The zoo’s head vet said that Tian Tian was still showing signs that her body was preparing for birth, including producing colostrum - an early form of milk - for her potential cub, but admitted that there was a possibility it could be a “pseudo pregnancy”.
Meanwhile, zoo officials said her mate, Yang Guang, had been diagnosed with a “minor metabolic disorder” and had been off colour for a few weeks.
“We know it seems hard to believe after all this time, but Tian Tian, our female giant panda, is still continuing to show signs of being in the late term of pregnancy,” said Simon Girling, Head of Veterinary Services for the Royal Zoological Society of Scotland.
“Her behaviour has mellowed out over the past few days, which is a very positive sign and she has also started to produce colostrum.
“As pandas experiencing a pseudo-pregnancy also produce colostrum and behave just as a pregnant panda would, these signs are still not 100 per cent indicative of pregnancy, but while Tian Tian continues to show signs of late term pregnancy, we will continue to treat her in that way, which means allowing her to enjoy time off show while keepers monitor her around the clock.”
On 10 September the zoo said that Tian Tian may have experienced a spike in a hormone called progesterone two weeks later than the results suggested, leaving the window for a possible birth open until next week.
Edinburgh’s female panda was artificially inseminated with the sperm of Yang Guang and another panda, Bao Bao, from Berlin Zoo, in April. In early August the zoo first indicated that she could be pregnant.
Mr Girling said zoo medical experts had carried out blood tests on Yang Guang after he appeared unwell.
“Yang Guang, our male giant panda, has been off colour for a few weeks,” he said. “We believe he may have a minor metabolic disorder with reduced blood levels of calcium and since starting a regime of supplements he has shown significant improvement and his keepers are really happy with him. We expect him to recover in a matter of weeks.”