Answer:
"A wolf in sheep's clothing" refers to a situation where something that in first glance seems to be good or helpful, ends being bad.
Dutch disease refers to the pernicious effects caused by a significant increase in a country's foreign exchange earnings.
For example, suppose that there is good news like the finding of a lot of a given resource (like gold). Now, if the country's economy depends largely on the trade of gold, the news that a large reserve of gold has been found will likely decrease the price of gold, affecting in this way the economics of that country.
Then, something that at first glance looked nice (finding large quantities of the resource) ended being harmful to the country's economics.
This why there is a parallelism between the Dutch disease and the phrase "a wolf in sheep's clothing"