There is no parity between a human (rational) soul and an animal soul and so no, animals do not receive grace. This is not solely on account of the rational nature of the human soul, but on account of the fittingness of the rational soul for communion with God. The image of God in the human person is the image of reason, and it is in virtue of this image (which animals do not share) that we merit, through Christ, eternal life.
As for the “group spirit” (sometimes called “universal soul” doctrine), we have to reject this as not compatible with the Faith that has been handed down to us through the Church; in particular, what has been revealed about creation and the Incarnation. St Thomas for example explains why the universal soul doctrine is to be rejected in Disputed Questions on Spiritual Creatures and in the Summa (see for example ST III, q.35, a.2, ad.1). In a nutshell, each human soul is created by God and is unique and unrepeatable.