Her dog was in heat, but she agreed to look after her neighbour's male dog while the neighbour was on vacation.   

She had a large house and she believed that she could keep the two dogs apart.  However, as she was drifting off to sleep, she heard awful howling sounds. She rushed downstairs and found the dogs locked together and unable to disengage, as frequently happens when dogs mate.
 
Unable to separate them, and perplexed as to what to do next, and although it was very late at night, she called her vet, who answered in a very grumpy voice. 

After she explained the problem to him, the vet said, "Hang up the phone and place it down alongside the dogs. I will then call you back and the noise of the ringing will make the male lose his erection and he will be able to withdraw."
 
"Do you think that will work?" she asked.
 
"Just worked for me," he replied.