Jakarta. The death of four tigers in at the Bukittinggi Zoo in West Sumatra has left wildlife organizations and authorities questioning the degree of care given to the animals.

West Sumatra Deputy Governor Nasrul Abit said x-ray results indicated the tigers — two Sumatran tigers and two clouded leopards — suffered birth defects leading to a complication in their lungs.

“The analysis showed that the four tigers have been sick since birth due to internal defects. There were abnormalities in the lungs, weakening the animal’s bodies to the point of no return,” Nasrul said on Tuesday (19/07), as quoted by state news agency Antara.

He urged for better management at the zoo to prevent future incidents.

“All responsible parties must pay attention to this,” he said.

The deaths were announced by Margo Utomo, regional head of the conservation of natural resources.

The two Sumatran tigers were pronounced dead on June 30 and July 1, with the female cub diagnosed with a coronary heart disease and the male cub suffering digestive tract inflammation. Haemorrhaging was found in the lungs, spleen and liver of both cubs.

“The two Sumatran tiger cubs died a day after the other, with the female cub’s condition much worse than the male’s,” Tri Nola Mayasari, Bukittingi Wildlife and Cultural Park veterinarian, said on Monday.

The four deaths have raised suspicions among animal activists that the zoo had given the endangered animals inadequate care.

As reported by environmental news portal Mongabay Indonesia, Suhandri, Sumatra regional leader of World Wildlife Fund Indonesia, called for further investigation into the deaths.

Suhandri suspects the deaths are due to natural causes, but involved human error and questions if the tigers were given a decent home and professional care.

If further investigations find unfair treatment, Suhandri said legal action should be taken against the zoo.

WWF Indonesia has also lent a hand to the government to stop incidents like this to occur in the future.

“We have a dedicated team of tiger specialists and we are ready to help if needed,” he added.

Based on WWF Indonesia’s survey, Bukittinggi Zoo is one wildlife park in serious need of a revamp.

“The level of professionalism of Bukittinggi Zoo is not enough and it’s time to move them [the animals] to a better place. The problem is, where do you move them to?” Suhandri said on Saturday (16/07).

Sumatran tigers have recently been moved onto the International Union for Conservation of Nature — an organization dealing with environmental conservation — "red list" of the world's endangered species, with less than 400 tigers left in the wild.

Zoos in Indonesia have been famously criticised for improper care of animals. In May, a Sumatran elephant died due to neglect in Bandung zoo and further investigations found the animals were living in below par standards.

Meanwhile in Surabaya, the ‘Zoo of Death’ has seen far too many lives lost in 2014, including komodo dragons, orangutans, deers, tigers and many more.