I would like to share a method (gastric suction) which avoids, in most cases, or minimizes the death of animals in diet studies.
Hi Andre, what about the analysis of excrement. its are impossible in your species. I know that collection is a difficult sometime but it is nothing invasive. In herbivore species is a challenge.
Hi Rafael. Thank you for your answer and interest. I agree, with excrement analisys is difficult to study lizard's diet. Thereby, I developed the gastric suction as an alternative method, which I'd like to share with colleagues. Regards.
Ok I would like to know. Do you published the method?
I have been doing some excremenet analysis in feral catsand dogs, in Solenodon cubanus I have many samples for to do, etc, I did stomag content in Rattus rattus and Mus musculus an it was very complicated. Now I am thinking to find a student to do something with gecko excrement (Hemidactylus mabouia and H. angulatus two invasive in Cuba).
the problems with the stomag content is that the animal must be capture in the end of feeding hour to a best result. Nocturnal animal is a challenge too.
I would also like a copy please. I've been using gravity based stomach flushing for a long time and an improved method would be very welcome.
Hi Andre, if you don't mind, please send the MS to me. Interesting. Also, would like to add, that focal observations also may add valuable information about the diet.
André, por favor, inclúyeme en el listado de envíos ([email protected]).
Tratamos de usar el "flushing" y fue desastroso y cruel.
Gracias de antemano,
Herman
Buenos dias, Herman! Si, claro. Gracias por su interés y buena suerte en su trabajo.
André.
Neil, Daniel and Eduard, thank you for your interest.
Please, you can find my article in my profile RG, entitled:
"Gastric suction as an alternative method in studies of lizard diets: tests in two species of Enyalius (Squamata)".
Regards,
André.
Eduard, yes, the animal focal (observations) is a great method to complement the data about the diet of species!
I used this method in other article about foraging mode in a species of lizard, which I studied during my dissertation (Master).
You can find my article in my profile RG, entitled:
"Activity, foraging mode and microhabitat use of Enyalius perditus (Squamata) in a disturbed Atlantic rainforest in southeastern Brazil."
It is in my RG profile.
Feel free to download also.
Good luck in your study.
André.
Colleagues, I also recommend the work:
"Chapter: Diet: A Handbook of Techniques" (Luca Luiselli & Giovanni Amori).
There are other interesting methods to see!
Regards,
André.
I would like to share a method (gastric suction) which avoids, in most cases, or minimizes the death of animals in diet studies.
Article Gastric suction as an alternative method in studies of lizar...
Hello André
We tested your method of Gastric suction, in Liolaemus lizards in Chile. In general, the method work well, the unique problem was that the lizards open the mouth. We see, that is most easy (in lioalemus) make the suction inmediately with the capture. We written a short note, but was reject for low N and being a short study.
Best wishes
Hi, Gabriel. Very nice news!
Por suposto en lo campo es mejor realizar el método.
It is another advantage this method.
To open the mouth is better you use a tweezers, but with caution. Ok?
If you need some help to publish, let me know about.
I can see the manuscript for you.
Saludos.
André.
And yes, usually on the first try is when you get better results (when you already have a good practice or training with the method).
Thank you for the feedback.
Getting the mouth open and getting the device in and out of the animal are the tricky bits that risk injury to the animals. When I have tried to force mouths open teeth sometimes break. I found that using a wooden stick with a hole drilled through it that is wide enough for the device to fit through can make it easier. When the lizard has jaws clamped on the stick it's easy to keep them there. I've heard that animal keepers who get gripped by lizards dab alcohol on the gums to make them release, which probably isn't as risky as forcing the mouth open. I also think that the diameter of the device needs to be chosen as that which minimises risk to the animal rather than yields maximum stomach contents. Has anybody tried doing this with anaesthetics?
"Care and essential practices
Plastic pincers are recommended so that the animal’s teeth are not damaged, and each time the syringe is used, it must be lubricated with the saline solution in order to ease its way down the animal’s stomach.
Introduce small amounts of saline solution gradually into the animal to avoid spontaneous defecation. The internal anatomy of the individual animal should first be studied so that the shape, size, and position of the stomach and all other potentially affected organs are known.
The esophageal and stomach mucosa is quite resistant and flexible. However, forcing those tissues by abruptly inserting the syringe or too quickly removing the plunger will probably cause perforations or lesions.
I have learned that the lizard will be more likely to close its mouth in direct proportion to the number of attempts to introduce the syringe. Therefore, with increasing experience, the researcher, after observing no contents in the syringe at the mid-way point, may be able to re-insert it very slowly to attempt another extraction. This will reduce manipulation time thereby lessening the animal’s discomfort."
"The gastric suction proved to be a quick and reliable procedure requiring only a few simple, low-cost materials. Even in the natural environment, after some practice, anyone is able to do it in 1–2 min, and often stomach contents are extracted in one attempt only. This keeps animal suffering low and spares the animals of risky anesthesia (e.g. a wrong dose may kill them) and the recuperation time after anesthesia. Therefore, I suggest the use of gastric suction as a less invasive method, preserving the lives of many lizards in ecological and behavioral research."
Hi, Daniel,
Initially I was thinking to use anesthetic also, but after learning all these issues with veterinary colleagues, I thought best give up the idea:
To control the anesthetic used, the time and the right dose in the animal and while maintaining ok vital signs (sometimes even to be intubated) is not a simple task (in addition, it is more expensive), since they have to revive it later and the animal will need a longer recuperation (if all goes well). In addition, without a response from the animal awake, we can injure it internally, thinking that "everything is ok" due just to the anesthetic effect.
Grateful for your question! It was very important and timely to clarify these important aspects of animal care.
Best regards.
André.
All these "Care and essential practices" are described in Barreto-Lima (2009), as well as the "Description of the gastric suction technique" in five steps.
Thank you for your interest.
André
What is your mail, I should send a copy of paper in Liolaemus not published. Maybe we can to do something.
Saludos
"Description of the gastric suction technique:
The materials used consisted of a 0.5 or 1 ml plastic syringe, cut and polished on the upper end for opening (with the caliber of 0.4–0.5mm), pincers, a thin brush with round plastic cable, and saline solution (NaCl 0.85%).
*The snout–vent length (SVL) ranged from 63 to 86 mm for E. perditus and from 60 to 83mm for E. bilineatus, obtained through a manual vernier caliper (0.1 mm accuracy).
* Important: Then, a 0.5 ml syringe was predominantly used for lizards up to about 80mm SVL, while the 1 ml syringe was used for individuals larger than 80 mm SVL.
Step 1
The lizards were held in one hand leaving the other free to open the animal’s mouth and carry out the procedure. In order to ensure the animal’s safety, it was necessary to put the lizard into a vertical position, holding it by its neck on either side of the skull (Figure 1A).
Step 2
While retained, the lizards tended to spontaneously open their mouths in an attempt to bite the intrusive object, thereby making the first extraction relatively simple. Otherwise the mouths were opened with the pincers (Figure 1B).
Step 3
A syringe dampened with the saline solution was carefully inserted through the mouth into the stomach pylorus or stomach. During the insertion of the syringe, one could feel the tip of the syringe pass beyond the esophagus to reach the stomach. Care was taken to avoid contact with the stomach mucosa. A small amount of solution (0.2– 0.3ml) was slowly introduced into the stomach (Figure 1C).
Step 4
The stomach material was sucked by softly retracting the syringe pump while the syringe was slowly withdrawn from the animal (Figure 1D). This way the contents of the syringe would not overflow or leak to the outside (Figure1E). In most cases, an animal’s stomach contents could be extracted in one or two attempts. Therefore, at most three attempts should be performed, because the greater the number of attempts, the greater the risks of harming the animal. The stomach con- tents were then directly fixed in 70% ethanol (Figure 1F).
Step 5
At the last suction, after the syringe was withdrawn, the round end of a thin plastic paint-brush (smaller diameter than the syringe) dampened with saline solution was delicately inserted into the stomach to determine whether the stomach was in the correct position, thereby confirming the absence of any blockage in the digestive tract and avoiding reversal of the digestive tube or compaction of the mucosa."
* Please, see the Figure 1 in: Barreto-Lima (2009).
Hi Andre, I thought you would like to join our page from the ASG (Amphibians Specialist Group) Communication and Education on FB, there are also other groups from ASG that might be useful to you:):) Desculpe plela demora em enviar o article. Espero que recebeu:) Abraços . Amphibian Communication & Education. https://www.facebook.com/groups/609268709207116/
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