One of the many reasons people who would dearly love a dog but can't, is because they are likely to develop an allergic or asthmatic reaction, even the mere presence of a hairy critter in the room can set them off.
Approximately 10% of the population are allergic to animal fur, specifically cats and dogs. For parents with susceptible young children, or those already suffering from conditions like asthma this can be a real worry and so reluctantly they decide not to bother getting a dog at all.
Whilst there are no dog is 100% hypoallergenic, there are many breeds which mitigate the worst effects for the following reasons:
They are virtually non shedding or minimal shed
They have ‘hair ‘rather than ‘fur’
They produce less dander or allergens than other breeds
Shorter fur attracts less allergens from the environment