For the second year in a row only one English team has reached the quarter-finals, while in 2013-14 no Premier League side made the last eight.
Spanish teams have won the trophy for the last three years, with Real Madrid twice beating city rivals Atletico in the final.
But Ferguson, who won the Champions League twice with Manchester United, says there's no need for English teams to stress over the current situation.
Ferguson told ESPN FC: "I think success is cyclical. If you think about the '90s, it was AC Milan. In the '70s, Ajax; and Bayern Munich in the '80s; Liverpool, in the '90s; Italy, AC Milan; then England had a great spell with three teams about six years ago all in the semi-final. We (United) were in three finals in four years.
"(Now) the domain is in Spain. There's no question about that. The same question could be asked about the German teams, why are Bayern Munich not winning the Champions League? Why are the Italians not winning it? Why are the French not winning it?
"But that will change, that can change. (Cristiano) Ronaldo will get older, (Lionel) Messi will get older. Can they replace these players?"
The ex-United boss also believes players today are not sufficiently prepared to become managers.
Read the full article on eurosport.co.uk: Spain's dominance in Europe will end as Ronaldo and Messi get older - Ferguson