Can they just not come in?

Ruby

She's a month late.  Ace is looking at me like I can do something, and I don't have any answers at all.  What a lousy time to not come in season! She's been as regular as a clock for the past 3 years and now, after permission from the Ball and Chain and all the hoops to jump through, she decides to not come in to season.  The vet says she appears close, and I've checked her out so much she is starting to turn away from me and jump up on her front legs to get her rear end in the air as I approach! I'm thinking some more investigation as to dogs and estrus cycles, etc., is in the cards here.