Resident dog's anxiety may be worse after foster leaves
Advice needed. My resident dog (male, beagle, 9 years old) seems to have worse anxiety with being left alone after a foster leaves. At the beginning of the year, our other dog passed and we've fostered twice since then (for 3 weeks and 1 week). This year he has seen 3 dogs leave and never come back.
I've noticed recently that he has been slobbering a bit in his crate and maybe licking the crate when left alone (he voluntarily hangs out in his crate when we are home). He has always had some anxiety when left alone but it seems to have gotten worse. I haven't been tracking (will start to do so) but it seems like this behavior increases after a foster dog leaves. He ignores treats/kongs when we're gone. I have not noticed any other behavioral changes other than some sadness when we lost our other resident dog but he seems to have gotten over that.
I am looking for advice on (1) whether fostering is too unstable for him and maybe we should stop fostering or adopt instead and (2) any ideas to help decrease his anxiety. We are going to give him longer walks before leaving and test out leaving him uncrated. He also has a general vet check up next week. Thanks in advance!