I developed an awesome macro the other night to do this shitty task while afk.
In razor, make a new macro and title it whatever you want. Mine is called killmare. Dont record anything on it. Open the razor folder, open the macros folder and locate this file. Open it with notepad and copy in my text (must have razor/uo closed)
Code:
!Loop
Assistant.Macros.WalkAction|4
Assistant.Macros.WalkAction|4
Assistant.Macros.PauseAction|00:00:01
Assistant.Macros.SpeechAction|0|26|3|ENU|2|17|93|SynysterGates kill
Assistant.Macros.WaitForTargetAction|30
Assistant.Macros.AbsoluteTargetAction|0|1|346655|4136|604|27|116
Assistant.Macros.PauseAction|00:00:05
Assistant.Macros.WalkAction|0
Assistant.Macros.WalkAction|0
Assistant.Macros.PauseAction|00:00:01
Assistant.Macros.PauseAction|00:00:01
Assistant.Macros.DoubleClickTypeAction|3617|True
Assistant.Macros.WaitForTargetAction|30
Assistant.Macros.AbsoluteTargetAction|0|2|346655|4136|604|27|116
Assistant.Macros.WaitForGumpAction|81425088|False|300
Assistant.Macros.GumpResponseAction|1|0|0
Now save! Open up razor and your macro should be complete. You will need to re-target the mare and remove the action of 'synystergates kill' and replace it with 'yourpetname kill'. Do this by 'begin recording here', and command your pet to kill (i like it better than all kill).
Next, you'll need one mare due for killing, dragon/ww, bandages and two boxes. Take the mare and place it in a pen. Put the two boxes down on the ground behind the pen's doors so the ghost doesnt walk to you for any reason. Take your dragon/ww and put into a different pen. If you have difficulty getting it in there, have it follow you into the pen, command it to stay, walk to the front of the pen, command it to come then command it to stay again. It has to be fast. I type in 'all stay' first, I hit my 'all come' hotkey then instantly hit enter to say 'all stay'. If done correctly it should of moved forward and the pen door will have closed.
For the macro to work correctly, stand facing the pets in the nook of the pens. Keep about 200 bandages on you and it should run smoothly while you're away (no spare vetter required!). The only snag will be when the bandages fail to res the mare. It will set off a 5 minute timer then start the macro over. You'll have to edit the timeout, and set it to like 20 or something low. Whatever works for you. I also recommend checking in every 45 mins and picking up and setting back down the boxes so they dont decay if you can't lock them down. But if all is well, your mare should be zero'd out by then.
Any questions feel free to ask and i'll answer as best as I can or demonstrate. Happy killing!