We thought we had another month, but little Parson Russell Terrier mom gave birth today to three healthy and one very preemie stillborn. Mom is very proud. Chug would love puppies but mom attacks him on sight. However, Gaia, Rue and Eponine were welcome to observe. Gaia considered stealing a puppy, and after a short growl exchange, Gaia moved away.
UPDATE: at 6:45, nearly 12 hours after labor began, the momma dog popped out 3 more puppies. Sadly the first of the three was stillborn, but the other two are healthy and strong.
Mom and babies have been moved to a tent of their own, with view obstructed so Mom won't get stressed out by the other animals. This also lets Chug roam free of the crate he had to stay in all day because mom attacks him on sight, but now that he has his freedom, he's still too afraid to come out of the crate.