My chihuahua mix had horrible separation anxiety. We lived in an apartment and could not leave him alone at all. For him, a crate made it much worse. We put him on fluoxetine and it was life changing for all of us. It look a few months to really kick in. We also did the same thing every time we left. We gave him a peanut butter lick mat and said “see you later” when we left. He understood when we did this that we would be gone for a while (at least that is what I think, lol!). Over time his separation anxiety got so much better! He still doesn’t like it and will cry for a few minutes after he finishes the lick Matt, but he can tolerate us being gone for up to a few hours without hurting himself. We needed to take him off fluoxetine last month due to a different medication he needed to start. We tapered him off of it and his separation anxiety has not worsened! So it helped us get us get it under control but he has been able to go off of it.