Young Bird Sickness 2002
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.
mucoid droppings are typical and are seen as one checks the perches early in the morning for vomited feed. Compare them to
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.
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.
- 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?
- And why are some birds affected when other birds seem to stay healthy?
- Why are birds from some lofts more affected than birds from other lofts?
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 who 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.
The answer? Every attempt will be made not to use antibiotics.
We will try to improve the environmental conditions by:
- increasing the floor space to 32 feet per bird,
- opening up the front of 40 feet for better ventilation
- and providing a wire floor for the prevention of wet areas and mold. Its spores and toxins is undesirable in any loft.
It is our aim to decrease various stresses which would cause an increase in the release of cortisone, an adreno-cortical hormone with a powerful anti-inflammatory effect. (The suppression of inflammation removes one of the defenses an animal has against infectious disease. Please see Stress) The spread of infections via the drinking water will be controlled with various drinking water additives.
However, any measures taken at a derby loft are very limited. A bird with a weak immune system will succumb to the various microbes it encounters. It is obvious that the best and only prevention ultimately rests in increasing the immunity of the young birds before their arrival by not exposing their parents to antibiotics but rather by incorporating the use of probiotics as advocated in the following pages:
November 5, 2002:
Besides Adeno-, Herpes- and Circoviruses, Dr Soike found another kind of virus implicated as the basis of young bird sickness.
Other factors found are Trichomonas, Hexamita, Streptococci, Chlamydia and Escherichia coli which has been found in almost all of these infections. E. coli is
beneficial to the birds due to its synthesis of B vitamins which are taken up by young birds in the dried droppings they find and eat
It is perhaps not quite correct to refer to this organism as just "E. coli" because there is a multitude of different types from the completely benign
commensuals to the pathogenic ones which produce enterotoxins capable of stopping all transport along the gastro-intestinal tract and this symptom underlies all
cases of young bird sickness.
100 000.- Euro was earmarked by the German Racing Pigeon Organisation for further research into this problem which is
spreading like wild fire. In 2002, of 2 million young birds bred in Holland, 500 000 were infected. Nevertheless, Dr. van der Sluis warns against
exaggerated loft hygiene but instead advises to establish a "fecal corner" with pea straw as the bedding in every loft so that young birds can build a well
functioning immune system. He further advocates vaccinations against PMV and Salmonellosis in both old and young birds. Such vaccinations are best performed
2 to 3 weeks after weaning with a rest of 1 week between both vaccinations in young birds. The vaccination against Salmonellosis needs to be repeated in a couple of weeks.
Although vaccinating against an infection by Salmonella typhimurium is a means to keep this infection at bay, probiotics can do the same, experimental evidence of which exists and can be seen here.
Young Bird Sickness 2003
The symptoms pictured above were also seen in some birds during the summer of 2003. However, other symptoms were seen with a frequency increased from past years. A few birds suddenly died but many more just suddenly lost strength.
They were still full in flesh but could suddenly no longer walk or no longer fly. Some affected birds had both symptoms. Isolating them in a box for further observation revealed the usual symptoms of YBS with vomiting. Please notice the difference in the droppings
seen last year almost exclusively from some different ones seen at least in the initial stages of this year. Some can be likened to
rice water while others are almost
The first noticeable sign was the increased water consumption of the flock. Water just passed through in this variation of YBS and was no longer held in the crop. The increased water consumption accompanied by this diarrhea indicates the need of the bird for water and the lack of its ability to absorb it.
Details of the macabre events can be seen by following
Evidence of the usefulness of probiotics for preventing this ghastly disease can be seen by going here.
Update: (May 15, 2010)
|Update (March 4, 2004)
From the German periodical "Die Brieftaube" (2004, Nr. 7):
Interim Results about examinations regarding various viruses:
Translated from the German periodical "Die Brieftaube" (2004, Nr. 8):
The presence of various viruses in pigeons suffering from Young Bird Sickness was determined at the Universities of Leipzig and Gießen.
- Adenovirus and Polyomavirus PCR (polymerase chain reaction) tests of the livers were negative as were subsequent attempts at culturing.
- PCR tests regarding Herpesvirus was positive in 15% which could also be confirmed through cultures.
- The presence of Circovirus could be confirmed in 90% with the PCR test and 100% of all blood tests were positive as were all tests of the oil gland.
The trigger of young bird sickness is the Circovirus in connection with other disease-causing agents. At the FCI-level a related study is running that concentrates itself on how Circovirus is spread. From this comes the question of how one can most effectively fight the virus.
One should above all be certain of the diagnosis "young bird sickness". The following is useful only if "young bird sickness" is present,
i.e. the bird in question has the crop distended with water since the liquid is blocked from passing into the intestine and being absorbed.
I find it useful to prevent the birds from eating any feed vomited during the night. (Such feed is likely contaminated with the micro-organisms responsible for such vomiting.)
This can be accomplished by having the loft so dark at night that the birds cannot possibly
find any vomited feed. Then let the birds out into daylight (into an aviary, for example) before flooding the loft with light, check the loft now empty of birds and remove any vomited
grain. Should one find any vomitus one would need to also find the probable candidate(s) to be given individual treatment in the evening, a bird that is puffed up and not interested
in its surroundings, a bird that does not come to the feed trough or the one that does not come in for the evening meal. Feed the birds some pellets after calling them in the
morning and 30 gm grain per bird but only in the evening after their exercise and shortly before darkening the loft. Any bird not eager to fight for its place on the feed trough at
this time would be suspect of being ill.
A specific antibiotic can certainly be effective against the micro-organisms responsible for the
swelling of the intestines if it is not delivered too late and could still be absorbed by the bird. The prognosis used to be poor once the intestine was closed already due to spasm of
the smooth muscle in the intestinal wall since it allowed neither feed nor fluid (with any dissolved antibiotics) to pass. The bile would then flow in the opposite direction and could
be seen in the water with which the crop was filled. In spite of the crop being full of water the prognosis was that such bird would be condemned to die from dehydration.
There is now a method that allows us to re-open the intestines, i.e. to treat the symptoms of YBS, and this allows the young bird to recuperate.
- Empty the crop of most of the fluid.
- Into the crop infuse 30 ml strong fennel tea
- to which may be added the
proper amount of an antibiotic to which the offending micro-organism is sensitive but this is rarely necessary and usually not adviseable. All too often the affected young birds in the loft are infected by different secondary infective agents and 1 drug is not usually effective against all of them.
- Fennel tea relaxes the smooth muscle of the intestinal wall. This property makes it useful to
be employed against bloating and also
against colic in infants.
- Use fennel tea (made from 4 TBSP ground fennel per 4 litres water) as the drinking water of all birds in the loft for another week or as long as desired.
Removing stress from young birds affected by young bird disease will aid in their recovery.
- Repeat as often as necessary but especially after one sees some watery droppings.