I assume that Roge is not spayed.
Is this secretion from one or many of her nipples?
If this is from many or most of her nipples then I think that she is experiencing a false pregnancy.
Dogs, unlike people, do not go through menopause. They cycle until they are spayed or pass away. Their cycles may be much different when they are older, much more time between cycles, or almost silent heats with very little discharge and external signs or in some cases the discharge may be very heavy if they suffer from endometriosis or develop a pyometra (infected uterus).
A false pregnancy can occur after a normal heat cycle, even without a male being anywhere near her.
This is because hormonal changes in a dog are very similar whether they are bred or not.
In a pregnant dog the female's hormones fall off and the pups respond with their own hormones which leads to delivery.
In a nonpregnant dog there just isn't any pup stimulation. But some dog's bodies get confused and they feel like they are pregnant.
They will often pick a toy to mother, may even build a nest and produce milk.
We do know that if a bitch's mother had false pregnancies then she is likely to have them as well. And once they have one false pregnancy they are likely to have one with every heat cycle where a successful breeding doesn't take place.
It doesn't mean that she isn't fertile or that there are hormonal problems with her. She could be successfully bred on her next heat if you wanted to.
If you aren't going to breed her then I do recommend spaying her to avoid subsequent false pregnancies.
However there really isn't anything that you can do now to change her behavior or her milk production now, except making sure she isn't licking her mammary glands. Milk production is based on demand so if she licks and empties the glands she will produce more. That's why sometimes only some of the glands that the dog can reach to lick produce milk. Even spaying her at this point won't change things now as the hormones already produced and circulating in her body are the problem. Her behavior will change naturally as her hormone levels decrease. You can certainly try and distract her with walks and play as some bitches do seem to come out of it a little quicker if we can distract them. But spaying her after this false pregnancy will prevent further episodes.
If the affected gland has a firm mass and there is only one producing milk then this may be related to mammary cancer.
That should be addressed promptly as 50% of mammary tumors are malignant.
And if she is running a fever and feeling poorly then she could be developing mastitis, and that too should be addressed promptly by a veterinary visit for an exam and antibiotics.
But if she seems to be nesting, and eating and drinking normally without a fever and multiple glands are producing then this is likely a false pregnancy. Then you need to make sure she doesn't lick and give her time and this should resolve over a couple week's time.
Please let me know if you have any further questions.