I HAVE HAD PROBLEMS WITH MY BITCH ATTACKING MY DOG, SHE IS PERFECTLY FRIENDLY WITH PEOPLE BUT ACTS AS A APHA DOG WITH MY MALE. AFTER HAVING A BABY NINE WEEKS AGO THE FIGHTING WORRIES ME. ANY SUGGESTIONS WOULD BE APPRICIARED. SHE IS POSSESIVE OVER FOOD, AFFECTION...ETC.
HAD THE DOGS FOR 5 YEARS NOW

This could be jealousy.

Need to know what breed? and are either the bitch or the dog nurtered? If not when it the bitch due in session?
How old they both are? Are they both five?
When a new baby arrives, for dogs it's just like a new pup arriving. Ypu can get jealousy and the bitch may be over-protective to new member of the family.

BOTH SCHNAUZERS STANDARDS.
5 YEARS MALE, 4 YEARS BITCH
SHE'S ALWAYS BEEN AGGRESSIVE, BUT ITS WORSE NOW AS I CAN NOT SEPERATE THEM AND NOW THE MALE IS FIGHTING BACK.

Hi,
It is usual for the female to be the "top dog" in a house.
It is possible your female standard is being over-protective to you and your new baby.
Is she spayed? If not when was her last sesion?
Of the three sizes of schnauzers the standard is the origonal, therefore it's natural instincts are stronger.

hI there
she is spayed as she has always been lively. She got worse after she was spayed though She's always been jealous, shes not protective of me.
She is top dog but this is worrying

Do you allow her on furniture, do you schedule feed? if so who's fed first? Make them sit before you allow them to eat and feed her before him but only allow food when you say its ok- (I free feed). Maybe do alot more obedience training with her- could you be giving mixed signals to the dogs? When you come home who do you acknowledge first, walk, play ect with first? If she is top dog then you as an owner must make sure she gets all this stuff before him but she must learn that she comes first but after you-family- don't play/pet her when she wants it but only when you want to- Personally I would go right back to basic training- maybe keep her on a leash and give her her sits, downs and stays she wants to be rude drill her on her obedience---

Dozer always trys to challenge Junior (his dad) for top dog but I make sure he knows his place, mind you his daughter T-Bone is slowly taking over that role from Junior and Iam allowing that pecking order to come into play she tells him off and he backs down- where if Dozer tries to tell him off I'll have a fight so I just make sure Dozer knows his spot in the house. All mine are fixed except Junior he was our studd.

It is not uncommon to find that pushy bitches become even more pushy when spayed it seems the normal head girl position of the bitch becomes aggression rather than the more normal bitch behaviour of keeping everyone under control.

Unfortunately I can't offer a fail-safe way of dealing with it and going with her is probably the best way providing you retain control.

Is the dog castrated? If he is this could also exasperate the condition as castrated males often begin to smell like a bitch in season this can/will attract other dogs and make bitches see them as competition even when they are themselves spayed.

SHE'S ALWAYS BEEN AGGRESSIVE, BUT ITS WORSE NOW AS I CAN NOT SEPERATE THEM AND NOW THE MALE IS FIGHTING BACK.

Have you always seperated these fights?

How bad exactly are the fights, just lots of noise and the odd nip, or does your bitch draw blood?

Has the aggression escalated suddenly?  I would be wanting to get a vet check done on her, with full blood and thyroid panels to rule anything out.  Pain can be VERY well hidden by dogs, and hormonal problems (such as thyroid) can cause aggression.

5 YEARS MALE, 4 YEARS BITCH
SHE'S ALWAYS BEEN AGGRESSIVE, BUT ITS WORSE NOW AS I CAN NOT SEPERATE THEM AND NOW THE MALE IS FIGHTING BACK.

Hi,
What have you done in the past to stop her aggressive behavour? Is her aggresion only towards other dogs?
If she has always been agressive, it maybe a case that your dog has had enough. :-(

There is usualy something that starts aggresion! You could try a water pistloe to stop her or training, as soon as she starts being aggresive distract her with a comand using food as a reward.
This can be used if she is agressive or pocessive over food, do not give her her food in a bowl, but feed it to her only after she has done a comand, such as sit, stand or down.:-)
I would however for piece of mind get her checked over by a vet. Make sure you tell the vet she has always been agressive and it has got worse since a new baby has arrived.

Definitely get a thorough vet check :)

I've only skimmed very quickly as I'm going out, but she could be resource guarding and if so a good behaviour programme would help.

Try to identify the triggers. Use  management (ie childgates etc ) to control the environment/situation until you get professional help.

Good luck