According to the National Retail Federation, Halloween spending is expected to reach $5.1 billion this year or $64.82 for the average household. This includes candy, decorations, and costumes.
A growing trend for pet costumes helps to account for the increase in spending. Pet costumes average about $20 but can run as high as $30 or more. I think the Internet might be responsible for the growing popularity of dressing pets.
No reports are available on how pets feel about this, but mostly they seem to be patient about human eccentricity. There is absolutely no evidence that this dog was forced to wear a Halloween costume.