How to train puppy to stop injuring older dog?

I have a 8 month puppy (Charlie) and a 4 year old dog (Chico)They are both smaller dogs and Charlie is particularly rough with ChicoWhilst on walks,Charlie will sprint and end up charging right into Chico.Its horrible to see, he had to go to the vets once before and the knock had caused liver damage.The obvious thing is to say stop walking them together but my older dog loves playing in the field with my pup, its just that moment where he charges him, for no reason at all!Also at home, they play rough and many a time I have walked in on charlie ripping the collar off Chico and trying to bite his paws.I have bought a crate for the pup to go in when I am not at home so he doesn´t hurt chicoIs this puppy behaviour? I feel he is just a bully.... Everytime chico tries to jump on the bed, charlie blocks his way, or when chico tries to get a toy to play with me charlie takes it off him.Even if charlie is preoccupied or sleeping and chico starts playing he jumps up and takes the toy off him.I´m thinking of rehoming him because he is just so mean to my dog!Can anything be done?Apart from these issues Chico loves charlie to bits, they play together, sometimes rough and sometimes just running together - Its really sweetThanks

I think that you allowed your puppy to tease the older dog from the outset. Now Chico is suffering from the consequences.Perhaps you can resolve this, by stopping either of the dogs jumping onto the bed or furniture. Dogs resent other dogs who are in an elevate position.To do this, cover the settees with cooking foil. Dog hate the noise that this makes when they try to jump up and they will avoid this in future. You should also close the bedroom doors.I have a box of toys, they are my toys and I use them when I train my dogs. Although my dogs have never fought, toys fail to interest them if they are left around on the floor.Separate them when you feed them and if you give them treat, put your dogs into different rooms.I hope that you can resolve this and keep your puppy.

Good luck to you. Have a nice day!