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Alpha-2 agonists and stressed turtles The table below illustrates that the alpha-2 agonist Domitor (medetomidine), when added to oxytocin + Lutalyse (PGF-2), seemed to be no more effective with RES than oxytocin + Lutalyse alone.  However, that poor outcome was caused by the sequence of injection.   Because we gave the Domitor after the mix of oxytocin and PGF-2 the laying process was disturbed.  We would learn later that we should have given the Domitor first. Years later, when working with softshells and snapping turtles, and injecting the alpha-2 agonists first, the alpha-2 agonists proved to be critical to achieving a successful outcome.  We will detail those result later under the heading “The drugs we tested on SSS (spiny softshell turtles).” Shortly after we first worked with Domitor it was removed from the market and replaced by the isomer Dexdomitor (dexmedetomidine) which was about twice as potent as Domitor.  After that change we experimented with Dexdomitor and two other alpha-2 agonists: xylazine and Sedivet (romifidine).  The first challenge was to determine the appropriate dosage range for our trials.  We did that by reviewing the recommended doses for various small animals and then testing a range around those varied recommendations.  Then we…

 Less common species we worked with on the turtle farm We had limited opportunities to work with small numbers of other North American turtle species at the Concordia Turtle Farm.  Usually we were only able to induce a few of each species each year so the methods we used evolved over time and the numbers of animals we induced of any one species were low except for the spiny softshells. From 2008-2019 we injected over a hundred turtles of various other species besides RES (razor back musks, snapping turtles, and a variety of cooters, sliders, painted and map turtles) with variable outcomes. Because of the limitations of low numbers there were few observations of value.  The table above deals with the yellow bellied and cumberland sliders.  These species seemed as responsive as RES to 1.5 mg/kg of Lutalyse.  The table below details the results with 21 snapping turtles.  Note that the eight turtles that received an alpha-2 agonist laid all their eggs.     Sabine map turtles (Graptemys sabinensis), as shown below, appeared around the farm during rain storms. The barriers around the ponds were porous and these small turtles could slip through and wander freely. Because of their small…

Methods to determine the number of eggs in a clutch   During our work with RES we depended on palpation to determine how successful an induction had been. An induction was only classified as successful if no eggs were palpable afterwards. In 2009 we did a study and palpated 46 RES after induction.  There were three examiners.  Results were checked by ultra-sound. The outcomes in the table below showed an accuracy rate around 93%.  That is, 93% of the time the examiner would be correct when checking a turtle for eggs post-induction. When we decided to work with spiny soft shells (SSS) palpation was not possible because of their large size. We tried ultra-sound but that could only tell us if there were eggs, not how many eggs there were. So we turned to x-ray as our method to determine the number of eggs in these much larger turtles.  Our funds were limited but we managed to secure the loan of a handheld, portable, Nomad dental x-ray machine.  This machine had a low output so it took 3-4 seconds to get a good film.   Each spiny soft shell turtle had to be washed before being x-rayed. They did not…

Working with spiny softshells turtles   Spiny softshells (SSS) are large and aggressive. They are also fast and hard to catch; even when using drift fences on a turtle farm! SSS are much too large to palpate for eggs so we had to x-ray each animal to determine how many eggs they were carrying.  Before any injections were given each turtle had to be wrapped in towels to protect the turtle and ourselves.   An examination of the anatomy of the SSS showed two mechanisms that enabled them to retain their eggs.  One is a powerful sphincter at the end of the oviduct much like the cervix in humans.  This is illustrated below.                         The other mechanism that enables egg retention is a weaker sphincter at the distal end of the everted cloaca as shown in the figure below.  Both sphincters must be relaxed for oviposition to occur. In addition to finding the right drug to relax these sphincters, we had to determine the dose and the the sequence of injection; should we give drug #1 first, drug #2 first, or should we give them together?.  If we gave…

The drugs we tested on SSS Although we doubted oxytocin used alone would be very effective on SSS we tried it at two dosage levels, after different holding periods, with a low success rate in all cases, as shown below.     After trying oxytocin alone we ran a trial of a mix of oxytocin and Lutalyse with both drugs being injected at the same time.  Forty four animals were involved.  It took nine working  to collect and process this many animals so numbers were low in every category.  As you can see from the four tables below the success rate seemed higher on the stat day than on days 1, 2, 3 and 4.                                                               Even when all the results were pooled without specifying the day of induction, as shown below, none of the combinations of oxytocin and Lutalyse were very effective. Cytotec is misoprotol or prostaglandin E1. This is a drug that can induce abortion in mammals. The details of how we used it are described previously under…

Side effects of drugs used with RES and SSS Oxytocin used on its own has two significant side effects.  One side effect is that it interferes with the next ovulation in species that lay multiple clutches.  That means there is often only one clutch per season where there might have been three or four.  It also causes false nesting;  a behavior where the female attempts to nest after a successful oxytocin induction even though she’s carrying no eggs.  This is a big danger for wild turtles who must face the threats of automobiles and predators when they emerge from the water to lay their eggs. We addressed both these issues. We were able to test Lutalyse in several ways to see if it interfered with the following ovulation.  One method was to follow up labeled RES on the Concordia Turtle Farm.  We applied tree paint to each RES with a code that referred back to the day they were induced.  The problem with this method was that the labels deteriorated rapidly.  This happened despite each animal’s carapace being washed with water and then with rubbing alcohol before being labeled. After three weeks (the average period between clutches)  the label was…

Repeating an induction after the initial induction failed Previous work had suggested we would get the best results with a reinduction if we held an animal for 3 days after the initial, failed induction. This was difficult because there was only limited space to hold the turtles, especially the SSS which had to be held separately (because of aggression) and required a very large tank. Once we started using Lutalyse with RES there was only a 6% failure rate with the first induction so turtles to be reinjected were hard to come by. However, the failure rate with Lutalyse alone was 43% in 2016 with RES stressed by malnutrition so we had plenty of turtles to include in a follow-up study that year. When these RES were reinjected with Lutalyse and Sedivet three days after the initial failure we had a success rate of 81% as shown below. In 2013 we were inducing SSS with a combination of Lutalyse and oxytocin plus Dexdomitor. We reinjected three of these. Two were reinjected after two days and one after three days. They were reinjected with the same dose of Lutalyse and oxytocin plus Dexdomitor. All three SSS laid all their eggs with…

 References The references here relate directly to the trials at the Concordia Turtle Farm.  Additional references that focus on earlier work and reproductive physiology are listed as part of the section of this web-site labeled as “2007 article.” Alkindi, A.Y.A., Mahmoud, I.Y., Woller, M.J. and Plude, J.L. Oviductal morphology in relation to hormone levels in the snapping turtle, Chelydra serpentina.  Tissue and Cell 38:19-33. Carr, J.L., Messinger, M.A., and Patton, G.M.  Nesting behavior in three toed box turtles (Terrapene carolina triunguis) following oxytocin-induced oviposition.  Chelonian Conservation and Biology (7):124-128. Cipolle, M.D., Zehr, J.E., and Reinhart, G.A.  1986.  Effects of autonomic agents on rennin release in the turtle Pseudemys scripta.  American Journal of Physiology 251:R1103-R1108. Ewert, M.A., and Legler, J.M. 1978. Hormonal induction of oviposition in turtles. Herpetologica 34(3):314-318. Feldman, M.L. 2007. Some options to induce oviposition in turtles.  Chelonian Conservation and Biology 6(2):313-320. Figler, R.A., MacKenzie, D.S., Owens, D.W., Frank, J.C. and Huffaker, J. 1995. Labor induction with intravaginal misoprostol versus intracervical prostaglandin E2 gel (Prepidil gel). American Journal of Obstetrics and Gynecology 173 (4):1137-1142. Gross, T.S., Guillette, L.J., Jr., Gross,D.A. and Cox, C. 1992. Control of oviposition in reptiles and amphibians.  Proceedings of the American Association of Zoo Veterinarians…

Acknowledgments We would like to thank Jesse, Avis and Davey Evans, the owners of the Concordia Turtle Farm in Wildsville, Louisiana, for their wonderful support during the years of our study.  Their unflinching generosity, insight, and tolerance will always be deeply appreciated.  They made our times at the Concordia Turtle Farm one of the highlights of our lives. We would also like to thank Dr Alvin Atlas and Jill Atlas for their help securing supplies and with field work, Dr John Carr for his assistance with the ultrasound machine and access to university lab facilities, and Dr. Elliot Jacobson for his help in providing access to research papers.