My older Daughter is back at home with her female 8 lb West Highland Terrier / Poodle mix (pretty obviously a miniture Poodle in the mix, not the Standard Poodle she was told) just about 16 months old.

We have 3 other dogs.   The oldest is a mostly Pit female (not sure what else, but not the boxer/mastiff mix we were told...) 60 lbs.   The two middle are Lab mixes (the Sire is the brother of the Pit we have)..also females.    The smallest was the runt of the litter...she's about 45 lbs at 3 years old, the other is about 55 lbs.  

Now, my Daughter's tiny dog plays well with them...not too aggressive, has fun inside and out.   Has for a while (both on visits and since the Daughter has moved back).

Now she's starting to hump the smallest of our dogs....out of the blue.  Nips at her (playful), then humps.   Our dog tolerates it.  

Why is it starting now?


And a food question...the older dogs get fed basic Dog Chow (do well with it, and it's not expensive for all 3...in theory, they're all my Younger Daughter's dogs, so she should be buying it...ha!).   My Older Daughter's Dog had some fancy dry food, but now she won't touch it...she eats the Dog Chow for the bigger dogs.    I guess we're stuck with her eating that too?  

Thanks for any ideas/suggestions....

The humping is her trying to establish dominance over the other dog.  Basically, both behaviors are insecurity based.  Once she gets her place in the pack established, much of the behavior will cease.

Got it...thanks.

Yup, pack and dog stuff.

Have a friend who’s male pointer dog “marked” (a.k.a. pissed on) his wife’s leg while establishing dominance.  She dominately caved his ribs in.

A reminder...... when she determines his place in the pack, make sure your the Alpha

As others have said, the humping is all about dominance.  The pack is very good at working stuff out as long as human behavior hasn't screwed up the structure from the get go.  If they're not trying to kill each other, you should be go to go.

Very much this...

Good solid advice sir.

I make a habit to always give mine the same exact food, at the same time and about the same size portions.

The first few times my rescue mutt got green beans tossed in with her kibble (cause everyone else got some) she ate everything BUT them. She may not 'love' them like the Dobie girls do but she eats them now and wont leave them behind. LOL!

Dogs will usually eat faster if they are all fed at the same time but I do suggest supervision and avoiding allowing any sort of bowl 'sharing'. Each dog needs their own bowl and if they go to stick their nose in the wrong one - YOU need to be the one to correct that.

Wish you luck with your pack.