I think it's unfair to the animal if you dress them up in clothes all the time. I think it's acceptable for a smaller breed dog to have a sweater when it goes out in the cold but only for that time period. I also think it's acceptable for a toy breed to wear something for a short period of time if they are cold.
I work at an animal hospital and I have seen animals suffer because people think it's cute for Fluffy to wear baby clothes. We had a client who's dog got very dry skin from wearing clothes all the time. His skin couldn't breath and he was always scratching. Luckily, after a talk with her she stopped and she applied a leave in conditioner to the dog's fur. This helped the skin go back to normal.
