Brockswood Animal Sanctuary in Sedgley has posted a message across its social media channels about Fiona, a raccoon living at the sanctuary.
The sanctuary said Fiona, who is one of the most popular animals for sponsorships, had been poorly over the last few weeks and was back in hospital after being discharged last week.
A spokesman for Brockswood Animal Sanctuary said: "We've had a hard couple of weeks caring for our little Fiona, who we’re sad to say is quite poorly.
"We're fighting hard to get her better and have some of the best vets and nurses working with her, but today she has been hospitalised again after being discharged last week.
"We're so worried, but she's in the very best place right now with everything she needs and round-the-clock care and treatment.
"Not having her here with us is heartbreaking, but we need to give her every possible chance right now.
"Fingers and paws crossed for our dear Fiona.
"To stand in the vet surgery and not have to think twice if we can give her the treatments she needs; the many tests, overnight stays, because of the cost (we all know how fast a vet bill can mount up), thanks to your donations, is something we can’t thank you enough for."
To find out more about Fiona and to make a donation, go to brockswood.org.uk/product-page/sponsor-the-raccoons.