in heat

Question
My female yellow lab is in heat and was in her pen last night.  I woke up to find a jack russell terrier in her pen with her.  He had gotten throught the fence and was in her dog box.  My lab was laying in her box with the male jack russell humping her.  Is it possible for a jack russell to breed a lab?

Answer
Unfortunately, yes.  I get beat up sometimes for warning people that they need to be very careful because dogs will do almost anything to get together.  While your fence may have been quite secure to hold her, it wasn't good enough to keep him out.  If they weren't tied when you disturbed them, It is unlikely the breeding will take.  It is too bad people that have made a good effort to prevent accidental breeding, still get caught.  It might not hurt to have her examined by a vet.  All sorts of things can go wrong besides an unwanted litter.