For some short coated breeds people like to use coats and jumpers to keep them warm and dry, especially in colder climates where they still need to go outside to be walked etc.
You can't just put a top on a dog and expect him to be happy wearing it. Like with anything It helps if you start training at an early age when the pup is a youngster, this will give them time to adapt and learn about what you want from them and they will get used to wearing a coat and usually associate it with going out for a walk
For the first week
- Practice putting the top on your dog each day just for a few seconds or minutes (whatever they are happiest with) you can reward good behaviour with praise or a small treat
- Put the top on your dog for 20 minutes a day in a familiar surroundings, maybe just around the house or out in the garden so he gets used to it, same as when you are introducing them to anything else like a collar and lead
- Gradually increase the time your dog wears the top and he should be fine to hit the street in the latest fashions