I came across this in an article on livescience.com:
Anthrax has been used in bioterrorism and warfare since World War I, when Scandinavia deployed anthrax against the Imperial Russian Army. It was also used by the British army during World War II to weaken German livestock
Link to full article here
I can see how the WW2 claim may have arisen, as the UK did indeed have plans to do just that. However, the anthrax used against the Russian army one is new to me.
The remainder of the article seems factual, although it does seem either cut and paste heavy or possibly even auto-generated.
I have a geeky interest in propaganda and would love to find the original source of these claims.