MIDDLE TOWNSHIP, N.J. — Officials at a New Jersey zoo say a snow leopard cub born earlier this year has died from an infection.

Zara, one of two female snow leopard cubs born at the Cape May County Park and Zoo in May, died Monday from an apparent infection. According to zoo veterinarians, Zara became sick on Sept. 29 and her condition worsened throughout the weekend.

Veterinarians say Zara had a severe brain infection and are still working to identify what caused the infection.

Zara’s sister Ahana and mother Tysa are being monitored for signs of illness.

The World Wildlife Fund says snow leopards are a “vulnerable” species, with an estimated population of 4,000 to 6,500 worldwide.