Cora's puppies

We have started to wean Cora's puppies and have removed 4 from her. All but one of these puppies are very large and having them all with her, all fighting to feed, was clearly taking it's toll. They are all doing well except the smallest who sadly appears to have paralysed hind legs. Cora is very protective towards this pup and she gets very distressed if we try to remove her. For now we have left them together but this little girl is really not in very good shape.