Any unspayed female dog or cats in the stage of estrus (heat) shall be confined during such period of time in a house, building or secure enclosure, and the area of enclosure shall be so constructed that no other dog or cats may gain voluntary access to the confined animal except for purposes of planned breeding. Any animal that is in the state of estrus (heat) and that is not properly confined, or any such animal that is creating a neighborhood nuisance, shall be removed to a boarding kennel, to a veterinary hospital or to the animal shelter. All expenses incurred as a result of the confinement shall be paid by the owner. The owner of animals removed to the animal shelter shall be charged at the rate established from time to time by the animal shelter for routine confinement.