The euro hit a 22-month dollar low on growing evidence of an economic slowdown and as an EU summit failed to reassure investors over Greece's future in the euro zone.
The euro fell to $1.2516, against the dollar, hitting a low point last seen in July 2010.
It later stood at $1.2544, compared with $1.2582 in New York late Wednesday.
EU leaders reiterate support for Greece
At the end of the informal summit, EU leaders reiterated that they supported Greece's continued euro membership as long as it honours its commitments to fiscal consolidation and structural reforms.
The Taoiseach Mr Kenny has said that the text of the fiscal treaty will not be changed and that the treaty as it stands will be what Irish voters decide on on May 31st.
Mr Kenny said any growth agenda potentially agreed at the behest of the French president Francois Hollande would be separate to the text of the fiscal treaty.
Mr Kenny described the meeting as positive and said there was momentum on a range of ideas which would culminate in a number of decisions be taken at the next formal summit at the end of June.
These involved the development of so-called project bonds as well as fresh funding for the European Investment Bank.
The Taoiseach said he addressed EU leaders on the referendum campaign and on the initiatives he said had been taken to inform voters of the detail of the treaty.
He said there was strong support in some quarters to having the permanent EU bailout fund, the ESM, utilised in order to recapitalise banks, but he declined to say whether the German Chancellor would support or rule out such an idea.
He also said there was both support and opposition to the idea of commonly issued eurobonds.
The Taoiseach also said he'd held a meeting before the summit with Antonis Samaras, the leader of the Greek centre-right New Democracy Party, in which, he said, Mr Samaras had reported on a new coalition of centre right interests in advance of next month's elections and which would "honour their [bailout] commitments if elected."