I have a 2.5 year old collie bitch (not spayed as I was hoping to have a litter out if her at some point) . I have had her since she was 7 weeks old, and she is a fabulous working dog, very driven but has always tried herding the others. However the other bitch (8 year old mongrel) is constantly badgered by her, my bitch just won't leave her alone. Now its escalated into fights between them and I am worried one of them will end up hurt. Yesterday, someone came to the door, the next thing my dog had hold of the mongrel and would not let go, eventually she broke off and I managed to get the old dog out. She stayed in my room last night. I don't know what to do. The old bitch doesn't need this at her time in life, my cvollie will constantly hound her out walking, so now we have started walking them seperately. My bitch doesn't bother with my dogs, so I wondered whether getting her spayed may help.

I really don't want to rehome  my bitch, she is mbaby, but I also don't want them getting hurt. Help.

my cvollie will constantly hound her out walking, so now we have started walking them seperately. My bitch doesn't bother with my dogs, so I wondered whether getting her spayed may help.

Getting her spayed will make no difference to this behaviour, even if it is her jostling up the pecking ladder spaying IME changes nothing.  On the walks, you can continue to walk them separately, probably for the best, or distract her from  continuing to harass your older bitch by training sessions or carrying a ball, young BC's need a distraction otherwise they will revert to what they were bred to do, they will round up and nip the heels of animals as well as people. ;-)

You need to protect your older dog from her whether this is her excitable breed trait or for hierarchy reasons, if you are working her you should have her trained pretty well to commands by now an 'off' or 'leave' really should be being obeyed on the walks, I can understand in the home as you often do not get the chance to spot the triggers happening quickly enough, but on walks she should be compliant, I would take a ball for her to re-focus and also implement those commands.

If this is hierarchy trouble, your older dog is in danger of being badly hurt, you really cannot do anything to stop it apart from keeping them separated and being vigilant at all times. Being the most intelligent breed she is going to want to be in charge here, the boys will know it already and unfortunately even if your other girl is submissive to her and would happily allow her to be the alpha she may look upon your other girl as being disposable, dogs can be like that..... and BC's can be a reactive breed who will nip or bite first, it is extremely sad when this happens but if this is the case, I really would never leave them alone now ever!

I would continue to keep your BC very busy with other tasks and play and just keep them separated in the home for your older girls sake, it's not worth the risk.

This may not be heirarchical but a longstanding problem that has now reached breaking point.  You say the older bitch is 'constantly badgered' - how long has this been going on?  I have had clients before in this situation, most notably a woman who allowed her younger dog to harass the old in the way you describe until one day there was an enormous fight and the dogs could no longer live together.

Indeed I'm in a similar position myself at the moment with my collie pup - like yours, she is very driven and spends most of her walks showing herding type behaviour, stalking, eyeing and flanking my other dogs.  If I allowed her to, she would badger my youngest boy (who is 27" and 34kg to her 20.5" and 15kg, so it's nothign to do with size/stature) relentlessly on walks, and for a time was trying to do the same with my youngest bitch up from her.  It's got nothing to do with dominance - it's just a pushy young upstart of a farm bred, working line collie playing in a way that she thinks is tremendous fun.

I've had to work very, very hard at her recall, 'away' (for when she's started to badger) and 'leave' (for when I catch her about to start) cues and gradually, she's starting to leave them alone of her own accord and just run with them.  If I were to leave her then one day, there would be serious trouble I am sure.  Linc is already not keen on walking past me sometimes as he can see her in front of us stood poised to start annoying him.  My friend has already has this problem with her own working line collie doing exactly the same thing with her older collie bitch, and the younger has been injured by the older because of it - and I can tell you from observing the two at home, there is no heirarchical dispute involved whatsoever, it's entirely inappropriate play.  Getting spayed will not help it - this needs training.