Theosophy teaches that animals also reincarnate, but unlike humans, animals have their seven principles much less developed than humans (and mainly the three above).
And this prevents the animals from having all that post-mortem experience so complex and prolonged that humans have.
(And which I detail in the article: What happens after we die?)
And that is why, while humans, after to be in the astral plane, they ascend to the Kama-Loka and then to Devachan, and take on average 1’500 years before returning to reincarnate.
In the case of animals, they after dying remain for a short period in the astral plane and quickly reincarnate again, either in the same species in which they were born in their previous life, or in a higher animal species.
And the instructor who spoke the most on this topic was William Judge who wrote the following article, titled:
REINCARNATION OF ANIMALS
« Very little has been said on the question whether or not the theory of Reincarnation applies to animals in the same way as to man.
Doubtless, if Brahman members well acquainted with Sanskrit works on the general subject were to publish their views, we should at least have a large mass of material for thought and find many clues to the matter in the Hindu theories and allegories.
Even Hindu folk-lore would suggest much. Under all popular “superstitions” a large element of truth can be found hidden away when the vulgar notion is examined in the light of the Wisdom-Religion.
A good instance of this on the material plane is to be found in the new treatment proposed for small-pox. The old superstition was that all patients with that disease must be treated and kept in darkness. But the practice was given up by modern doctors.
Recently, however, some one had the usual “flash” and decided that perhaps the chemical rays of the sun had something to do with the matter, and began to try red glass for all windows where small-pox patients were.
Success was reported, the theory being that the disease was one where the chemical rays injured the skin and health just as they do in ordinary sunburn.
Here we see, if the new plan be found right, that an old superstition was based on a law of nature.
In the same way the folk-lore of such an ancient people as the Hindu deserves scrutiny with the object of discovering the buried truth. If they are possessed of such notions regarding the fate of animals, careful analysis might give valuable suggestion.
Looking at the question in the light of Theosophical theories, we see that a wide distinction exists between man and animals.
Man reincarnates as man because he has got to the top of the present scale of evolution. He cannot go back, for Manas is too much developed.
He has a Devachan because he is a conscious thinker. Animals cannot have Manas so much developed, and so cannot be self-conscious in the sense that man is.
Besides all this, the animal kingdom, being lower, has the impulse still to rise to higher forms. But here we have the distinct statement by the Adepts through Blavatsky that while possibly animals may rise higher in their own kingdom they cannot in this evolution rise to the human stage, as we have reached the middle or turning-point in the fourth round.
On this point Blavatsky has, in the second volume of the Secret Doctrine (first ed.) at p. 196, a foot note as follows:
« In calling the animals “Soulless,” it is not depriving the beast, from the humblest to the highest species, of a “soul,” but only of a conscious surviving Ego-soul, i.e., that principle which survives after a man and reincarnates in a like man.
The animal has an astral body that survives the physical form for a short period; but its (animal) Monad does not reincarnate in the same, but in a higher species, and has no “Devachan” of course. It has the seeds of all the human principles in itself, but they are latent. »
Here the distinction above adverted to is made. It is due to the Ego-Soul, that is, to Manas with Buddhi and Atma. Those principles being latent in the animal, and the door to the human kingdom being closed, they may rise to higher species but not to the man stage.
Of course also it is not meant that no dog or other animal ever reincarnates as dog, but that the monad has tendency to rise to a higher species, whatever that be, whenever it has passed beyond the necessity for further experience as “dog.”
Under the position the author assumes it would be natural to suppose that the astral form of the animal did not last long, as she says, and hence that astral appearances or apparitions of animals were not common.
Such is the fact. I have heard of a few, but very few, cases where a favorite animal made an apparitional appearance after death, but even the prolific field of spiritualism has not many instances of the kind. And those who have learned about the astral world know that human beings assume in that world the form of animal or other things which they in character most resemble, and that this sort of apparition is not confined to the dead but is more common among the living.
It is by such signs that clairvoyants know the very life and thought of the person before them. It was under the operation of this law that Swedenborg saw so many curious things in his time.
The objection based on the immense number of animals both alive and dead as calling for a supply of monads in that stage can be met in this way. While it is stated that no more animal monads can enter on the man-stage, it is not said nor inferred that the incoming supply of monads for the animal kingdom has stopped.
They may still be coming in from other worlds for evolution among the animals of this globe. There is nothing impossible in it, and it will supply the answer to the question,
Where do the new animal monads come from, supposing that all the present ones have exhausted the whole number of higher species possible here?
It is quite possible also that the animal monads may be carried on to other members of the earth-chain in advance of man for the purpose of necessary development, and this would lessen the number of their appearances here.
For what keeps man here so long is that the power of his thought is so great as to make a Devachan for all lasting some fifteen centuries (with exceptions) and for a number who desire "heaven" a Devachan of enormous length. The animals, however, being devoid of developed Manas, have no Devachan and must be forced onwards to the next planet in the chain.
This would be consistent and useful, as it gives them a chance for development in readiness for the time when the monads of that kingdom shall begin to rise to a new human kingdom. They will have lost nothing, but, on the contrary, will be the gainers. »
(William Brehon (William Judge), Path magazine, April, 1894)