Just rescued a 2 year old Scottie male - brought him home saturday - that is full of life and fun and very well behaved.  My 8 yr old GSD female was OK in the initial introduction and 1st couple of days but has now turned nasty towards the new addition.  Outside they are perfectly behaved but inside around each other it is tense.  Toys are a big problem when they are around so trying to limit them and supervise their introduction slowly. Scottie loves toys and GSD could care less until the scottie is playing then its a game on and ultimately snarls and occasional fights. Making sure my GSD understands she is not being put aside but could use some tips.  Most of the time they are OK with each other but when they go at it they are both capable of hurting each other. So far no skin broken or blood spilled  !!! Both dogs ideal and gentle with people and scottie loves all dogs and people.  GSD would rather she was the only dog in the world.  In her early days with us she lived with a male GSD but he was the boss - now she is trying to impose her dominance but a lot too aggressively for my liking.
Rick

If they are posturing and not actually hurting each otehr then they will sort it out, though of course it is best to ensure they don't have things to quarell over,a dn that you ultimately are in charge.

I have found telling them both off works best ratehr than favouring one or other over issues.  they will end up comiserating with each other.

It is rare for long term problems with opposite sexes, as they really don't have competition for rank in the same way as with opposite sex.

How is the bitch with other dogs in general?

Thanks, I will try that out.  She is quirky with other dogs, loves some of them and others she doesnt get on with - normally when the customary sniffing is over with she is OK.  She is totally fascinated with the scottie and overall very pleased to have a companion - just wants it on her terms as the GSD can be.  The toys and particular spaces of the house seem to cause the issue - although the house is way big enough they both want the same spot.  Will keep you posted as to how it goes....

Personally, I would try to keep them separate inside for most of the day - the GSD is used to having her own space and you to herself.  She needs time to accept this Scottie and not for him to be forced on her.

Let them play together outside, since you say they are fine together when out.  At home, try to keep them in separate areas and spend time with each dog.  Allow them to see each other for a short period of time each day inside, with you supervising.  Try to keep this time always a bit shorter than whenever the first fight starts.  Gradually extend it and make it longer as they come to accept each other.

we had a spout of arguing over toys of course different situation as we has introduced a new puppy.
As she got older the eldest girl would take the toys off her which would cause bad feeling .
My solution was to remove the toys into another room would give them each a toy when I was playing with them then remove it afterwards ...this worked as no arguments over posessions and they were excited when they had a toy and me to play with.
They then found fun playing with each other frollicking and playing chase which I feel built up thier friendship .
I gradually left the odd toy lying around which caused no problem as she had accepted the pup by then .
(only toys I cannot leave out are tuggy toys as they get hold of each end and it seems to wind them up)

Roni

They have not had their toys so much today and had great fun together out on their walk.  Gave them access to four toys for an hour and a half and a few growls and that was it. Took the toys away and they played with each other for ten minutes and all been quiet and normal since.  No feeding problems so a good all round day almost over.  Toys seem to be the issue.  They are all chewy toys.  Scottie is the dark destroyer of anything remotely soft.  Going to keep the toys limited over the next few days and gradually increase.  This dog is a credit to rescue dogs though - what luck for us - vet is well impressed with him and so are we and our GSD bitch is getting there !! Thanks for the advice and helpful suggestions.

so pleased you had a good day today ...hopefully things can only get better....

Roni

Think youve hit the nail on the head there. 

Toy envy is a terrible thing.  Sound daft doesn't it but I have found the same, introduce a new dog who doesn't know the rules and the first thing they do is try to play with their own new toys and wham, resident dog suddenly wants them all for itself even if they never held any interest before.  I have done as suggested by others given each dog its space and own toys, only allowing certain safe (as in doesnt cause an argument toys) to be left out.

There only human are they.