Most people don't like pets or are allergic to them. Some may have bad history with dogs. For example, one may have been bitten or attacked by a dog. Not everyone likes dogs. Also, many may not enjoy working around dogs.
Some employees may not clean their pets. So their dogs might have bacteria going around the work area. Some owners may not get their dogs shots , so the dog could have any disease. Also, they the owner would constantly have to take their