Here is a video of a mini dachshund running in one of my fleece coats. Because this jacket was made just for him, he can move really well in it without getting all tangled up.
Many dog breeds, like dachshunds, Italian greyhounds, pugs, greyhounds, .......... the list is very long, have unique builds that are perfect for their breeds but not perfect for most ready made coats.
Dachshunds are long bodied with short legs.
Italian greyhounds are very slender but also deep chested.
Pugs are short backed but stocky.
If the coat is not long enough, it doesn't cover very much of the dog. If it is too long, it can interfere with movement.
If it goes too far down, the legs can get bound up and make moving and running difficult.
If it isn't built for a broad dog, it can also bind, or just not go on at all.
If a dog isn't comfortable in something, he or she is likely to resist wearing it or tear/chew it off. If something feels good or solves a problem (like stopping the shivering from the cold), it is much more likely to be left alone.
The point of putting a coat on a dog is to help keep him or her comfortable. Making sure the coat is a good fit will go a long ways toward that goal and keep your best friend happy!
