You think of your dog as the third member of your family, and the two of you have an especially close bond. You let the dog sleep in your bed every night, and he always sleeps on your side. You take the dog for two walks every day, you give him food and water, and you have plenty of memories of playing fetch at the park and lounging together on the hammock.
Your spouse, on the other hand, merely tolerates your dog. The two do not have much of a bond at all. If the dog gets to choose who to go by, it is you every time.
When you and your spouse file for divorce, you think it is clear that what is best for the dog is to stay with you.
However, you should be warned that judges do not always look at it this way. The trouble is that you are thinking of the dog like a child. The judge is thinking of the dog as yet another piece of property. It's no different than a television or a car.
Therefore, judges are more interested in legal ownership. Maybe your spouse actually bought the dog with his or her own money right before the marriage. Your spouse paid all of the fees and covered all of the costs. Your spouse pays the vet bills and, though you feed the dog, your spouse buys that food.
This can lead to a very tough, emotional situation when two people cannot agree. Make sure you are well aware of all of the legal options you have.
Source: Rover, "What to Do with Your Dog in a Divorce," Elisabeth Geier, accessed June 01, 2018