Loose your mother in law. Things will only get worse. I’ve been there. Mine came for a weekend visit and stayed 8 years.

Dogs, or rather pets in general, are considered property. That is plain and simple theft. Depending on the breed and lineage of the dog (meaning it's value) and your state's established minimums this could be considered GRAND theft/larceny. On top that, grand larceny is almost always a felony. You need to get rid of your wife AND your mother-in-law. She is okay with this behavior? Get rid of that crazy family and find someone better. This woman has no fear of consequences, she is capable of ANYTHING and your wife's response is, "But it's my mom."? Contrary to popular belief family is only as strong as the people involved.

"She has no respect for me. If you protect her, then YOU have no respect for me. You'll be hearing from my lawyer about how best to make sure your mom is the only one in your life, since you respect her more than me."

Your MIL is crazy. She had no right, absolutely none, to give away your dog. Apart from how morally wrong this is, she had committed theft. Also, what kind of person would do something like that?! She completly dicarded your feeling/opinion on that."One less mouth to feed", who asked her opinion, is she paying anything? Same with the mail "I thought it was junk mail" seriously, she can't make the difference between junk mail and serious mail? Have a talk with your wife, because mother or not, her mother/your MIL is going to ruin your life if nothing is done. Tell her to mind her damn business but honestly I think she kind of forgot that she is living in YOUR house, on YOUR money, not the other way around. You need to sit her down and have a talk with her. Either that or she is doing this purposely because she is trying to "assert" dominance (I can't find a better way to say it, she basically does not like the fact she is relying on you and your wife, so she is trying to have a bit of control over you by being a jerk). I hope you got your dog back (again, no matter who she gave it too, she had no right to do that, so it was theft, whoever she gave it to can't keep it, that's the law)

Time to get rid of the mother-in-law. It's one less mouth to feed.

Sounds like dementia. Take her to a doctor

You are well and truly screwed. If your wife is like mine, any attempt to get rid of your mother in law will result in getting rid of your wife as well. Good luck.

Why does your wife have to kick her out? Why can't you do it?

This is a tough one. If your wife wont help you then you have to take matters into your own hands. Talk to your MIL, and tell her she has 2 options. Move out, or I'm calling the police to report theft. Tell her you will even help however you can to get her out. If she turns around and tries to pit your wife against you, well then you might have to put your foot down.

Did you get your dog back?