'Sweetie' the Siberian tiger euthanized at Vancouver Zoo

The eldest tiger at the Greater Vancouver Zoo has been humanely euthanized after suffering breathing problems, a loss of appetite and ongoing lethargy.

'Sweetie', an 18-year-old Siberiantiger, had already been through a month of veterinary treatment, includingmedication and appetite stimulants, but her condition continued to decline.

According to a press release, Sweetiewas born at the zoo and as such, outlived themedian life expectancy for tigers born in captivityof 14 years.

In the wild, there areestimated to be as few as 400 500 Siberian Tigers living primarily in eastern Russia, althoughsome exist in China and North Korea.

Tigers conservation statusis listed as vulnerable by the International Union of Conservation of NatureRed List.

A fullnecropsy, to determine exactly what cause Sweetie'sdecline, will be performed later today.