Dog won't leave puppy alone

Hi
I have 5yr old dog and recently bought baby girl she is now 12 week old and they were getting on great but the last 3 days all rocko has tried to do is hump her and panting at her if he can't get to her they are now split up which is not what me or family want but he just won't give her a minute can any pleSe help with bit of advice cheers

How long have you had the pup now? Humping can sometimes be through stress, anxiety or excitement. Has his routine changed much since the pup came along? Is he still getting lots of one on one time?

Not much help sorry but it sounds the humping is more of a dominance thing rather than sexual. As I have never had 2 together I have no experience, sure someone who has will be along soon   

We have had Lacey 5 week and they were getting on great then out of no where fri he has become obsessed with her

Sorry, don't know if you saw my question. Has his routine changed in this time, and is he still getting one on one time? Separate walks and time with you etc. Sounds like he is anxious being away from her, but it's not healthy of course to get that stressed. Correct the mounting with a firm "no" and remove from the situation. Allow them to interact only when he's calm and balanced. How much is he walked? Biscuit mounts other dogs when she's over excited and needs a release of energy! She also humps puppies when she gets over excited by them. She's not trying to be dominant, she's just never been taught how to socialize politely. She still humps Max all of the time now, but we've continued to correct it and it's lessening.

Sorry must of misread 1st answer yes routine has changed as in he used to sleep on one of kids beds but now sleeps with Lacey in kitchen we take them out walking together as before obviously it was just him we keep everything as same as before just with both dogs now exept the sleeping part

No problem :)Okay, if the routine changed when she came I can't imagine that would be it. Is he trying to mount her constantly? Or are they having normal interactions inbetween?

It's definatly mounting then when he not with her he pines and pants constantly

But is he having normal interactions with her too? Playing/sleeping etc or just constantly focused on mounting her? Is he an entire male?

He is constantly focused on her he is still intact but didn't think that would be a problem till she hit season after about 20 mins apart he calms down then it all starts again when they meet again thanks for helping by the way

Hm that's a tough one.. If I were you i'd continue interactions with him on lead, correcting when he tries to mount and praising any calm behaviour. Give him a command such as "sit" when he's greeting her and only allow interactions if he's being polite. It may be a stress thing.. he may be feeling a little overwhelmed with it all. Are you planning to neuter him before she actually does come into season? No problem, that's what we're here for

Yes are getting rocko done next fri