Anthrax - may possibly be in the hores hair, but will be at very low levels, and shouln't be a problem.
Many moons ago BR had a problem when refurbishing the station buildings at Kings Cross station. White powder was found in the roof space - it was from the platerwork up there, and was tested, and found not to be a danger to workers, although it contained very low levels of 'inert' anthrax spores
This website may be of use;-
http://www.bricksandbras....uk/diy/diy_dangers.php, and it says;-
"Anthrax in Plaster
Plaster usually contains horsehair and, before controls were introduced in 1895, could contain anthrax spores. Although there are no recorded cases of infections from this source, when removing plaster you should take reasonable precautions.
English Heritage recommend that you should:
■cover all cuts, abrasions and other wounds with waterproof dressings to prevent infection
■ keep hands and fingernails clean and avoid hand-to-mouth contact during work
■ wear protective clothing (such as disposable gloves, overalls, eye protection, dust masks) appropriate to the task in hand. Dust masks should provide protection against infectious agents (FFP3 type, European Standard EN 149).
■not eat or drink in work areas and wash hands thoroughly before handling food
■ keep first aid kits well-maintained and to hand, and ensure they contain waterproof dressings
■ if removing old plaster, ensure that it is disposed of in accordance with local and statutory national controls, and that the generation of dust is minimised (e.g. by vacuum cleaning using a high-efficiency filter instead of dry-brush cleaning).
■ keep surrounding areas clean and dust-free
■ ensure that personal are informed of the risk and risk management strategy.
"