Hello Rainer,
Dresdner schrieb:
Can it be only your birds is susceptible?
Not at all.
As an example, British birdkeepers have repeatedly reported that the following species are vulnerable to coccidiosis.
Gruenfink = Greenfinch = Carduelis chloris
Distelfink = Goldfinch = Carduelis carduelis
Birkenzeisig = Redpoll = Carduelis flammea cabaret
Buchfink = Chaffinch = Fringilla coelebs coelebs
I have asked at the Carduelid Forum here this same question.
DannyK was kind enough to give me the following very informative reply:
<< The young birds of Greenfinches and Chaffinches must be treated against coccidiosis before the moult begins, otherwise many of these young birds will die. Goldfinches and Redpolls do not need medicines and moult out without any problems.>>
So this means that either German tap water may still have some coccidia and Trichomonas living in it OR neither German or British tap water contain protozoans and the coccidia that the young Greenfinches have consumed do not come from tap water at all. I was going to visit the link you gave me in order to see what they had to say about protozoans in Dresden tap water but the page would not open. If you could email them regarding this, it could gives us more information.
Dresdner schrieb:
In the forum for African finches I found nothing regarding water problems.
In my experience, the Schlegel Twinspots are really vulnerable. I have had many die due to Trichomonas and or Coccidia. For every cock that died, about 3 hens died for me. I must add that I have given them access to 24 hour bathing with an automatic water system that I built. Other African species did not become ill but the Schlegel adults became ill every 4 months or so. I diagnosed Trichomonas. They probably had coccidia as well.
Dresdner schrieb:
English drinking water will not be worse than German drinking water.
I doubt it. I have often heard that the quality of tap water in the UK is behind that of the European standard and it will be years before it will be of the required standard all over the UK. This would explain why British carduelid breeders report coccidiosis problems with their Goldfinches and Redpolls whereas DannyK says that you have no such problems with these 2 species in Germany.
Dresdner schrieb:
Our drinking water from the line is transferred mixed with chlorine (Cl).
The chlorine may not be enough to kill the parasitic protozoans that affect birds but not humans. Filters of higher quality may be required to do this. It may also possible that if the water pipes themselves are old, they may have permanent protozoan colonies in them. The problem is that writing to the British Water Authority is of no real help because they are likely to say that they are using the most advanced filters and methods of purification and laying new pipes all the time. As far as I know there is no independent British agency that analyzes British tap water that can give me an analysis that I can trust. The only way I can do it is to pay for laboratory analysis myself over a period of weeks in order to get a good idea of the protozoans that are present in my local tap water.
William