far, prompting one veterinary clinical pathologist to say, "I think that what it tells us is that the intoxicant is something that we're not used to dealing with as a toxin in North America." (Read more pets stories.)