A tiger in its enclosure at Patna zoo. Telegraph picture

The death of a Royal Bengal Tiger cub at Patna zoo has added to the list of feline demises at the facility and cast a shadow over the claim of increased breeding.

The cub — one of the three born to tigress Swarna on the night of August 2 — died on Tuesday night. A zoo source said convulsion was the cause of death according to the preliminary post-mortem report.

Only 10 days ago, one of the two lion cubs born on August 15 had died after it was born weak. Sources said its sibling was stable.

The surviving two cubs of Swarna — a Royal Bengal tigress brought from Hyderabad zoo in August 2011 in an animal exchange programme — are also stable. The last time tiger cubs had been born in Sanjay Gandhi Biological Park was 19 years ago.

“We are taking extra care and providing a mineral-rich diet to the cubs,” said the source.

He added: “According to the preliminary findings during the post-mortem, convulsion seems to be the primary symptom for the disease, which led to its death. Convulsion could have been cased due to deficiency of minerals like potassium, calcium or iron. We conducted a CT scan of as well as ultrasound of the cub’s body.”

A veterinary doctor from the Wildlife Trust of India is supervising the treatment of the surviving feline cubs. The zoo authorities are also communicating with the Central Zoo Authority and the zoos at Hyderabad and Junagadh in Gujarat. Experts claimed that zoo authorities should now be extra-vigilant towards the well being of the cubs.

“Death of felines in captivity can be because of several reasons including lack of nutrients in their diet, post-birth infection or tendency of cannibalism in mother cats. However, causality to the newborns because of any of these factors can be prevented with prompt action. I have heard that the activities of these cubs were monitored through CCTV cameras. But still such fatal incidents occurred. So, the zoo authorities should be more careful now,” said Samir Kumar Sinha, an expert working with the Wildlife Trust of India.

Many animals at the zoo are expecting said sources. A hippopotamus could deliver within a month, four rhinoceroses and a giraffe among several others could give birth early next year.

Earlier, a newborn male giraffe calf born to seven-year-old Shrishthi died in the first week of June this year.