The federal Food and Drug Administration today released an update on its investigation into jerky pet treats: As of Sept. 24, the agency says, more than 3,600 pets have become ill and 580 have died after eating the snacks.

In a fact sheet, the FDA says the treats in question are sold as jerky tenders or strips, and list chicken, duck, sweet potato, dried fruit, and combinations of those foods in their ingredient lists. Extensive testing has been conducted to find the source of the illnesses and deaths, but to date, no definitive cause has been identified. It noted that treats are not an essential part of pets’ diets, and can be eliminated with no ill effect. It also listed signs of possible illness from the treats:

Decreased appetite or activity
Vomiting
Diarrhea, sometimes with blood or mucus
Increased drinking and/or urination
Severe symptoms, including pancreatitis, gastrointestinal bleeding, and kidney failure

The FDA encourages pet owners to visit their veterinarians immediately if they suspect their animals have been sickened by jerky treats. For their part, veterinarians received letters asking them to create online reports of any animals who become ill after eating the snacks, and to conduct urine and blood testing on any pets who visit with those symptoms. Doctors are asked to freeze urine samples and retain them for 60 days, as the agency may request them after receiving a report of illness.

Pet owners are asked to report illness to the FDA through its online Safety Reporting Panel (safetyreporting.hhs.gov), and to contact the food/treat manufacturer as well if a pet becomes ill. A relay service is available for those who need it: call 800-877-8339 from a TTY device.