Collison, who has fought off a persistent knee injury to play a key role in the Hammers' battle for promotion to the Barclays Premier League this season, netted twice in the opening period at the Cardiff City Stadium to set the Hammers up nicely for the return fixture at Upton Park on Monday.
"He's done fantastically well and he's taken his goals really, really well," McDonald said.
"He's a goalscoring midfield player, very comfortable on the ball and that's another two to his tally which is great. We've asked everybody to contribute with the goals and he's certainly done that today and he's done very, very well."
McDonald revealed Collison's continuing recovery from the cartilage problems that have plagued his career means the Wales international does not participate in all the Hammers' training sessions. But his strengthening and conditioning programmes are obviously paying dividends, and McDonald is hopeful the successful procedures continue to pay off.
"He's got through it very well and the amount of hard work that goes into it has paid off as well and it's all about just trying to get him onto the pitch," he said. "It seems to be working very well at the moment. He's looking very strong."
Cardiff boss Malky Mackay bemoaned his side's misfortune after the defeat. Mackay paid special attention to Collison's second goal - a volley from the edge of the area which deflected off Liam Lawrence's head, completely wrong-footing Bluebirds keeper David Marshall.
"The second one, it's one of these things that happen in the game - it's luck," he said. "The ball hits somebody and it goes in the opposite corner.
"In the second half we came out and we were much more on the front foot and that's probably why we created the chances we did. On another day they drop in.
"We had a couple in the first half and four or five in the second half that, on another day, something different happens."