The Source of Emerald Tree Boa Vomiting

 

 

KERRY SWAN

El Lagarto Farm

 

TOM WEIDNER

Habitat Systems

 

First of all, before we begin, let’s change the term: Emerald Regurgitation Syndrome to: Emerald Vomiting Disease. The term “regurgitation” is usually reserved for conditions in which the food comes back up before ever reaching the stomach, such as when adult animals store food in a crop or esophagus for later regurgitation to feed their young or when an animal develops a paralysis of the esophagus and food becomes impacted and further attempts at ingestion just come back up.

 

Emerald Vomiting Disease

 

Before this discussion begins, please recognize that this paper is not a true scientific study, nor is it claimed to be a documented research project (although much of the data we describe herein is directly taken from legitimate studies and projects). The authors’ intentions are to express educated opinions as to why, in some cases, vomiting occurs in emerald tree boas, although we have hard evidence that tells us to expect that research verifying our observations will soon surface! Remember where you heard it first!

 

Somewhere between a life of existence in the tropical rainforest, and the cage at your home, an emerald tree boa becomes a changed animal. It has been argued, that an emerald tree boa in the wild, will limit itself to small, head-sized meals on a limited schedule, to keep itself from throwing up - this is not reasonable, obviously. Nor is it arguable that an emerald tree boa survives by a continual pattern of eating and vomiting on a regular basis; captive specimens exhibiting this pattern are destined to die or at best stay barely alive.

 

So why are some imported emerald tree boas subject to this phenomenon after importation? The pattern has been clear for years to those who have kept them. Some never vomit regardless of what size of meal you feed them, some

vomit the day they arrive and continue doing so. Some vomit when meals are presented too often and are "too large". The most common pattern seems to be that an emerald arrives in the U.S. and within 6-8 weeks after set-up, the emerald has become chronic, vomiting within 24 to 48 hours after consuming a meal. Some of the causes may be among the following:

 

Protozoans are common and numerous in S.A wild caught reptiles, and can in themselves be a sole factor in vomiting of many S.A. imported species. (Trichamonas are extremely common). Other factors, such as too high of a temperature, stress, may also be factors that influence vomiting, but these are neither common nor as consistent as the causative agent in emerald tree boas that we have identified.

 

Enter the middlemen in the countries of export: the "trapper" (as they are referred to in Guyana) and the exporter. Exporters in Suriname and Guyana may approach an outer village chief, and ask for emeralds and other animals to be collected for him. Or, trappers-which are really just traveling collectors-may collect animals themselves. or stop by a village and see what they have for sale. This may include bags of snakes, tropical birds (still exported in mass to Spain and other countries) and mammals. In Guyana, these trappers will often go from exporter to exporter, like a door-to-door salesman to sell these animals. At other times, an exporter may need animals, like emerald tree boas, and barter for them from an another exporter. This includes exporters all the way to Suriname, and surrounding countries. Nizam Esahack, of the Guyana Pet and Aquarium Co., told one of the authors during his Guyana visit, that the idea of locality specific emerald tree boas is absurd; he has gotten them from as far away as French Guiana and they often trade back and forth to Suriname as needed! Apparently, the emerald tree boas that arrive in the U.S. at times are representative of the whole northern area of South America!

 

This brings up the true culprit of emerald vomiting: the tropical bird.

 

Tropical birds are routinely found to be infected with the organism Chlamydophila psittaci causing a disease known as “Psittacosis”.

 

What is Psittacosis?

 

Psittacosis is a disease, as mentioned, that frequents wild birds in the tropics. It is described by Dorlan's Medical Dictionary as, "a disease caused by a strain of Chlamydophila psittaci, first observed in parrots but later discovered to exist in other birds and domestic fowl in psittacine birds, it is characterized by respiratory and systematic infection."

 

In Guyana, exporting facilities are still housing mass amounts of parrots and macaws.  Nothing is done to prevent or detect Psittacosis in birds, and airborne or insect transmission of Chlamydophila to neighboring reptile cages is likely. Assuming that Chlamydophila can adversely affect reptiles. We are convinced that it does.

 

Chlamydophila is showing up in the stomach walls of emerald tree boas. In all necropsied emerald tree boas that were chronic, (vomiting after nearly every meal), Chlamydophila is present as anintracellular organism (shown in electron micrograms). HCl secreting cells are markedly absent proportionally to Chlamydophila infected cells. We expect data to appear soon showing numbers (a considerable amount that verifies these statements), but to this day, only Chlamydophila has been seen in this role, with no other findings whatsoever that would indicate a cause for vomiting.

 

If an emerald tree boa has no HCl secreting cells, it is incapable of initial breakdown of the food mass. Biology 101 tells us that true digestion occurs mostly in the small intestine of a vertebrate animal, and that the purpose of the stomach is to reduce the whole mass of food into a digestible "slush". If this is not possible at all, the unaffected rat, mouse or bird cannot physically continue down the alimentary canal, and is thus vomited up. In the case of partial HCl secretion by the stomach, soft tissue can be broken down to a liquid mass, but bones are not. This accounts for an emerald tree boa passing stools with bones in them, an initial warning sign that something is wrong with the snake's stomach processes.

 

We have suspected Chlamydophila as a cause for this disease for many years, and although we have seen documentation pointing to the direct relationship between vomiting, decrease in acid-producing gastric cells, and Chlamydophila infected gastric tissue, there are still some unanswered questions.

 

DIAGNOSIS

 

1.        Vomiting. (obviously)

 

2.        Loss of weight. (May not be vomiting on a regular basis)

 

3.        Bones in stool.

 

Soak stool in water and shake contents to check for bones. (Note: even if fed on pinky rats you will still find bones in the stool)

 

TREATMENT

 

The drug of choice for gastric Chlamydophila infection in reptiles is Doxycycline. This drug has been tested in 3 separate collections of emerald tree boasthat were imported from Suriname and Guyana in the past 3 years, and include over 40 chronic vomiters that exhibit the typical pattern for this disease.

 

The apparent successful dose that we have used for gastric Chlamydophilal infection in emerald tree boas is 25mg/kg orally, daily for ten days. Unfortunately, it appears that once Chlamydophila is eliminated from the digestive system, no new growth of HCl producing cells occurs. If treated early, an emerald tree boa can recover and feed as any other boid, since Chlamydophila has been stopped before it can "ruin” the entire stomach wall. We have seen that the prognosis for an infected emerald tree boa after treatment can be 100% recovery, or no recovery at all, i.e. a continued pattern of vomiting as before the treatment. Also is has been observed here that emeralds that just plain refuse to eat emaciate much slower over time than Chlamydophila infected vomiters.

 

One word of warning: Our results have shown that for emerald tree boas, Doxycycline is fatal in excessive doses.

 

UNANSWERED QUESTIONS

 

Several questions have arisen since the connection between Chlamydophila and vomiting in emerald tree boas has been found.

Why doesn't this affect other snakes, or does it?

 

Amazon Tree Boas are often kept with emerald tree boas in exporting countries, and are exposed to all the same pathogens, yet we have worked with hundreds of amazon tree boas , and rarely seen vomiting in these snakes. Yet vomiting in redtail boas and anacondas is nearly identical in the pattern seen for emerald tree boas - is it the same infecting organism?

 

Why doesn't the emerald tree boa’s stomach produce new "replacement" HCl cells after Chlamydophila has been eliminated?

 

It appears that once they are destroyed by Chlamydophila, these cells do not reappear, whatever cells are left are what the snake is destined to have to use.

 

How can you tell if your newly imported emerald tree boa is infected?

 

You can't. The burden now lies on the exporter to keep his animals separate from birds, and not buy emerald tree boas from bird collectors/keepers. There are Guyanan exporters with enough biological education to understand this problem; one that we know of collects her emeralds personally, does not keep birds in her facility or trade with other exporters. Of 45 imported emeralds obtained from her, not a single incidence of vomiting has occurred in two years of maintaining these animals. An infected emerald tree boa sitting in an importer or exporter's facility does two main things: it infects other emeralds by bodily excrement or insect carried transmission, and it cultures an increasing amount of Chlamydophila in it’s stomach, thus permanently eliminating it’s own acid producing cells.

 

IN CONCLUSION

 

We offer no documented scientific data to back up our opinions on this matter (as of yet..).We do believe very strongly from what we know that is going on in the research community, that hard documented, heavily funded evidence will appear soon...you can bet on it. With the many different types of literature and web pages that are circulating around the herpetological community, we wanted to share our findings as well. We have no more to offer than what is stated here.

 

Time will verify or void our findings!

 

Note: Chlamydia psittaci was recently reclassified as Chlamydophia psittaci.

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