New puppy and old dog clashing. Please help!

[JesusDontWantMeForASunbeam]

We have a 14 month old staffy X Patterdale.

Yesterday we picked up an 8 week old border collie. Both bitches.

Older pup seems fascinated and horrified of new puppy. Lots of chasing and trying to fight. Separating each time and loads of praise for gentle sniffing etc.

New puppy is giving as good as she gets. Lots of nipping at dog and chasing her then running away.

Growling on both sides. Some snapping but older dog doesn't appear to be doing it in an aggressive way.

Will this get easier or have we made a hideous mistake?

Rare moment of calm yesterday

We had a terrier who was arsey with the new puppy. I wouldn't say they ever became best buds but after a few weeks they settled down. As you say, praise for positive interactions. Also try to give them time apart, and give the older dog some TLC as her nose might be a bit out of joint.

Your 'old' dog is still only an adolescent herself. Give both plenty of individual attention and don't leave them alone for at least the first two weeks. All things being equal they should be fine.

Hopefully it'll settle down with time. Out of interest, why did you get another dog? I can understand why your existing puppy has had her nose firmly out of joint

'Old' dog as in older dog not old dog 😊

She's happy. She sleeps on the bed, obviously new puppy doesn't. She's had lots of 1 on 1 time, treats for good behaviour.

They've just cuddled up on the sofa together and it's been calmer. Few mad moments where they're jumping all over each other but on the whole they are doing great.

We got another puppy because DDog1 generally seemed happier after being around other dogs, we wanted 2 dogs and the trainer I spoke to said between now and 2 was the best age to get one.

In hindsight we may have acted a few months too early which is why I asked for advice here.

Lots of nipping at dog and chasing her then running away

That may well be herding behaviour.
If you've got one whose inherited it, the herding instinct should be noticeable from 6 - 8 weeks.

I notice from the picture the collie pup appears to be short haired, could well be working lines.