why do they fight

[fruitsalad]

out walking today with brother and sister jack russells they are 16 months old, when we passed another dog they started to fight each other, this is not the first time this has happened one of them will bark at a passing dog then they turn on each other any ideas why they would do this?

[wildwood]

Even with brothers and sisters there is a hierarchy order and another dog is a threat to this. Once the subordinate JR is wound up yakking at the other dog it becomes a threat to the dominant JR, so there is a biffo to re-establish the order.

You really need to get your dogs socialised properly as you will not be able to watch them forever and eventually will get you into trouble or they'll be hurt.

[Ermieox]

JR's can be particularly feisty and argumentative (small dog syndrome) and for this reason they need to know without any doubt that YOU are pack leader and that they are both subordinates. Until you have that pecking order sorted out you will always have problems with them. They clearly feel that you are their subordinate and that you need to be protected and then they can't decide which of them should do the protecting.

Neutering might also help if that hasn't been done.

Good luck!