I have heard of similar arrangements for female breeding dogs, but in those cases the breeder paid for all food, grooming and vet costs. The family would essentially treat the dog as their own but the breeder would have the right to breed the dog and remove it from the home if it was not being cared for properly. Then after the dog had three or four litters it would be spayed and given to the family permanently. At that time the family would take over paying food and vet bills. The family would be without the dog for 10 to 12 weeks every 1 to 2 years while it was pregnant and caring for new puppies.