My python is egg-bound...

Dear VPI,

My Indian python, Python molurus molurus, is not laying her eggs. Ten days ago she dropped one fertile egg and was incubating it. Two days later she left the nest for a different location where she dropped two infertile eggs. She abandoned those for yet another location where she continued to "shiver."

Three years ago she laid 24 fertile eggs without complications; however I fear the worst this time around.  Please advise! Rolf

Dear Rolf,

It can be a difficult decision. In most cases, I would assume that the eggs that are left are infertile and we would then leave the snake alone. Infertile eggs do not give the same hormonal signals to the mother, and they often are not all laid together, but instead are laid a few here and a few there. Sometimes it takes more than a year for all of the infertile egg masses to be laid.

The possibilities are that (1) most of the remaining eggs are fertile and there is a mechanical reason why the eggs are not being delivered (i.e. there is a twist or a torsion in one of the oviducts.) (2) the clutch is composed of all or mostly all infertile eggs.

What we know from experience is the following: You will gain little information from x rays. Administering oxytocin or vasotocin argenine is not a viable option-they both usually make things worse. Surgical removal of the eggs is not necessary if the eggs are infertile, but it is necessary if there are a lot of fertile eggs inside the female. All surgically-removed eggs are dead--don't even bother to set them up and do not do damage to the female with the thought that some or all of the retained clutch can be salvaged to hatch. Surgical removal of the eggs usually saves the life of the female, but almost always destroys her reproductive future. Eggs are most easily surgically removed if they are first aspirated.

As I said-if I feel that most or all of the eggs are infertile, we just leave the female alone and eventually all of the egg masses will be delivered.

If I am not sure that the eggs are infertile or if I am sure that most or all of the retained eggs are fertile, then I do the following. I take a 3" 12 gauge needle on a 100 cc syringe (big), stick the needle through the body wall at the paraventral level and into posteriormost egg and aspirate the insides (in other words, I stick the needle through the lower side of the snake into the egg closest to the cloaca and suck out the insides.) I attempt to suck out every drop of the egg and be as careful as I cannot to contaminate the oviduct with leaked yolk.

If the egg is fertile, then blood will be present in the stuff that comes out of the egg. If the egg is infertile there is no blood. Again, if the egg is infertile, I might aspirate a few more to be sure, and then leave the female alone. The shells of the aspirated eggs will be easily passed when the female is ready to do it.

If there is blood in the aspirated material, then with my veterinarian, we surgically go in to see if we can identify a mechanical problem. Starting at the posteriormost eggs we make about an 8" incision, open her up, and go in to look at the oviducts to see if there is a visible problem, like a twist or a loop in the oviduct. When an oviduct gets twisted, then usually blood flow to that part is blocked and the area of the problem can be identified because the oviductal tissue is damaged or necrotic. If there is a problem, we try to correct it. If we can't identify a problem and if all the eggs look fertile, we aspirate all the eggs we can see through the oviductal wall, we close the incision and then we aspirate all of the other eggs from outside of the snake. Then we sit and see if the female then begins to pass the eggs during the next month or two. At some point, if nothing comes out, I suppose we would feel forced to surgically remove the eggs; that has never happened, the aspirated eggs always have come out.

Good luck with your female. Perhaps these are all infertile eggs. If the female is bred late in the season, it sometimes happens that the first egg is fertilized and the following eggs are not. Maybe that is the case.  DGB