The orphaned cub was discovered at Lybster, Caithness. After being checked by vets in Thurso, it was taken to the Scottish Society For Prevention Of Cruelty To Animals' rescue centre in Fishcross, Clackmannanshire.
She was initially cared for by SSPCA's senior inspector Audrey Gunn, who named her Murkle after the Caithness village where she had grown up herself.
She said: "Murkle was very sick, weak and lethargic when found. Sadly, it's possible her mother has been killed or frightened off. She would not have been able to survive on her own as otters usually stay with their parents until they are around a year old.
"After some time in a heated room at the vet Murkle became a lot brighter."
Staff will soon adopt a "hands-off approach" to allow Murkle to develop a natural fear of humans. Ms Gunn said: "This is vital if she is to survive in the wild."
It is hoped Murkle will be released this time next year.