Surabaya Zoo performed on the animals found plastic and wood inside the animals. The death of Melani the tiger, one of only a few hundred Sumatran tigers left in the world, outraged animal activists when it was discovered that the tiger was suffering from extreme digestive disorders before being rescued from the zoo. On 28 January 2014 Surabaya Zoo authority announced that the zoo has a collection of 3,459 animals from 197 species, but 81 animals are sick, disabled, and old, and 44 of which are in severe conditions. An online petition that calls for the closure of Surabaya Zoo due to
Hip replacement heat-treated alloys and a lack of special surgical experience accounting for most of the failures. In 2010, surgeons at medical centers such as the Mayo Clinic reported reducing their use of metal-on-metal implants by 80 percent over the previous year in favor of those made from other materials, like combinations of metal and plastic. The cause of these failures remain controversial, and may include both design factors, technique factors, and factors related to patient immune responses (allergy type reactions). In the United Kingdom the Medicines and Healthcare Products Regulatory Agency commenced an annual monitoring regime for metal-on-metal hip replacement patients