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Reptile Egg Retention

My snake had her prelay shed and I can see four eggs in her. She started having contraction, but later stopped. What should I do?

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Q. I bred my 6-year-old female ball python to a het amel ball python on April 7. She had her prelay shed, so I assumed that she would have the eggs in a month or so. I can see four eggs in her. On this past Saturday she started having contractions. Later that night she stopped and has not started back up. Her current weight is about 1300 grams. I would also like to know the amount of oxytocin to give her if she needs it to help induce labor. Any help would be greatly appreciated.

A. Please make an appointment with your herp vet as soon as possible to have your snake evaluated. You didn’t say if she had successfully laid eggs in the past, which is important information.


There is obviously a problem if she started contractions and then just stopped. There can be several reasons why she hasn’t laid her eggs. To sort that out, you need your herp veterinarian to perform a thorough physical examination, take a complete history and then perform any necessary diagnostics (radiographs, blood tests, etc.).

I don’t recommend you try to give her injections of oxytocin, a hormone used to cause contractions of the shell gland. First, this should be performed only when recommended by your herp vet, and once you know for sure that your snake doesn’t have obstructive dystocia, which means there is some reason why she cannot physically pass her eggs.

Giving oxytocin to help expel eggs can be dangerous if an egg is too large to pass safely, or if there is some other problem preventing normal egg expulsion. In most cases, oxytocin works better when the herp is given injections of calcium prior to its administration. The calcium must be properly dosed and administered. I hope you understand this is not a simple procedure without risk.

In some cases where a female snake has not laid her eggs in a timely manner, the eggs will adhere to the walls of the shell gland. The longer the eggs are in the shell gland, the more adhesions will be created. In some cases, your herp vet will need to intervene and implode the eggs using a needle and syringe to aspirate their contents to facilitate their passage. Often, imploding the eggs breaks down the adhesions somewhat. Then calcium and oxytocin can be administered in the hopes that the imploded eggs will be able to pass. Sometimes it also helps to administer parenteral fluids (either under the skin or in the body cavity) because some of these snakes are dehydrated and need more than increased soaks to aid them in laying their eggs.

Sometimes there can be a low-grade infection in the shell gland. This, too, can cause adhesions to the eggs and gland, causing retained eggs. After appropriate diagnostics, the correct antibiotic must be administered to the snake to treat the infection.


I hope you can see that there is a lot more to consider when a snake retains eggs than just administering oxytocin. If the eggs are too large to easily pass, she could end up in more serious trouble, such as rupturing the shell gland, by giving her oxytocin. This is why I think you should find a qualified herp vet who can assist you in determining why she did not lay as expected and then treat the underlying problem as well.

Good luck. I hope you get viable eggs and the desired genetics for the color patterns you want! But, if there is a medical problem, solving that will hopefully ensure better success in the future!

Margaret A. Wissman, DVM, DABVP has been an avian/exotic/herp animal veterinarian since 1981. She is a regular contributor to REPTILES magazine.

Need a Herp Vet?

If you are looking for a herp-knowledgeable veterinarian in your area, a good place to start is by checking the list of members on the Association of Reptilian and Amphibian Veterinarian (ARAV) web site at Look for DVMs who appear to maintain actual veterinary offices that you could contact.