
My Kizi (RIP) was awful like this around seasons I called her my anorexic and this in a breed that tends toww4rds greed.
She improved then she was mated ate well while rearing pups and after, but went off food again when she had her next season.
In the end I just stopped worrying about it and she improved the older she got. She didn't carry good weight until she was four or so.