Can a greyhound be depressed?

Hi, this is Cooper.  I haven't written because my foster mom told me I was so sweet and adorable that someone would want me soon.  We had a few close calls, but turns out that I may be a bit too active for some people.  Well, yesterday, I went to the greyhound picnic and got to see my brother and lots of my cousins.  I had a great time and was on my best behavior because my foster mom said someone would meet me and fall in love.  Well, I am a bit shy and it turns out that is not the best way to get a new home.  The other pup that was there looking for a place to live found a home, but not me.  I am so sad today.  My foster mom says I look a little depressed.  But, she told me just hang on, someone will love me and see how wonderful I am.  I really am a good pup.  I love my people a lot and I have a funny personality if you just give me some time to settle in and figure things out.  So, if you have some time and patience, please come visit me.  I promise that after 2-3 weeks of living with me, you will love me as much as I love you!!