As of May 27th 2015, PetSmart announced that Himalayan Corporation of Mukilteo, Washington recalled the Himalayan Ruff Roots All-Natural Dog Chew Toys. The product was recalled due to a potential metal contamination. The contaminated products include: Ruff Root Sprout, Ruff Root Stump, and Ruff Root Stock Dog Chew Toys.
The most common toxic metals that affect canines are aluminum, lead, mercury, arsenic, and cadmium. Symptoms of metal poisoning consist of: lethargy, lack of appetite, weakness, vomiting, diarrhea, and in extreme cases it can also manifest as hysteria and anxiety.
For further information, refer to the official recall announcement.