The second giraffe in a week to die at the Greater Vancouver Zoo was expecting a calf, but the facility says the death was not related to the pregnancy.

Eleah, a 23-year-old giraffe, was found dead by zoo staff on Saturday around 7:30 a.m. in her heated barn. Her nearly four-year-old calf, Amryn, died just five days earlier.

Zoo veterinarian Bruce Burton says Eleah was not in labour when she died, and the cause of death remains a mystery.

"Any animal can have problems delivering, but the calf was in a normal position, and it was still in the uterus, hadn't gotten up into the pelvis, the cervix was closed, so it was not a birth-related issue," he told CTV News.

The zoo has not determined what killed Amryn, either.

"When we found him, he was on his chest and unable to stand, and the biggest pathology that we found is that he had some muscles that were torn in the back legs. So, whether that's why he went down or whether he struggled and tried to get up, we don't know," he said.

Burton says that giraffes can be sensitive to the cold winter weather in B.C., even if they are born locally.

"Giraffes raised in northern climates are very sensitive to being underfed, and they do need to have a special diet," he said.

Both animals have been sent away to undergo necropsies, and the zoo's only remaining giraffe, Jafari, is being watched closely.

The BC SPCA says it may launch an investigation into the deaths after lab results come back in a few weeks' time.

"Clearly, if these animals have been neglected or abused, then the SPCA would certainly look at presenting charges to Crown counsel," senior investigator Eileen Drever said.

With a report from CTV British Columbia's Julia Foy