Thank you very much for writing to us here at TruthBook with your question.
You want to know whether animals have souls; unfortunately, animals do not have souls, nor do they gain eternal life. I say it is unfortunate only because so many of us have pets that we love so dearly, and who we want to accompany us into heaven. Alas...
The possession of a soul is a spiritual evolutionary development that clearly marks a being for eternal potential and differentiates that being from a mere animal. The soul has to do with making choices for survival and is associated with the presence of that "spark" of God within each person. It is this spark of God that The Urantia Book calls the Thought Adjuster. Animals cannot make choices for eternal survival and they do not possess this spark of God - only humans have it, and it is what sets us apart from the entire animal kingdom.
Here is a link to our topical study of Urantia Book teachings about the soul, in case you are not familiar with it.
There was an occasion in Jesus' life where he was able to explain why animal do not have souls or the potential of eternal existence. I hope it will add to your understanding of this topic:
130:2.8 That afternoon Jesus and Ganid had both enjoyed playing with a very intelligent shepherd dog, and Ganid wanted to know whether the dog had a soul, whether it had a will, and in response to his questions Jesus said: "The dog has a mind which can know material man, his master, but cannot know God, who is spirit; therefore the dog does not possess a spiritual nature and cannot enjoy a spiritual experience. The dog may have a will derived from nature and augmented by training, but such a power of mind is not a spiritual force, neither is it comparable to the human will, inasmuch as it is not reflective—it is not the result of discriminating higher and moral meanings or choosing spiritual and eternal values. It is the possession of such powers of spiritual discrimination and truth choosing that makes mortal man a moral being, a creature endowed with the attributes of spiritual responsibility and the potential of eternal survival." Jesus went on to explain that it is the absence of such mental powers in the animal which makes it forever impossible for the animal world to develop language in time or to experience anything equivalent to personality survival in eternity. As a result of this day's instruction Ganid never again entertained belief in the transmigration of the souls of men into the bodies of animals.
Thanks again for writing to us with your question. I hope that my reply has been helpful.