There's much curiosity about the safety of sleeping with dogs in bed. Of course the love for a pet can override possible issues. Now reasoning has been posted and overall it is safe.
This from the department of disease control, “There’s no doubt that dogs can carry bacteria and parasites that could do us some harm, but generally I think the risk is very low. You could argue that being exposed to some of these organisms might actually do you some good – people who have grown up with pets and other animals tend to have fewer allergies, for example.”
There could be some partner issues, “In such satires, the husband feels that the dog on the bed is denying him what should be his by right – his wife’s company and attention, and therefore the sexual gratification she should be providing,”
Ha, there is some talk about spoiling the dog and it taking over the bed. More here.