By: Dr.Henk de Weerd

Adeno (Circo) Coli infections young pigeons. (Young bird disease).

The adenovirus infections are described for a number of bird species. The pathogenesis ( the extent of causing the disease) of the viruses is most of the times low and often their precise role in the clinical picture is not clear. Most of the adeno viruses are considered to be complications  caused by other causative agents. However,  one can see a few of the adenoviruses as “exceptions” which are highly and primarily pathogenic ( unhealthy) as there are for example EDS, a virus disease that is responsible for a less laying by chickens and  the “bronchitis virus” we can see in quails. The same we see  with the H.E. and the adenoviruses in pigeons.  These adenoviruses in pigeons are responsible for 2 different  clinical pictures (syndromes) which both can cause serious damage to a pigeon population.

A frequent problem with the disease was the adenovirus type 1. We know all about these problems for already over 25 years. A number of the young bird stock is not answering anymore and start to vomit and becomes  sick. In the meantime they produce bright green watery stools and  are losing, sometimes visibly,  weight. From time to time the pigeon has trouble with digesting the drunken water and the crop       is still full with it.  They drink a few. The past showed a higher mortality rate than nowadays. The disease is spreading like wildfire (high rate of mortality) and from my point of view this clinical picture of the adeno (circo)-coli syndrome is especially an E-coli problem. Of course, one can find during a detailed check-up also other pathogens but E-Coli is by far the most important agent and this one responds in general positive after a treatment with antibiotics. So the problem is most of the times, with the right remedy well in hand  what means that the virus component (adeno type 1) in the past and the present circo virus (Dr.J.P.Duchatel) are of minor importance in this specific case. One assume that the circovirus can be an impediment for the infected pigeons  to build-up a natural immunity.

For a long time the part of the virus has not been clear. Almost all young pigeons are carrier but this fact , fortunately, not always leads to problems. Nowadays we see many problems with this adeno (circo)-coli syndrome all over globe, but at the same time the disease has become the last 5 years much less aggressive and much better to treat. One can do almost nothing preventive. Most of the times the disease starts in Belgium, mostly in May, in The Netherlands in June and in Germany even later. This has to do with the preparations (training tosses) for the young bird racing season. Also in the P.R. China and the U.S.A. we often see this problem. From the beginning it all started in Belgium.

The E-coli bacteria are generally speaking a part of the normal intestinal flora in human and animal so also the pigeon. In fact  it is common practice to prove  the presence of coli bacteria in the stool of pigeons. Sometimes the coli bacteria becomes pathogenic  and will cause problems which we have to treat. One did preventive vaccinations with the chicken adenovirus EDS. Following the manufacturer and the University of Gent the vaccine can’t be used for pigeons because it has a different antigenic (protein) structure. One of the results of the scientific research by Dr.Duchatel is that a possible vaccination with a circovirus vaccine (unfortunately not yet in the market) can bring the solution for this problem. We’ll have to wait and see. As often happens we don’t hear any longer about all kind of by-products such as colostrum.

Next time we talk about the way that the mortal adeno type II virus disease presented itself for the first time in 1991.

Translation: Henk de Brueijs