i wouldnt use a lunge lead, scared of dog going through horses legs, have done it (off a pony) with short lead looped through collar so can release
and had dog loose
I agree with the above 58 years experience with horses and dogs...don't do it. Too dangerous for all three of you. Of course you are young so you will try it. So good luck.
Love you
Suzi
PS off tomorrrow (yes sunday) for an MRI on my back because of doing something stupid on a horse that was standing perfectly still and still was when I found myself flat on my back!
Suzi
If your dog already walks to heel off the lead, you should find that when you are ridden and give the heel command, he heels your horse. If not, teach him on the ground first! Same goes for sit command.