Dortmund are in second place, a point behind leaders Bayern Munich, with three games left to play in the season. Bayern face Dortmund's bitter Ruhr rivals, Schalke 04, on Saturday.
"We only look at us. We worked our way into this flow against Wolfsburg and we tried to carry it through this week," Terzic told a press conference.
"We had a very intense training session yesterday. We will ease up today and pick it up again tomorrow. Then it's about showing what we are able to do."
"For us there is one common goal and we are happy that it is such a tight race, the tightest in years, and that it is not yet over."
While Dortmund have been the strongest team at home, having scored a staggering 18 goals in their last four home league games, they have struggled for consistency.
Terzic will be without Jamie Bynoe-Gittens for the rest of the season after the forward hurt his shoulder and needed surgery.
"Last week he fell on the shoulder. He was operated on yesterday. He will be out for the next weeks and months," Terzic said.
While Dortmund are fighting for their first Bundesliga title since 2012 and hope Bayern slip up in their remaining games, Gladbach have nothing left to fight for, sitting in 10th place.
Asked whether that could influence their opponents' game, Terzic said: "That does not interest me at all because there is still a lot at stake for us."
"Everyone wearing the Gladbach shirt will want to win the game. We know we need a good performance to win it."
As for any help from their Ruhr rivals in Munich on Saturday, Terzic said that was something that had no impact on his planning.
"It is a thing I cannot influence," Terzic said. "We have to win our three remaining games before we can think of anything else and if we get help from them (Bayern's remaining opponents) I don't care if it is Schalke, Leipzig or Cologne."
