Avian Intestinal Spirochaetosis more widespread
Avian intestinal spirochaetosis may be more
widespread than previously thought, and new calculations show that the potential
losses to the UK laying industry could be more than Â£4.1 million (6 million
euros) per year, assuming that 30% of laying flocks are
Avian Intestinal Spirochaetosis causes chronic soft to watery brown
droppings, a 10% drop in egg production and 8% increase in mortality over the
Recent research shows that Avian intestinal spirochaetosis is especially
common in free-range flocks where B. intermedia appears to dominate.
Caged flocks can be infected but B. pilosicoli appears to be more
Newly published research by three specialist poultry veterinarians records
just how widespread spirochaetosis may be, both in caged and free-range
In a small survey of six caged-hen flocks with depressed production, one
flock had pale eggs, thought to be associated with high avian pneumovirus
(ART/TRT) titres and only B. innocens was isolated. In the other 5
flocks, B. pilosicoli were cultured and only one of these flocks, with
the most severe performance drop, showed rising IB titres as well. It is
important to carry out a number of tests to obtain a correct diagnosis, as it
may involve more than one causal agent.
Treatment of laying hens is limited to two antibiotics in some EU countries,
because of the necessity for a zero withdrawal period in eggs. Both tiamulin and
chlortetracycline have been used separately and in combination to control these
spirochaete infections and tiamulin has been shown to be effective where
chlortetracycline resistance occurs.
report is available online.
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