FaunaClassifieds - View Single Post - Adenovirus

11-02-2006, 09:55 AM

Cheri,

I was going on the published information that is available to the public on this particular study. I found no published information on the animals that may have survived - and nothing to indicate that further studies or tests were being performed on those remaining animals.

I do appreciate the offer to forward emails concerning Susanne’s situation, but there is no need to unless they offer more details. What I would honestly like to review (if it is even available) is follow-up care and testing that was performed on these dragons and their father. We have studied Dan’s paper and conclusions. What is missing, for us at least, is the data to support it… How many EM tests were performed and on which dragons? At what time intervals were they performed? Where were the animals housed? How many animals housed per cage? Were the animals ever bred? If so, was it sibling-to-sibling? Father-to-offspring? How many clutches were produced? Eggs per clutch? Hatch rates and mortality? For us this information is relevant.
Since 2002 there have been no updates or additional papers produced by Dan.

I know of no studies or surveys that would indicate the % population that may be infected with adenovirus either, but by using the study above in a “what if” scenario the viral infection could very well be wide-spread, with occasional outbreaks of illness. Why would we suspect this to be so? There is evidence to support this theory based upon hatch rates and mortality rates alone of various breeders over the years.

In the book Bearded Dragons and Frilled Lizards, written by Andree Hauschild and Hubert Bosch (translated from German to English by John Hackworth in 2000) a summary of Husbandry Experiences of 12 small breeders/collectors of vitticeps (p.56,57) was reported. The dragons ages were 1-11, with 2 to 10 dragons per collection - totaling 47 dragons. (sex ratio of 17.30)
The average hatch rate of the 12 breeders was 79.9% - 3 of the 12 breeders experienced a 50% hatch rate and only 1 with 100% - which is on average 4 failed eggs out of every 20 laid.
In The Bearded Dragon Manual, written by Bob Mailloux and Phillie de Vosjoli it is stated that they estimate 15-25% of their eggs fail to hatch. An average of 20% failure.
The averages from Germany to the USA are almost identical - even with variances in husbandry - at 20% failure to hatch.

On page 30 in the Bearded Dragon Manual, the mortality rates of vitticeps are listed as 9-24% from various clutches.
The German publication does not list any mortality rates for the dragons charted. Based upon the similarity in hatch rates, lets assume the mortality rates are relatively close - possibly being a little better due to smaller size of the collections at 5-20%.

Keeping in mind that the information contained in these books was compiled in the 1990’s or earlier - Both of these scenarios are above the quoted 10% mortality rate that Dan states in his paper to be “suspect” of having the adenovirus.

Also in Dan’s paper regarding adenovirus he says “If two or more clutch mates are kept together and one is much smaller, suspicion should be high.” To keep this short, one statement, in one book attributes retarded growth to stress. Bearded Dragons and Frilled Lizards (p.30,31) “Naturally, it is important that all animals are approximately the same size otherwise problems will be unavoidable. This is illustrated by Sprenkel’s (1990) case in which stressed juveniles became retarded in their growth and then quickly became part of the diet of their siblings which were twice as large.”

Surely, these animals in Germany, in 1990 could have the adenovirus based on Dan’s statement. Or one could choose to apply Sprenkel’s observations and attribute retarded growth to stress. It could be adenovirus, it could be stress - or it could be the combination of the 2. These are only 2 of many contributing factors that could explain retarded growth. How about limited genetics, age/diet/productivity of the female parent, immune systems, coccidia levels, other pathogens, food preferences, temperature preferences, etc… There is also a theory on separating sexes at a very young age. All of these factors along with many others need to be considered. It is very easy (and we believe commonplace) to identify a specific factor and attribute blame without investigating the other possible factors.

We are not basing anything on what Bruce has posted himself or any of his quotes. All of our information has come from either documented scientific research, printed information or through our own experiences, conversations with various professionals and long-term breeders.

We simply did'nt mention the other cases that were in Australia or Illinois because they were respectively barbatus and henrylawsoni that were examined. I apologize, I should have been more clear in my statement… To the best of my knowledge, the first documented case of adenovirus in a vitticeps was by Dr. Jacobson in 1996.

I am happy that there is an opportunity for further study of the fecal samples being submitted. My hope is that those which test positive for adenovirus on an EM will go on to the PCR for further identification and classification. Even if studies are not being actively performed at this time - the data can still be processed and documented for future use. I understand that there are time & funding constraints and priorities to consider when it comes to a research project of this magnitude and I am not presuming that Dr. Jacobson and his team are even willing to do the studies.

I am not frustrated at the lack of available answers… but more so the un-asked questions, and the disregard of other available data/observations. I don’t mind receiving the response “I don’t know” but we believe the very next question should be “What can we do to find out?”

“Adenoviruses were first isolated from adenoids surgically removed from children in 1953 as part of a study to evaluate different tissues for growth of polio viruses by Rowe et al.” The information now available for the various types of human adenoviruses is invaluable. It has been 40+ years of gathering information - Information which has proven to be applicable to other species - if the medical/scientific connections can be made.
The problem is, there is no data to utilize - therefore no conclusions can be made.

Per Dr. Jacobson :
“It may turn out that there may be different strains of this virus in bearded dragons that cause different degrees of mortality. This eventually needs to be studied. Outcomes of lizards that are infected need to be studied. How long can a BD shed virus? The questions go on and on. Ultimately, transmission studies are needed to show that a specific virus can kill lizards.”

My last statement was in regard to the fact that there is much innuendo, supposition and guesswork on the adenovirus - but relatively no factual data that is available. If the experts’ responses are vague due to lack of research - how can we be specific?

The available “facts” can be spun to fit any scenario - as we did above.

Rob & Vickie

11-02-2006, 09:55 AM	#3
Dachiu	Cheri, I was going on the published information that is available to the public on this particular study. I found no published information on the animals that may have survived - and nothing to indicate that further studies or tests were being performed on those remaining animals. I do appreciate the offer to forward emails concerning Susanne’s situation, but there is no need to unless they offer more details. What I would honestly like to review (if it is even available) is follow-up care and testing that was performed on these dragons and their father. We have studied Dan’s paper and conclusions. What is missing, for us at least, is the data to support it… How many EM tests were performed and on which dragons? At what time intervals were they performed? Where were the animals housed? How many animals housed per cage? Were the animals ever bred? If so, was it sibling-to-sibling? Father-to-offspring? How many clutches were produced? Eggs per clutch? Hatch rates and mortality? For us this information is relevant. Since 2002 there have been no updates or additional papers produced by Dan. I know of no studies or surveys that would indicate the % population that may be infected with adenovirus either, but by using the study above in a “what if” scenario the viral infection could very well be wide-spread, with occasional outbreaks of illness. Why would we suspect this to be so? There is evidence to support this theory based upon hatch rates and mortality rates alone of various breeders over the years. In the book Bearded Dragons and Frilled Lizards, written by Andree Hauschild and Hubert Bosch (translated from German to English by John Hackworth in 2000) a summary of Husbandry Experiences of 12 small breeders/collectors of vitticeps (p.56,57) was reported. The dragons ages were 1-11, with 2 to 10 dragons per collection - totaling 47 dragons. (sex ratio of 17.30) The average hatch rate of the 12 breeders was 79.9% - 3 of the 12 breeders experienced a 50% hatch rate and only 1 with 100% - which is on average 4 failed eggs out of every 20 laid. In The Bearded Dragon Manual, written by Bob Mailloux and Phillie de Vosjoli it is stated that they estimate 15-25% of their eggs fail to hatch. An average of 20% failure. The averages from Germany to the USA are almost identical - even with variances in husbandry - at 20% failure to hatch. On page 30 in the Bearded Dragon Manual, the mortality rates of vitticeps are listed as 9-24% from various clutches. The German publication does not list any mortality rates for the dragons charted. Based upon the similarity in hatch rates, lets assume the mortality rates are relatively close - possibly being a little better due to smaller size of the collections at 5-20%. Keeping in mind that the information contained in these books was compiled in the 1990’s or earlier - Both of these scenarios are above the quoted 10% mortality rate that Dan states in his paper to be “suspect” of having the adenovirus. Also in Dan’s paper regarding adenovirus he says “If two or more clutch mates are kept together and one is much smaller, suspicion should be high.” To keep this short, one statement, in one book attributes retarded growth to stress. Bearded Dragons and Frilled Lizards (p.30,31) “Naturally, it is important that all animals are approximately the same size otherwise problems will be unavoidable. This is illustrated by Sprenkel’s (1990) case in which stressed juveniles became retarded in their growth and then quickly became part of the diet of their siblings which were twice as large.” Surely, these animals in Germany, in 1990 could have the adenovirus based on Dan’s statement. Or one could choose to apply Sprenkel’s observations and attribute retarded growth to stress. It could be adenovirus, it could be stress - or it could be the combination of the 2. These are only 2 of many contributing factors that could explain retarded growth. How about limited genetics, age/diet/productivity of the female parent, immune systems, coccidia levels, other pathogens, food preferences, temperature preferences, etc… There is also a theory on separating sexes at a very young age. All of these factors along with many others need to be considered. It is very easy (and we believe commonplace) to identify a specific factor and attribute blame without investigating the other possible factors. We are not basing anything on what Bruce has posted himself or any of his quotes. All of our information has come from either documented scientific research, printed information or through our own experiences, conversations with various professionals and long-term breeders. We simply did'nt mention the other cases that were in Australia or Illinois because they were respectively barbatus and henrylawsoni that were examined. I apologize, I should have been more clear in my statement… To the best of my knowledge, the first documented case of adenovirus in a vitticeps was by Dr. Jacobson in 1996. I am happy that there is an opportunity for further study of the fecal samples being submitted. My hope is that those which test positive for adenovirus on an EM will go on to the PCR for further identification and classification. Even if studies are not being actively performed at this time - the data can still be processed and documented for future use. I understand that there are time & funding constraints and priorities to consider when it comes to a research project of this magnitude and I am not presuming that Dr. Jacobson and his team are even willing to do the studies. I am not frustrated at the lack of available answers… but more so the un-asked questions, and the disregard of other available data/observations. I don’t mind receiving the response “I don’t know” but we believe the very next question should be “What can we do to find out?” “Adenoviruses were first isolated from adenoids surgically removed from children in 1953 as part of a study to evaluate different tissues for growth of polio viruses by Rowe et al.” The information now available for the various types of human adenoviruses is invaluable. It has been 40+ years of gathering information - Information which has proven to be applicable to other species - if the medical/scientific connections can be made. The problem is, there is no data to utilize - therefore no conclusions can be made. Per Dr. Jacobson : “It may turn out that there may be different strains of this virus in bearded dragons that cause different degrees of mortality. This eventually needs to be studied. Outcomes of lizards that are infected need to be studied. How long can a BD shed virus? The questions go on and on. Ultimately, transmission studies are needed to show that a specific virus can kill lizards.” My last statement was in regard to the fact that there is much innuendo, supposition and guesswork on the adenovirus - but relatively no factual data that is available. If the experts’ responses are vague due to lack of research - how can we be specific? The available “facts” can be spun to fit any scenario - as we did above. Rob & Vickie