My dog keeps attacking my other one

[ElSmi]

hello i was wondering if anyone could help me, i have a staff (girl) and a border collie (boy) i have had the staff for a long time but only just got the border collie a couple of months ago.

they will play together all day sleep next to each other and there fine BUT every now and then my staff with go for my border collie for no reason they can be both sleeping then suddenly she will go for him, today he was just standing next to her sniffing the floor then she went for him this has gone on for a while but sometimes it will be a week before it happens again he doesn't go for her back tho.

she only goes for him but once she's been shouted at and told to stop she will stop and not do it again until later on

i hope people understand this as i'm not sure how to explain it

thank you in advance.

 

[Oreo]

Hi,

How were they introduced?

Did you introduce them on neutral ground or bring the new dog in straight away.

It maybe the older dog is still getting used to sharing his space with another.

I wouldn't leave them alone until you know for sure it's settled down completely.

 

[PuppyLand]

Hi,

I would take the dog to the vets and get it checked out in case there is some underlying cause, and also explain to the vet what is happening, so the vet can give some advice. Best of luck.