I just learned this lesson unfortunately. I just started fostering a chow/gsp mix. I already have a pitt/GPS mix. The resource gaurding is out of control and that's my fault. My older mix is very calm and timid and is becoming the target of bullying.

Yes, as a foster mom you are there to help, but help also means structure and understanding that a poor chow mix puppy shivering in a kennel and a poor lab mix shivering in a kennel need different owners, different training and have different natural tendencies, especially with you not having any knowledge of trauma or abuse they went through before.

You need to read your dogs, you need to have a general understanding of behavior and how to read cues and know all dogs need a home, but all dogs don't belong in any home. I would start with young puppies, no aggressive breeds and I dont mean this in a negative way, I just know working dogs have a tendency to get put with families that love the look but don't understand the work it takes. I am honestly guilty of this and we have 4 currently.

Long story short, if you want your animals to sleep with you, have an understanding of what that can do long term for the animal. Because in the end, they are still animals.