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just thought some members would be interested in this
This "disease" which has become the scourge of Young Bird Derbies throughout the world is thought by many to have as its cause the infection by Adenovirus which then "opens the door" to infection by bacteria, most notably Escherichia coli. It is then thought that E. coli causes the symptoms such as initially a lack of appetite and later to vomiting and in general "shutting down the gut".
Neither feed nor water can pass along the gastro-intestinal tract. The bird may be seen sitting there with its crop full of water which is the reason Dr David Marx calls this disease "stagnant fluid in crop". The affected bird will try to vomit although its crop may be empty. The attempt to vomit must be the result of severe nausea.
The mucoid droppings are typical and are seen as one checks the perches early in the morning for vomited feed. Compare them to normal ones.
Here is a bird who closes its eyes as much as it dares to in order to conserve fluid. Producing fluid droppings without being able to get water from the crop into the intestinal tract leads inevitably to dehydration.
Being unable to absorb nutrients through the gastrointestinal tract leads to a shortage of energy which this bird tries to retain by fluffing its feathers for increased insulation. But all these measures by the bird will prove to be in vain. Any available carbohydrates in the form of glycogen, then fat, and finally muscle tissue are burned for providing the energy to stay warm.
Death will provide relief for this bird which has struggled in vain. Almost no breast muscle is left and life of this completely emaciated pigeon has come to an end prematurely.
I regret that I had to observe the above sequence of events many times and have become very Sad because of it. I wish I could prevent this from happening and am looking for the cause like many others.
One point of view is that Adenovirus itself does not seem to cause disease in pigeons except that it allows other, normal bacterial inhabitants of the intestinal tract to invade the bird's body and cause disease.
• But why would this dreaded "Young Bird Sickness (YBS)" strike most often when young birds of different lofts are mixed and put into one loft as it occurs in one loft young bird derbies?
o And why are some birds affected when other birds seem to stay healthy?
o Why are birds from some lofts more affected than birds from other lofts?
The answer must lie in the immune system which is rather immature in the young pigeon. Antibodies against various microbes with which the breeding pigeon was confronted are deposited in the egg yolk and used by the developing youngster. Antibodies also pass via the crop milk to the young pigeon after it has hatched , similar to the way antibodies in colostrum are transferred to new-born mammals.
Some parallels to mammals can be drawn:
• There is a limited and short time period during which the antibodies in the crop milk escape digestion and can be taken up directly by the circulation. Feeding crop milk after this time period has elapsed will not transfer any immunity to the bird because the antibodies present in the crop milk are digested by the now older pigeon.
• The adult animal can only develop resistance to the micro-organisms with which it was confronted at some time and against which it had to develop immunity by manufacturing antibodies. The adult pigeon cannot put antibodies into the crop milk which it does not have.
• Keeping animals free of many germs through either constant disinfection or the administration of antibiotics will lower their immune status and also lower the amount of antibodies they can put into the crop milk.
• Less antibodies in the crop milk translates into a youngster whose immune status is compromised.
Lack of immunity to the various microbes from different lofts appears to be the cause of young bird disease. On one extreme, germ-free animals are much more susceptible to disease than their conventional counterparts. Organisms such as Bacillus subtilis and Micrococcus luteus are harmless to conventional animals but are harmful to the germ-free variety. It would be difficult to infect normal animals with Vibrio cholerae and Shigella dysenteriae but these bacteria can infect germ-free animals readily. Germ-free or gnotobiotic animals require a diet supplying additional nutrients such as vitamin K and some vitamins of the B complex. These vitamins are normally synthesized by various micro-organisms in the intestinal tract of healthy pigeons. It can therefore be concluded that the conventional animal derives considerable benefits from its gastro-intestinal flora of micro-organisms.
At the other extreme are pigeons that are raised without antibiotics in a loft with dried droppings or even dosed with microbes in their Drinking water. The hens, being constantly exposed to a multitude of microbes, are therefore forced to develop immunity to these microbes. Some of the resultant antibodies are included in the egg yolk and give the just hatched youngster passive immunity to the microbes it will encounter in this loft. There will be a constant exposure of this youngster to the microbial inhabitants in the loft because the adults eat the occasional droppings in order to benefit from the vitamins contained therein, and the young bird will begin to develop its own antibodies to these microbes resulting in the development of active immunity.
Studies suggest that this aquired immunity is active not only against the micro-organisms which caused its development. Some activity is also present against unrelated microbes such as viruses. There is indeed experimental evidence that an encounter with various bacteria may lead to increased immunity in general(British Medical Journal).
Each youngster arriving at a one loft derby represents a bag filled with the various microbes present in the loft of its origin. We now mix all those hundreds of bags and their contents resulting in a super micro-flora. Although each youngster may be immune to the micro-flora of its loft of origin, it is now suddenly confronted with micro-organisms from all those other lofts. It may be overwhelmed by these microbes, especially if its own immune status was compromised by not having been exposed to many microbes where it was born and raised. With a healthy immune system, however, there will be some immunity to these new micro-organisms even before the synthesis of specific antibodies against them.
Dr. Ludger Kamphausen ("Die Brieftaube", 22.Juni 2002) sees YBS as a multi-factorial disease, meaning that many different microbes collectively cause this trouble. He implicates Trichomonas, Hexamita, Adenovirus, Circovirus, Herpes virus , various coliform bacteria and many others.
I do not think that it matters what name we attach to the virus(es) which can infect immunologically weak youngsters leading to YBS. Whatever its name, this virus appears to depress the immature immune system of the young pigeon further and it is now vulnerable to attack by other micro-organisms. This young bird may have had some immunity to the microbes it encountered in the loft of its origin, first passive immunity through the antibodies in the yolk and later active immunity due to actual challenges by the microbes in question. Should this acquired active immunity, however, be limited by having been raised in either an always disinfected loft or through the periodic administration of antibiotics to the breeding pigeons, the challenge by the multitude of microbes this bird encounters in, e.g., a derby loft may overwhelm it resulting in the symptoms of "young bird disease". One may instinctively reach for the readily available antibiotic and try to "cure".
Doxycycline appeared to be effective in many cases at the Alberta Classic Derby of 2001 but needed to be combined with Ridzol S in 2002 again to appear to be effective. BMD (bacitracin methylene disalicylate) also appeared to be effective for some cases in 2002 but any and all of these drugs fail because they are ineffective against the virus who could infect the bird in question due to his weak immune system which as a consequence of this infection will now be weakened further. What actually happened at the Alberta Classic in the years past was that the YBS went through the birds and abated entirely by itself in the middle of July. Any drug or combination of drugs in use at that time appeared to be very effective but proved worthless the following year.
This "disease" which has become the scourge of Young Bird Derbies throughout the world is thought by many to have as its cause the infection by Adenovirus which then "opens the door" to infection by bacteria, most notably Escherichia coli. It is then thought that E. coli causes the symptoms such as initially a lack of appetite and later to vomiting and in general "shutting down the gut".
Neither feed nor water can pass along the gastro-intestinal tract. The bird may be seen sitting there with its crop full of water which is the reason Dr David Marx calls this disease "stagnant fluid in crop". The affected bird will try to vomit although its crop may be empty. The attempt to vomit must be the result of severe nausea.
The mucoid droppings are typical and are seen as one checks the perches early in the morning for vomited feed. Compare them to normal ones.
Here is a bird who closes its eyes as much as it dares to in order to conserve fluid. Producing fluid droppings without being able to get water from the crop into the intestinal tract leads inevitably to dehydration.
Being unable to absorb nutrients through the gastrointestinal tract leads to a shortage of energy which this bird tries to retain by fluffing its feathers for increased insulation. But all these measures by the bird will prove to be in vain. Any available carbohydrates in the form of glycogen, then fat, and finally muscle tissue are burned for providing the energy to stay warm.
Death will provide relief for this bird which has struggled in vain. Almost no breast muscle is left and life of this completely emaciated pigeon has come to an end prematurely.
I regret that I had to observe the above sequence of events many times and have become very Sad because of it. I wish I could prevent this from happening and am looking for the cause like many others.
One point of view is that Adenovirus itself does not seem to cause disease in pigeons except that it allows other, normal bacterial inhabitants of the intestinal tract to invade the bird's body and cause disease.
• But why would this dreaded "Young Bird Sickness (YBS)" strike most often when young birds of different lofts are mixed and put into one loft as it occurs in one loft young bird derbies?
o And why are some birds affected when other birds seem to stay healthy?
o Why are birds from some lofts more affected than birds from other lofts?
The answer must lie in the immune system which is rather immature in the young pigeon. Antibodies against various microbes with which the breeding pigeon was confronted are deposited in the egg yolk and used by the developing youngster. Antibodies also pass via the crop milk to the young pigeon after it has hatched , similar to the way antibodies in colostrum are transferred to new-born mammals.
Some parallels to mammals can be drawn:
• There is a limited and short time period during which the antibodies in the crop milk escape digestion and can be taken up directly by the circulation. Feeding crop milk after this time period has elapsed will not transfer any immunity to the bird because the antibodies present in the crop milk are digested by the now older pigeon.
• The adult animal can only develop resistance to the micro-organisms with which it was confronted at some time and against which it had to develop immunity by manufacturing antibodies. The adult pigeon cannot put antibodies into the crop milk which it does not have.
• Keeping animals free of many germs through either constant disinfection or the administration of antibiotics will lower their immune status and also lower the amount of antibodies they can put into the crop milk.
• Less antibodies in the crop milk translates into a youngster whose immune status is compromised.
Lack of immunity to the various microbes from different lofts appears to be the cause of young bird disease. On one extreme, germ-free animals are much more susceptible to disease than their conventional counterparts. Organisms such as Bacillus subtilis and Micrococcus luteus are harmless to conventional animals but are harmful to the germ-free variety. It would be difficult to infect normal animals with Vibrio cholerae and Shigella dysenteriae but these bacteria can infect germ-free animals readily. Germ-free or gnotobiotic animals require a diet supplying additional nutrients such as vitamin K and some vitamins of the B complex. These vitamins are normally synthesized by various micro-organisms in the intestinal tract of healthy pigeons. It can therefore be concluded that the conventional animal derives considerable benefits from its gastro-intestinal flora of micro-organisms.
At the other extreme are pigeons that are raised without antibiotics in a loft with dried droppings or even dosed with microbes in their Drinking water. The hens, being constantly exposed to a multitude of microbes, are therefore forced to develop immunity to these microbes. Some of the resultant antibodies are included in the egg yolk and give the just hatched youngster passive immunity to the microbes it will encounter in this loft. There will be a constant exposure of this youngster to the microbial inhabitants in the loft because the adults eat the occasional droppings in order to benefit from the vitamins contained therein, and the young bird will begin to develop its own antibodies to these microbes resulting in the development of active immunity.
Studies suggest that this aquired immunity is active not only against the micro-organisms which caused its development. Some activity is also present against unrelated microbes such as viruses. There is indeed experimental evidence that an encounter with various bacteria may lead to increased immunity in general(British Medical Journal).
Each youngster arriving at a one loft derby represents a bag filled with the various microbes present in the loft of its origin. We now mix all those hundreds of bags and their contents resulting in a super micro-flora. Although each youngster may be immune to the micro-flora of its loft of origin, it is now suddenly confronted with micro-organisms from all those other lofts. It may be overwhelmed by these microbes, especially if its own immune status was compromised by not having been exposed to many microbes where it was born and raised. With a healthy immune system, however, there will be some immunity to these new micro-organisms even before the synthesis of specific antibodies against them.
Dr. Ludger Kamphausen ("Die Brieftaube", 22.Juni 2002) sees YBS as a multi-factorial disease, meaning that many different microbes collectively cause this trouble. He implicates Trichomonas, Hexamita, Adenovirus, Circovirus, Herpes virus , various coliform bacteria and many others.
I do not think that it matters what name we attach to the virus(es) which can infect immunologically weak youngsters leading to YBS. Whatever its name, this virus appears to depress the immature immune system of the young pigeon further and it is now vulnerable to attack by other micro-organisms. This young bird may have had some immunity to the microbes it encountered in the loft of its origin, first passive immunity through the antibodies in the yolk and later active immunity due to actual challenges by the microbes in question. Should this acquired active immunity, however, be limited by having been raised in either an always disinfected loft or through the periodic administration of antibiotics to the breeding pigeons, the challenge by the multitude of microbes this bird encounters in, e.g., a derby loft may overwhelm it resulting in the symptoms of "young bird disease". One may instinctively reach for the readily available antibiotic and try to "cure".
Doxycycline appeared to be effective in many cases at the Alberta Classic Derby of 2001 but needed to be combined with Ridzol S in 2002 again to appear to be effective. BMD (bacitracin methylene disalicylate) also appeared to be effective for some cases in 2002 but any and all of these drugs fail because they are ineffective against the virus who could infect the bird in question due to his weak immune system which as a consequence of this infection will now be weakened further. What actually happened at the Alberta Classic in the years past was that the YBS went through the birds and abated entirely by itself in the middle of July. Any drug or combination of drugs in use at that time appeared to be very effective but proved worthless the following year.
