My opinion is that an adult racer does not need to be this chunky. The snake in the pic is already starting to take longer between meals at about ten months of age, and I anticipate she will be a proper weight when she comes out of hibernation in spring of 2012. She will most likely continue to feed aggressively for the rest of 2011, but next year I expect her to settle into a more snake-like schedule, with feedings about every four to six days, and occasional breaks when she will not eat at all for a few weeks, especially during midsummer.
I would feed your snake all she will eat until she decides to slow down. Your snake has fallen behind in food intake and will self-regulate to catch up. Racers are not like boas, ratsnakes or kingsnakes, in that they don't get overweight the way more sedentary species do. Feed small meals, perhaps one or a few mice at a time, as often as she wants to eat. I'd offer seconds until she stops on her own, but not more than three adult mice at one sitting. That may be every day or every few days until she gains some weight. Remember that she is expected to refuse food as she settles into a schedule that satisfies her, so when that day comes, don't worry that she's sick--she's just had enough.
Once she has good weight, she can skip a meal every now and then and you can get your own life back. You can go on vacation and all the things snake keepers expect to be able to do, based on the philosophy that snakes don't need daily care. Sighthunters are much, much more demanding than other snakes but they still leave plenty of time for keepers to relax. A good enclosure will make all the difference. Full-spectrum light, strong air exchange and a warm basking site at one end of the cage with the rest of the cage in the low 70s or upper 60s will set you free to enjoy your racer instead of having to constantly tinker with her care to work around shortcomings in housing.
Racers are very intelligent and emotional animals. They recognize their primary caretakers and learn to snatch food from forceps as soon as the cage door opens. I had one that was so crazed about eating, he used to shake his dead mouse so hard he bounced his head off the front and back of his cage. One time he shook the dead mouse right out of its skin and crawled around the cage looking for it with a tuft of white mouse fur sticking out of his mouth, looking like a Santa beard. I used to call him The Mangler. He was sent to a nature center that exhibits native Midwest species, and is doing very well. I'm not sure how well the keepers are doing.
I keep many species of snakes but there really are no others quite like racers, coachwhips and indigos. It's more than a just a keeper with a captive--it's a relationship.
