Symbolism, Imagery, Allegory
This novel is full of animals. From Barrabás's arrival at the del Valle home to the birds that Clara keeps in the enchanted portion of her house, animals seem to crop up all over the place. Oddly enough, a lot of them are in cages, out of cages, being released from cages, or put into cages. Take, for example, Barrabás the caged puppy, the animals at the zoo that give Alba a lifelong fear of imprisonment, the image of Clara releasing her caged birds, or the mean mastiffs that are tied to chains their whole lives so they'll serve as scary guard dogs at Tres Marías. It seems animals might have something to do with the theme of "Freedom and Confinement."
Additionally, it's interesting that three generations of del Valle and Trueba women embroider, mold, and paint exotic, imaginary creatures. In this way, animals serve as a link between generations and reveal a feminine connection to the imaginative and the supernatural.