The spirit takes birth in a body on the basis of its desires and karmic balance, once manifested in the birth of a human or an animal it has to go through the entire process of living experiencing and dying, all pains and pleasures have to be gone through on its own, there is no escape.

An animal manifestation ensures a natural and automatic progression into the next birth. If the animal happens to be in a genuine ashram with a yog guru and hears and feels the Vedic chants, then it will manifest as a developed human being with a strong chance for salvation, even direct salvation is possible if it has been touched by the guru.

A human being who is tied to the bondages of maya and is ruled by his desires has a tougher chance....because he thinks and judges, not that thinking is not allowed, but the problem starts when he has been blessed by a yog guru and also had has his experiences of the subtler worlds but because of his thinking [negative] brain, he starts to find faults in his guru and gets stuck to what he thinks is incorrect...he takes the role of his guru’s guru. The problem thus begins, then onwards it is a downward spiral which takes him to the lower dimensions and he gets stuck.