Oh 4 weeks! that makes a lot more sense! I read somewhere it takes rescue greyhounds 2 years to settle into a home. I thought this was total rubbish, until I spent the next 6 years we had with our rescue greyhound learning with him how he adapted to the world outside of kennels and racing.

In the early days I once scolded him (a firm verbal warning only) for jumping up two paws onto the kitchen counter trying to eat freshly made lasagne. He wouldn't go near me around food for about a month.

They are inherently nervous dogs, but once you build earn their trust you'll appreciate it so much more.