Ive had a 6 year old toy bichon for just over two months now and my rather large bichon since 8weeks old for 4 years up until today was all going well but the newer dog decided to lunge off the sofa after my poor baby snapping at his face she even chased him to the other side of the room. He didnt show any signs of aggression back and just coward his head down we had to pick her up and remove her from the room i am now worried as to why this has started?? Any suggestions or questions will be appreciated.thanks

are both still entire/castrated/spayed?

Bothcastrated and spayed

Sudden aggression like that makes me think either medical (pain usually), or possibly guarding something (or both).  What were you doing at the time?  Any toys, treats etc in proximity to either of them or in the room?  Any hints of guarding behaviour from her previously?

Hi there come to think of it i was eating a packet of crisps she usually snaps him away if theres food but this prticular time she lunged and chased to the point we had to remove her fromthe room. I feed them together dinner time shes fine other food not
So good

No much previous history as we rescued her from an elderly lady other than that shes been fine altho likes to have my lap all the time which im trying to put a stop to