Hi,
I am not a veterinarian. I am a snake keeper and breeder on a small scale. I have some experience with stuff like this. I will give my opinion on this, but take it as just that - my opinion and nothing more. Well here is my opinion on this situation:
If she looks as if there are eggs still inside of her there probably are eggs. She did not "forget" to lay them; rather she probably cannot pass them because they are too large, or because she has become too tired or weak to pass them. Here is what you can try, but by this time she may require a veterinarian:
1) Try to feel if there are eggs in her by palpating gently with a from about 3/4 of the way back on her body to cloaca motion of your thumb on her ventral surface. No eggs, no further action. (I would normally say to start at the mid body when doing this but you have fed her already. So remember that since you fed her there may be a lump from the mouse.) If there are eggs, move to number 2, if you are uncertain if there are eggs or one egg bring her to someone with a lot more experience.
2) Place her in a warm water bath for up to two hours. Start at 90 degrees Fahrenheit and allow the water to cool to about 85, then keep it at 85 by adding a bit more warm water as necessary. Make sure the water is shallow enough for the snake to be able to rest on the bottom and be able to easily have her head above water to breathe, a 3 to 4 inch depth should be good for an average sized adult California Kingsnake. The warm water apparently helps to relax muscle tissue and may help her pass the eggs. Check often, she may lay them in there and if you get them out really quickly they may survive. Take her out after 1.5 to 2 hours and place her in her enclosure with her egg laying box. Hopefully after a few hours she will have passed them.
3) Eggs can be gently palpated or pushed out by manual pressure. This is a delicate procedure, and if not done correctly it can harm the snake very badly. This should ONLY be done by one of two types of people: a long experienced snake breeder who has done it before, or by a QUALIFIED veterinarian, and by qualified I mean someone who is a vet with a lot of herp experience. Using this method often produces survivable eggs, but after your having waited 10 days, I do not know if any retained eggs could survive or if retained eggs could be passed this way.
4) The eggs can be gently pushed back to the cloaca, to the point where the egg can just be seen from the opening of the cloaca. A needle can then be inserted into the egg, and the egg drained of some of its contents. This sometimes will collapse the egg. This egg will likely pass by itself. Other eggs behind it may then pass on their own in the event that the egg nearest he cloaca was too large to have been passed, and that was the only one blocking passage of the others. THIS IS BEST DONE BY A VETERINARIAN who has lots of herp experience. Eggs retained for 10 days be not be able to be drained, an experienced herp veterinarian or very experienced breeder may know.
Bear in mind that if she is egg bound, and you have been feeding her, she may also wind up constipated because it will be hard for her to pass anything with any retained eggs in her. If you are fairly certain she is retaining an egg, do not feed her. If you think maybe she is retaining an egg but are uncertain, get her to someone with more experience than you for a check up, like a veterinarian.
All in all if the warm bath does not work by today, I would recommend getting her to a vet by tomorrow.
Next time you have a problem, don't wait ten days before seeking help, problems like retained eggs can result in the death of the snake.
Best of luck,
Glenn B
