The only way to calm a male dog when he is in close proximity to an unaltered female in heat is to separate the animals so they cannot hear, see or smell one another. Many pet owners send the female to a veterinary hospital or boarding facility for the duration of her heat cycle.
When a male dog senses a female dog in heat, he might cry, bark, scratch or attempt to reach her in some way. This makes life difficult for the animals' owners, so it is best to separate them.
Pen the dogs in separate areas of the house
This strategy sometimes works in large houses. Close the male in one room of the house, then put the female on the opposite side of the house. Another option is to keep the female inside while the male lives outside. Never leave the female outside, as she may try to escape in her attempt to find a mate.
Mask the odor
It is sometimes possible to calm male dogs by eliminating the scent the female emanates during heat. Veterinarians often recommend a menthol spray for the tip of the female's tail.
Board the female
The distance created by penning dogs on opposite sides of a house is often not sufficient to calm the male dog. If this is the case, call a local veterinarian or boarding facility to inquire about boarding the female until her heat cycle ends. Many facilities offer this specific service for owners of unaltered pets.