Two black bears and an injured mountain lion cub were taken last month to the Wildlife Investigations Laboratory, Sacramento.
The animals had been so badly burnt in a forest fire that the bears could not stand.
Veterinarians estimated that their burns would take up to six months to heal.
The dilemma facing the vets was that if the animals were kept at the laboratory, there was a danger that the bears would become institutionalised. No one wanted this.
Deana Clifford, a senior vet at the laboratory, consulted Jamie Peyton, a vet who is associate director of the UC Davis Centre for Advancing Pain Relief. He recalled an experimental treatment of human burn victims in Brazil, using skins of tilapia, a freshwater fish, as bandages. The skins are high in collagen, which was said to help the healing process.
During treatment, the fish skins were promptly stitched on to the animals' feet.
Said Dr Peyton,
“One of the first things that the bear did was stand up after we applied them.”
The animals have now stepped back into the Californian wild.