Its actually still called "founder"...a pony is known as "foundering" when the pedal bone rotates and drops through the hoof causing all sorts of damage :(
We also no longer hose laminitic ponies. Affected ponies should be immediately moved to a deep bed where they can either lie down (if bad) or the shavings can help the pony take the weight off the affected areas. Laminitis is a killer so its important to move the pony from grass immediately and Bute and ACP should be given by the vet. Its also important to get an accurate assessment of what damage has occured with the pedal bone rotation before anything else is done with the pony. Your farrier is sometimes the best bet to assess the pony and fit special support shoes if needed. Ad lib haylage (low sugar high fibre one - the vet will advise amounts if Ad lib is not allowed) can be given with Dengie Hi-Fi lite.
Laminitis IS a killer - it is a deadly disease. Prevention is found in:
Watching ponies weight - fat ponies most at risk
Watching the grass intake - sunny days following rain are the worst as the sugars come out in the grass
Short grass is sometimes worse than long grass because of the new shoots coming though - but long grass is also bad because of the amount the horse can eat...therefore laminitic ponies should be kept in starvation paddocks - but not starved - fed hay.
First signs - weigh shifting, pottering, backward stance, lameness...
Good site:
http://www.laminitis.orgYou can also give a supplement to help - Founderguard is a good one I believe - and a lack of Magnesium is also linked to laminitis.
Good luck.