I am curious as to the ontological character of the dog. Hmmmm....?Before addressing the question, I must admit I have mixed feelings about dogs, cats, and other pets who live kingly lives. They are sheltered, admired, loved, and even spoiled by owners who give them the best seats and beds in the house. My husband, an ex-farmer, has an even greater problem with such animals. When he hears that an animal has been given a human name, he often cringes because he suspects the animal may be treated as a substitute human being.
Both of us see that many dogs and cats are substitute 'children' for deliberately barren 'parents' in a contraceptive society. Many people tell me about their Mikey, or Annabelle, or Ernie who solve a craving of their owners to feel loved. Eventually, the dogs and cats become as important as real people, and sometimes lead persons into isolation from other human beings. The person may prefer to live with their animals who will never criticize them. All of us know people who put animals on a par with their spouse, parents, and children. After death, these people even leave their estates to animals, rather than to relatives or poor people.
Yet I remember St. Francis of Assisi is the patron saint of animals--from the ravaging wolf of Gubbio to the small birds who listened to Francis' sermons. [Did the wolf have two angels, and was the bad one kicked out by St. Francis?] I also see many older people who must live alone, rather than in the close presence of their family. Their pets have become natural friends and are proven to help keep people mentally healthy and even to help them physically.
Now for my answer to Marc Joseph: [BTW, 'ontological' refers to the nature of being of the dog, Bella.] All animals are created by God for the benefit of man (Genesis). When Bella dies, her physical life ends. Bella has no spiritual life--it was never created. However, the design of the dog (not the being) continues to exist and could be used again by God in Heaven (Paradise)--known to be a place to accept our resurrected physical bodies.
The Bible identifies nine classes or orders of Angels: Archangels, Angels, Princedoms, Powers, Virtues, Dominations, Thrones, Seraphims, and Cherubims. According to Aquinas, the angelic order, Virtues, has power over corporeal nature in the working of miracles; they rule the physical universe and possess the bodies of animals and physical things to achieve God's will. Likewise the old Catholic Encyclopedia concludes that the practically unanimous view of the Fathers is that the angels put into execution God's law regarding the physical world.
When the ram replaced Isaac for the sacrifice of Abraham, who made the ram get caught in the bush? Who opened the spring to flow when Moses struck the rock? Who makes the wind rustle in the trees? [(2 Samuel 5:23, 24; 1 Chronicles 14:14, 15)] I suspect God uses his angels far more than we know to love us and assist us in reaching heaven. So is Bella the dog with a guardian angel a reasonable story character--I think so.