There is no one-stop answer to why dogs walk backwards, but it does help to have some theories in mind.
Usually, when dogs walk backwards they are trying to gain more traction on the ground. This is especially helpful when they are on slippery or icy surfaces.
Some dogs will also go backwards when they are scared of something. These can be loud noises, sudden movements, and so on.
A fearful dog will shiver, shake, and cower while walking backwards. They may also whimper, pant, and pace to try and hide from the source of their anxiety.
This type of behavior can be a sign that your dog is suffering from an injury or pain. They might have injured their hindquarters and the backward movement is a way for them to move without having to worry about putting pressure on the point where they are hurting.
These injuries can be severe and could need to be treated by a veterinarian.
Another theory about why dogs walk backwards is that they are trying to show dominance over people or other animals in the room. Dominant dogs need to prove their status so they can get the food or territory that they want.
This is a very rare occurrence and it doesn’t always lead to behavioral problems, but if you notice that your dog is walking backwards frequently, then it might be time to consult with a vet. The vet will be able to give you some advice on how to solve this problem.