I have also heard tell of 'acute oak decline' - am I right in thinking this is this a general description of the result of 'sudden oak death' and other tree diseases, or is it another disease itself.
Here you go, there are other pages on the site on Oak problems
http://www.forestry.gov.uk/website/forestresearch.nsf/ByUnique/INFD-7B3BZU
Chronic Oak Decline/Dieback - is a slower form of dieback over decades. Look for stag headed Oaks, that look healthy on the lower 60-70 % They tend to stay at this sort of state as they recover. The deadwood is very strong and hardly ever fails.
Acute Oak decline - is a faster form of decline over a couple of years, and is a recent problem, more aggressive than above, more problems and less chance of recovery.
Both the above are a combination of things the Oak doesn't like such as extremes of weather, attack from disease(possibly a Bacterium which is unknown)/insects, a change in site conditions.
Sudden Oak Death - gets confused with Acute Oak Decline as they both cause Bleeding on the stems, and is caused by Phytophthora ramorum a Fungle disease, which seems to spread from Infected Larch. I heard some Oaks in this country have possibly had it but the latest problem is the massive upsurge in infected Larch and possible spread.